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A bloody shoeprint in the snow found at a crime scene.  GClark

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How to package and store blood properly when removing it from a crime scene.
B.Swint

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A more in-depth explanation about bloodstains and how they are packaged.
B.Swint

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How It's Done

Bloodstain Patterns that May be Found

Bloodstains range in both amount of blood and type of pattern-from pools of blood around a body to obvious spatter patterns on the walls to microscopic drops on a suspect's clothing. The shape of the bloodstain pattern will depend greatly on the force used to propel the blood as well as the surface it lands on. Forward spatter from a gunshot wound will typically form smaller droplets spread over a wide area, while impact spatter will form larger drops and be more concentrated in the areas directly adjacent to the action.

Because blood demonstrates surface tension, or cohesive forces that act like an outer skin, a drop of blood dropped at a 90° angle forms a near-perfect spherical shape. A smooth surface, such as tile or linoleum, will cause little distortion of this spherical shaped drop, whereas a rougher surface, such as carpet or concrete, disrupts the surface tension and causes the drops to break apart.

The number and location of stains, as well as the volume of blood influence how much useful information can be gathered. Large amounts of blood, such as if the person bled to death or was so severely injured that the resulting blood spatter was extensive, can often yield less information than several well-defined spatter patterns. Too much blood can disguise spatter or make stain patterns unrecognizable. Conversely, too little blood, just one or two drops, will likely yield little or no useable information.

Stains that overlap or come from multiple sources present challenges to analysts, but often reveal valuable details about the crime. Overlapping stains may obscure pattern details, but can provide information on the force, timing and instrument used. In the case of multiple victims, analysts will often use DNA profiling to determine whose blood is included in a given pattern, helping to estimate the locations of the victims in relation to each other and the perpetrator(s). Learn more about DNA ▸

How Bloodstain Evidence is Collected

Bloodstain samples can be collected for BPA by cutting away stained surfaces or materials, photographing the stains, and drying and packaging stained objects. The tools for collecting bloodstain evidence usually include high-quality cameras (still and video), sketching materials, cutting instruments and evidence packaging.

Documentation of Bloodstain Evidence

The most frequently used method of capturing bloodstains is high-resolution photography. A scale or ruler is placed next to the bloodstain to provide accurate measurement and photos are taken from every angle. Video and sketches of the scene and the blood stains is often used to provide perspective and further documentation. This is commonly done even if stained materials or objects are collected intact. Learn more about Crime Scene Photography ▸

Sampling Bloodstains For DNA Profiling

Analysts or investigators will typically soak up pooled blood, or swab small samples of dried blood in order to determine if it is human blood and then develop a DNA profile. This becomes critical when there are multiple victims. DNA profiling may also indicate whether the perpetrator was injured during the attack, as in the case of two DNA profiles found at a scene with only one known victim.

Whenever possible, analysts or crime scene investigators try to collect the evidence intact. This may require removing a section of a wall or carpeting, furniture, or other large objects from the crime scene and sending them to the laboratory for analysis. Items that cannot be removed, such as a section of concrete flooring, will be thoroughly photographed and documented. Learn more about Crime Scene Investigation ▸

Who Conducts the Analysis

Bloodstain pattern analysts can be found at all levels of crime scene investigation: from law enforcement to laboratory staff. Analysts investigate and study patterns at the scene and often screen and profile the blood in the laboratory as well. It has become more common for bloodstain pattern analysts to have a degree in math or a physical science, such as biology, chemistry or physics. This helps the analyst to corroborate findings from other scientific disciplines including pathology, toxicology and serology/DNA. Analysts are typically required to undergo formal training in blood pattern analysis, accompanied by competency testing and periodic continuing education. Certification is offered by International Association for Identification (IAI) but is usually not required.

The FBI's Scientific Working Group on Bloodstain Pattern Analysis (SWGSTAIN) maintains guidelines for minimum education and training for bloodstain pattern analysts.

How and Where the Analysis is Performed

Bloodstain analysts use established scientific methods to examine bloodstain evidence at a crime scene including information gathering, observation, documentation, analysis, evaluation, conclusion and technical (or peer) review. All tests and experiments should be able to be reproduced by independent analysts to ensure accuracy and quality.

Outside consultants are used frequently depending on whether there are any trained analysts in the jurisdiction. The location of the analysis will also depend on the complexity of the case and whether expertise beyond that of the local analyst is required.

Bloodstain pattern analysis is performed in two phases: pattern analysis and reconstruction.

1. Pattern Analysis looks at the physical characteristics of the stain patterns including size, shape, distribution, overall appearance, location and surface texture where the stains are found. Analysts interpret what pattern types are present and what mechanisms may have caused them.

2. Reconstruction uses the analysis data to put contextual explanations to the stain patterns: What type of crime has occurred? Where is the person bleeding from? Did the stain patterns come from the victim or someone else? Are there other scene factors (e.g. emergency medical intervention, first responder activities) that affected the stain patterns?

To help reconstruct events that caused bloodshed, analysts use the direction and angle of the spatter to establish the areas of convergence (the starting point of the bloodshed) and origin (the estimation of where the victim and suspect were in relation to each other when bloodshed occurred).

To find the area of convergence, investigators typically use string to create straight lines through the long axis of individual drops, following the angle of impact along a flat plane, for instance the floor or wall where the drops are found. Following the lines to where they intersect shows investigators where the victim was located when the drops were created.

To find the area of origin, investigators use a similar method but also include the height calculations. This creates a 3-D estimate of the victim's location when the drops occurred. For example, if the area of origin is determined to be only two feet above the area of convergence on the floor, the analyst may presume the victim was either lying or sitting on the floor. If it is five feet above the convergence, the victim may have been standing. This analysis can be done using strings and a protractor, mathematical calculations or computer models.

Tools used to determine area of convergence and area of origin include:

Elastic strings and protractors

Mathematical equations - (tangent trigonometric function)

Computer software programs such as BackTrack™ or Hemospat

Limiting angles method, which examines the physical evidence to exclude angles from analysis (e.g. if blood is found on the underside of a desk or table, analysts know that at least a portion of the spatter-producing event took place below the height of the desk or table.)

BPA can range from investigation and analysis of bloodstain patterns at the crime scene to bench work in the laboratory analyzing and DNA profiling the blood. Limited analysis can also be done using only photographs of the scene.
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Bloodstains range in both amount of blood and type of pattern-from pools of blood around a body to obvious spatter patterns on the walls to microscopic drops on a suspect's clothing. The shape of the bloodstain pattern will depend greatly on the force used to propel the blood as well as the surface it lands on.

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Different ways in which wet and dry blood can be collected in a crime scene.
B.Swint

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The collection and preservation of blood stain evidence is important because this evidence can be used to type blood or run DNA analysis.

There are two different types of blood that can be collected at a crime scene: liquid and dried blood. Liquid blood evidence is generally collected from blood pools but can be collected off of clothing as well, using a gauze pad or a sterile cotton cloth. Once the sample is collected it must be refrigerated or frozen and brought to the laboratory as quickly as possible. The sample must first be dried thoroughly at room temperature. It is important to get the sample to the laboratory as quickly as possible because after 48 hours the sample might be useless. If the sample has to be mailed it should be completely air dried before packaging. If the sample isn't completely dry when it needs to be packaged, the sample should be rolled in paper and labeled and then put into either a brown paper bag or a box. The paper bag or box is then sealed and labeled again. It is important to only place one item per container to avoid contamination and samples should not be placed in plastic containers. Samples shouldn't be in plastic containers because if the sample is still damp the moisture from the sample can cause microorganisms that can destroy the evidence. Also, due to this fact, samples should not be in any container for more than two hours.

Dried bloodstains can be found on small objects, larger objects and on clothing. When dried blood is found on a small object the entire object can be sent to the lab after it's been properly packaged and labeled. When dried blood is found on a larger object that is transportable, an investigator should cover the stained area with paper and tape the paper to the object to avoid contamination. If the object that is stained is not transportable there are different ways that an investigator can collect the sample. One option is to cut out the stained area of the large object. If the portion is cut out the sample is packaged the same way as described above but a control sample should also be provided in a separate package. Another option is to use fingerprint tape and lift the sample as well as the surrounding control area. If this method is used it is important for investigators to not touch the sticky side of the tape with bare hands and the investigator should run an eraser or some type of blunt object over the placed tape to ensure that contact is made with the dried stain. The lifted stain is then be packaged and labeled, then delivered to the laboratory. Another way to collect a sample off of an object is to use a clean sharp object to scrape flakes of the stain into a paper packet. The last two methods of collection of a dried bloodstain on a large object require the use of distilled water to dampen the stain before rolling a thread in the stain or absorbing the stain with a cotton square. These two methods are not recommended due to the risk of contamination. When dried blood is found on clothing the entire article of clothing should be packaged and labeled and delivered to the lab.

It is important for the investigator to remember to keep each sample separated so that there is no contamination between samples.

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Blood Evidence: Collection and Preservation - Crime Museum

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The collection and preservation of blood stain evidence is important because this evidence can be used to type blood or run DNA analysis. There are two different types of blood that can be collected at a crime scene: liquid and dried blood.

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An infamous case that deals with blood splatter analysis.
B.Swint

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One infamous case that comes to the minds of many people when thinking about blood spatter analysis involves a line that has since become a pop-culture catchphrase (thanks to Meryl Streep in "A Cry in the Dark" and Julia Louis-Dreyfus on "Seinfeld"): "The dingo ate my baby."

In August 1980, the Chamberlain family camped near Uluru (formerly known as Ayers Rock) in the Red Centre desert of Australia's Northern Territory. One night, Lindy Chamberlain put two of her children, 4-year-old Reagan and 9-week-old Azaria, to bed in their tent. When she returned, the story goes, she cried, "The dingo's got my baby!" [source: Latson]

According to Lindy, when she got to the tent she saw a dingo with a bundle in its mouth. She wasn't close enough to see what it was, but when she checked on the children she saw that her daughter Azaria was missing [source: Haberman]. As the cry went out, she and her husband, Michael, along with other campers, began searching for the child. A nearby camper, Sally Lowe, went into the tent to check on the still-sleeping Reagan. Seeing a pool of wet blood on the floor of the tent, she thought that Azaria was probably already dead [source: Linder].

When a tourist found the baby's jumpsuit, it was only slightly torn and bloody, but mostly intact. Though an initial investigation backed up Lindy Chamberlain's claim of a wild dog attacking her daughter, it was not long before the parents themselves stood accused [source: Haberman].

The baby had been wearing other clothes that weren't found at the time [source: Latson].

Throughout the case, the local police improperly handled blood spatter and other evidence. Forensics investigators found "blood stains" in the family car and concluded that Lindy had taken Azaria there to cut her throat. Later analysis revealed that the stains came from a spilled drink and a sound-deadening compound that came with the car. One expert identified a "bloody hand print" on Azaria's jumpsuit that later analysis revealed to be red desert sand. However, in 1982, expert testimony - and public opinion - proved enough to convict Lindy Chamberlain of murder and her husband of being an accessory to murder. The baby's knit jacket, found in 1986 near a dingo lair, helped exonerate the Chamberlains after Lindy had served three years of a life sentence, but several years of trials and hearing were yet to come [source: Latson]. In 2012, 32 years after the event, a coroner finally pronounced that a dingo was responsible for the death [sources: Haberman, Latson].

The Chamberlain case shows what can happen when people involved in handling and analyzing blood evidence lack proper training, or when investigators allow public opinion or preconceived notions to influence their analysis.

Related Articles

More Great Links

Sources

Akin, Louis. "Directional Analysis of Blood Spatter at Crime and Accident Scenes for the Private Investigator." The Forensic Examiner. Summer 2005. http://www.akininc.com/PDFs/Directional%20Analysis%20for%20PI's%20condensed.pdf

Brodbeck, Silke. "Introduction to Bloodstain Pattern Analysis." SIAK-Journal - Journal for Police Science and Practice. Vol. 2. Pages 51-57. 2012. (Oct. 14, 2015) http://www.bmi.gv.at/cms/bmi_siak/4/2/1/ie2012/files/brodbeck_ie_2012.pdf

Cotton, Fred B. "Justice Applications of Computer Animation." SEARCH Technical Bulletin. Iss. 2. 1994. (Oct. 16, 2015) http://www.search.org/files/pdf/tbanimat.pdf

Dallas Learning Solutions. "The Chemistry of Life." (Oct. 12, 2015) https://dlc.dcccd.edu/biology1-2/water

Dutelle, Aric W. "An Introduction to Crime Scene Investigation." Jones & Bartlett Publishers. Jan. 28, 2011.

Eckert, William G. and Stuart H. James. "Interpretation of Bloodstain Evidence at Crime Scenes." CRC Press. 1999.

Evans, Collin. "Murder 2: The Second Casebook of Forensic Detection." John Wiley & Sons. 2004.

Genge, N.E. "The Forensic Casebook: The Science of Crime Scene Investigation." Ballantine Books. 2002.

Haberman, Clyde. "Vindication at Last for a Woman Scorned by Australia's News Outlets." The New York Times. Nov. 16, 2014. (Oct. 14, 2015) http://www.nytimes.com/2014/11/17/us/vindication-at-last-for-a-woman-scorned-by-australias-news-media.html?_r=0

Hueske, Edward E. "Practical Analysis and Reconstruction of Shooting Incidents." CRC Press. Nov. 29, 2005.

International Association for Identification. https://www.theiai.org/

International Association of Bloodstain Pattern Analysts. "Bloodstain Pattern Analysis & Other Course(s) (Fall 2015)." (Oct. 5, 2015) http://www.iabpa.org/uploads/files/Training%20Page%20Documents/Brochure%20Courses%20Loci%20Forensics%20B.V.%20-%20Fall%202015.pdf

Iowa State University. "Iowa State Engineer Working to Put More Science Behind Bloodstain Pattern Analysis." April 18, 2013. (Oct. 12, 2015) http://www.news.iastate.edu/news/2013/04/18/bloodstains

James, Stuart H. et al. "Forensic Science: An Introduction to Scientific and Investigative Techniques, Fourth Edition." Taylor & Francis. Jan. 13, 2014.

James, Stewart H. et al. "Principles of Bloodstain Pattern Analysis: Theory and Practice." CRC Press. 2005.

Latson, Jennifer. "Why that 'Dingo's Got My Baby' Line isn't Funny." Time. Oct. 29, 2014. (Oct. 14, 2015) http://time.com/3537456/dingo-got-my-baby/

Linder, Douglas O. "The Trial Transcript in Crown v Lindy and Michael Chamberlain ("The Dingo Trial"): Selected Excerpts." Famous Trials. (Oct. 14, 2015) http://law2.umkc.edu/faculty/projects/ftrials/chamberlain/chamberlaintranscript.html

Murray, Elizabeth. "Blood Spatter Lecture." Marshall University College of Science. Feb. 19, 2008. (Oct. 26, 2015) http://www.science.marshall.edu/murraye/2008%20Forensics%20Lectures/Blood%20Spatter%202008color.pdf

National Forensic Science Technology Center. "Blood Spatter Animations." 2008. http://gallery.nfstc.org/swf/BloodSpatters.html

Nickell, Joe and John F. Fischer. "Crime Science: Methods of Forensic Detection." University Press of Kentucky. 1999.

Ramsland, Katherine. "The Forensic Science of C.S.I." Berkeley Boulevard. 2001.

Red Rocks Community College. "The Many Faces of Criminal Justice." 2014. (Oct. 15, 2015) http://www.rrcc.edu/criminal-justice/criminal-justice-careers#blood

Rosina, J. et al. "Temperature Dependence of Blood Surface Tension." Physiological Research. Vol. 56 (Suppl. 1). Pages S93-S98. 2007. (Oct. 12, 2015) http://www.researchgate.net/publication/6283606_Temperature_dependence_of_blood_surface_tension

Shen, A.R. et al. "Toward Automatic Blood Spatter Analysis in Crime Scenes." Proceedings of the Institution of Engineering and Technology Conference on Crime and Security. Page 378. 2006. http://mi.eng.cam.ac.uk/research/projects/BloodSpatter/BloodSpatter_ShenBrostow.pdf

Slemeko, Joe. "Bloodstain Tutorial." Joseph Slemeko Forensic Consulting, 2007. http://www.bloodspatter.com/BPATutorial.htm

Wonder, Anita Y. "Bloodstain Patterns: Identification, Interpretation and Application." Academic Press. Dec. 17, 2014. (Oct. 12, 2015)

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One infamous case that comes to the minds of many people when thinking about blood spatter analysis involves a line that has since become a pop-culture catchphrase (thanks to Meryl Streep in "A Cry in the Dark" and Julia Louis-Dreyfus on "Seinfeld"): "The dingo ate my baby."

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Blood usually has two different forms, dry and wet. They are contained in different manners and need to be handled differently. This explains how to carefully pick up and package differnt types of blood stains.
-A. Grayer

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The collection and preservation of blood stain evidence is important because this evidence can be used to type blood or run DNA analysis.

There are two different types of blood that can be collected at a crime scene: liquid and dried blood. Liquid blood evidence is generally collected from blood pools but can be collected off of clothing as well, using a gauze pad or a sterile cotton cloth. Once the sample is collected it must be refrigerated or frozen and brought to the laboratory as quickly as possible. The sample must first be dried thoroughly at room temperature. It is important to get the sample to the laboratory as quickly as possible because after 48 hours the sample might be useless. If the sample has to be mailed it should be completely air dried before packaging. If the sample isn't completely dry when it needs to be packaged, the sample should be rolled in paper and labeled and then put into either a brown paper bag or a box. The paper bag or box is then sealed and labeled again. It is important to only place one item per container to avoid contamination and samples should not be placed in plastic containers. Samples shouldn't be in plastic containers because if the sample is still damp the moisture from the sample can cause microorganisms that can destroy the evidence. Also, due to this fact, samples should not be in any container for more than two hours.

Dried bloodstains can be found on small objects, larger objects and on clothing. When dried blood is found on a small object the entire object can be sent to the lab after it's been properly packaged and labeled. When dried blood is found on a larger object that is transportable, an investigator should cover the stained area with paper and tape the paper to the object to avoid contamination. If the object that is stained is not transportable there are different ways that an investigator can collect the sample. One option is to cut out the stained area of the large object. If the portion is cut out the sample is packaged the same way as described above but a control sample should also be provided in a separate package. Another option is to use fingerprint tape and lift the sample as well as the surrounding control area. If this method is used it is important for investigators to not touch the sticky side of the tape with bare hands and the investigator should run an eraser or some type of blunt object over the placed tape to ensure that contact is made with the dried stain. The lifted stain is then be packaged and labeled, then delivered to the laboratory. Another way to collect a sample off of an object is to use a clean sharp object to scrape flakes of the stain into a paper packet. The last two methods of collection of a dried bloodstain on a large object require the use of distilled water to dampen the stain before rolling a thread in the stain or absorbing the stain with a cotton square. These two methods are not recommended due to the risk of contamination. When dried blood is found on clothing the entire article of clothing should be packaged and labeled and delivered to the lab.

It is important for the investigator to remember to keep each sample separated so that there is no contamination between samples.

Back to Forensic Investigation

Back to Crime Library

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Blood Evidence: Collection and Preservation - Alcatraz East Pigeon Forge

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The collection and preservation of blood stain evidence is important because this evidence can be used to type blood or run DNA analysis. There are two different types of blood that can be collected at a crime scene: liquid and dried blood.

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This is another site which tells a lot about properly handling, what happens when not handled carefully, and techniques for packaging for a crime scene. Packaging in a cautios,precise, and timely manner is key.
-A. Grayer

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George Schiro
Forensic Scientist
Louisiana State Police Crime Laboratory

Preliminary Considerations

Since blood evidence associated with a crime can provide information that may solve the case, it is essential to correctly document, collect, and preserve this type of evidence. Improperly handled blood evidence can weaken or destroy a potential source of facts in a case. Properly collected and preserved blood evidence can establish a strong link between an individual and a criminal act. Blood evidence or the lack of blood evidence can also be used to bolster or contradict a witness statement or any statements that the suspect may make. Blood evidence can also point the investigator in the direction he or she needs to go to solve the case. If blood evidence is documented, collected, and stored suitably, it can be presented to a judge or jury several years from the time of the criminal act. Perhaps the most powerful application of blood evidence is the ability to absolutely eliminate a person as a potential suspect in a crime.

Communication is the key to effectively processing blood evidence. Clear and open communication must exist between a crime scene's first responding officer, the case detective, the crime scene investigator, the forensic scientist analyzing the evidence, and the assistant district attorney handling the case. Of prime importance is the communication between the crime scene investigator and the forensic scientist. A crime scene investigator should know the crime lab's capabilities, the methods of blood collection and preservation preferred by the crime lab, the investigative information relevant to the forensic scientist, and the type of reference samples required by the crime lab. This information may change periodically as technology changes, lab policies change, lab personnel change, or lab administrations change. The preferences of forensic scientists also vary from lab to lab. A good method of blood evidence collection for one forensic scientist may not be a good method for another forensic scientist. The crime scene investigator should meet regularly with his or her crime lab's forensic scientists to determine the most suitable manner for collecting and preserving blood evidence. This ensures that the evidence is collected efficiently and effectively.

The technological state of blood evidence analysis has rapidly advanced in the last 20 years. ln the early seventies, most crime labs relied upon the ABO blood grouping system to characterize bloodstains. This meant that the blood could have come from 4 to 49% of the population. In the 1990's, most crime labs are relying on DNA analysis to characterize bloodstains. A blood source can now be statistically narrowed down to one person out of several million or even several billion. (1) A crime scene investigator should know which method or methods of bloodstain analysis are available from his or her crime lab, the FBI lab, and private labs.

Currently, bloodstain analysis falls into three broad categories. A crime lab may use one, two, or all three methods when analyzing blood. These three categories are:

Conventional serological analysis

Analysis of the proteins, enzymes, and antigens present in the blood. These substances are more susceptible to degradation than DNA and this type of testing usually requires a "large" sample (quarter size) in good condition for optimal results. This type of testing is rarely statistically individualizing.

Restriction Fragment Length Polymorphism (RFLP) DNA analysis

Direct analysis of certain DNA sequences present in the white blood cells. DNA is much less susceptible to degradation than proteins, enzymes, and antigens. RFLP DNA testing is commonly statistically individualizing (one out of several million or several billion) and it has withstood rigorous court challenges on its validity. This method also usually requires a "large" sample size to obtain significant results.

Polymerase Chain Reaction (PCR) DNA analysis

Analysis of certain DNA sequences that have been copied multiple times to a detectable level. PCR based testing works well on degraded samples and "small" samples (pinhead size). Currently, it is not as statistically individualizing as RFLP analysis; however, more DNA sequences for PCR analysis are being discovered and in the near future it will be as statistically individualizing as RFLP. PCR based technologies have also withstood rigorous court challenges on its validity. Recently, there has been some concern over the possibility of incidental contamination giving false results in PCR tests. At least one study has shown that if PCR protocols are followed, it is not likely that incidental contamination will give false results. The only way that false results were induced was by direct cross contamination of wet samples. (2)

Presently, the courts do not recognize blood evidence as evidence that can be absolutely linked to an individual, such as fingerprints, bitemarks, broken fingernails, and handwriting. If DNA analysis is utilized, then blood evidence falls into the category of evidence that can be linked to an individual with a high degree of probability. Originally, RFLP DNA analysis was given the misnomer "DNA fingerprinting." The courts have since ruled that a DNA result can only be given in statistical terms. A forensic scientist cannot testify that a bloodstain came from a specific individual. He or she can testify that based on population studies, only one person in several million or billion has a particular DNA profile. He or she can then testify if the suspect or a victim has that DNA profile.

Before a crime scene investigator begins documenting and collecting blood evidence, he or she must recognize the value of this evidence and how it fits in the overall events associated with the crime. The most common applications of blood evidence are:

1. Finding blood with the victim's genetic markers (ABO blood type, DNA profile, etc.) on the suspect, on something in the suspect's possession, or something associated with the suspect (such as the suspect's fingerprints).

2. Finding blood with the suspect's genetic markers on the victim, on something in the victim s possession, or something associated with the victim.

3. Investigative information determined from blood spatter and/or blood location.

Generally, blood evidence is usually more informative in cases where a suspect and victim are in contact or close proximity. For example, if a suspect stabs or beats a victim, there could be an exchange of blood between the victim and the suspect. If a suspect shoots a victim from across a room. It is less likely that an exchange of blood will occur.

Occasionally, investigators blindly collect blood samples from a scene without any thought about the facts they are trying to establish. An example is a crime scene consisting of the body of a shooting victim found alone in his residence. Some investigators will collect several blood samples from around the body. This is unnecessary since it will only establish that the victim bled at the scene of the crime. This fact is already proven by the presence of the body; however, one sample of pooled blood next to the body can be collected to confirm the results obtained from the victim's reference blood sample.

The crime scene investigator must make an effort to collect the evidence that is going to provide the most useful information in establishing the facts about a crime scene. The investigator must balance this with the philosophy of too much evidence collected is better than not enough evidence collected. The investigator should concentrate on collecting representative samples of the "peripheral" bloodstains, such as the bloodstains that are away from the body and the main area of action, or blood spatter patterns that differ from the majority of the blood spatter patterns. These bloodstains may provide useful investigative information. The investigator should also search for blood trails leading away from the scene. These trails could have originated from a wounded suspect. If a suspect is established in a case, then he or she should be examined for wounds. The suspect's wounds should be documented and photographed. This is additional useful evidence if blood with the suspect's genetic markers is found in an incriminating location.

Because blood analysis is a comparison analysis (comparison of the victim's blood and the suspect's blood to blood found at the crime scene), reference blood samples are needed from the victim and suspect. A comparison must be made between the genetic markers in the victim s blood and the suspect's blood. The blood samples from the crime scene can then be analyzed for those genetic markers that are different in the suspect and victim. This is especially true in conventional serology analysis. Requests are made occasionally to do an ABO blood type determination of blood on a suspect's clothes to a known blood sample from a victim. This type of analysis is useless without a known blood sample from the suspect. If both parties have the same ABO blood type, then part of the sample has been wasted and no real information of value is produced. If reference samples of blood from both parties are provided, then it can be determined if they have the same ABO blood type. If they do, then further analysis of the reference blood samples may show that the two parties have different PGM types. The unknown stain could then be analyzed for the genetic marker PGM. This analysis may then show the possible origin of the stain.

Suitable reference samples (a suitable reference sample is collected directly from a person into a tube or "Vacutainer") from all of the involved subjects must be sent to the crime lab. An unsuitable reference sample is bloody clothing or some other bloody item. These are unsuitable because the histories of these bloodstained items are usually questionable and there may be factors present on the items that will give misleading results. The sample must be collected in the proper "Vacutainer." The investigator should check with the lab he or she is using to determine the analysts' preferences on reference sample collection tubes. This is a summary of the forensic uses of "Vacutainers":

Yellow Top Vacutainers (contain Acid Citrate and Dextrose solution)

Useful for conventional serological testing and DNA testing (author's personal preference).

Purple Top Vacutainers (contain EDTA)

Useful for DNA testing; may inhibit certain conventional serological tests. (3)

Red Top Vacutainers (no additives)

Useful for conventional serological tests; less useful for DNA testing; can be used for pregnancy and HIV testing (4) (if a yellow top is not available, then the author prefers receiving red top and purple top Vacutainers from a subject).

Gray Top Vacutainers (contain Sodium Fluoride and sometimes EDTA)

Useful for toxicological testing; not suitable for conventional serological analysis (5) and may not be suitable for DNA analysis.

If the investigator is collecting blood from an autopsy, then one of each type of Vacutainer should be collected from the victim. This will insure that any necessary forensic testing can be performed. These Vacutainers should be stored in a refrigerator (not frozen) at about four degrees Centigrade until they are transported to the crime lab.

In recent years, blood visualization enhancing chemicals have regained popularity with crime scene investigators. The chemical of choice is usually luminol. Luminol is a chemical that when applied to bloodstains, even very dilute bloodstains, will cause the bloodstains to glow in the dark. Because it has several drawbacks as a presumptive test for blood, spraying luminol at a crime scene should be an investigator's last resort for detecting blood. The problems with luminol include:

1. One of the empirical tests for determining if a stain is blood is its appearance. If it is a bloodstain, then it should look like blood. A bloodstain also has to be present in sufficient quantity to perform confirmatory testing and testing for genetic markers. This requires that the bloodstain is visible to the naked eye. The luminol reaction is at best a presumptive test for blood. If the stain is so dilute that it can only be visualized with luminol, then no further analysis can be performed to confirm the presence of blood.

2. Luminol will give false reactions. Luminol will react with copper ions, copper compounds, iron compounds, and cobalt ions. It will also react with potassium permanganate (found in some dyes) and hydrated sodium hypochlorite (bleach).(6) Ferricyanide and plant peroxidases could also give false reactions.(7)

3. Studies have shown that luminol will cause the loss of several genetic markers.(8,9)

4. Because luminol is water based, it could cause, latent, possibly bloody impressions to smear. Luminol could also further dilute an already diluted stain. This may push the stain beyond the genetic marker analysis detection limits.

Unfortunately, some crime scene investigators use luminol as their first choice for detecting blood. By using luminol in such a reckless manner, it is possible to lose valuable information from a bloodstain. When searching for blood at a crime scene, especially blood that may have been cleaned up, the investigator should first use a high intensity light to search for any traces of blood. Bloodstains are not easy to eradicate. Diluted blood will often leave a brownish stain where a person has tried to clean it. Blood also has a tendency to flow into floorboard cracks, into carpet padding, behind baseboards, etc. By conducting a thorough examination with a high intensity light source, the investigator can usually find these areas. These items can then be removed or collected and submitted to the crime lab for confirmatory testing.

Because luminol is so sensitive to dilute bloodstains, it is occasionally used to enhance bloody impressions (shoeprints, fingerprints, etc.). Luminol is not the best reagent for enhancing these impressions because of its water base. Better methods for enhancing bloody impressions use either rapidly evaporating organic solvents (such as merbromin and ortho-tolidine) or they use a water based chemical after treating the impression with a fixative (such as the amido black staining technique).

Once the investigator realizes the potential of blood evidence as well as problem areas in documenting, collecting, and preserving this type of evidence, he or she will be more effective in finding the best bloodstains. Some commonly encountered problems are lack of communication (especially between the investigators and the forensic scientists), unfamiliarity with the types of bloodstain analysis, lack of knowledge about which stains will yield the most useful information, poor reference samples, and indiscriminately using luminol at crime scenes. If these problems are solved, then the blood collection and analysis should progress without any major problems.

Documentation and Examination of the Crime Scene

An investigator should take a slow and methodical approach to collecting and preserving evidence. The only time that an investigator should make rapid decisions concerning evidence is when the evidence is in danger of being destroyed or compromised. In that case, the evidence should be preserved, or documented and collected as quickly as possible. Before setting foot in the crime scene, the investigator must gather as much information as possible to determine the scope and value of any evidence that may be present. This information may include witness statements, suspect statements, victim statements, information from the first responding officer, information from the detectives, etc. Information is collected to prevent the destruction of any valuable and/or fragile evidence such as shoeprints, trace evidence, etc. The investigator should then use logic and common sense to search for evidence; however, he or she should also use imagination and avoid becoming narrow-minded. As investigators become more experienced, they know that certain patterns emerge and certain elements are common among similar cases. They also know that they have to keep an open mind when deciding what is evidence and where it will be found. This is due to the unpredictable nature of people and the forces of chaos. Once the investigator has gathered as much information as possible about the case, then he or she should form a mental or written plan to proceed with the documentation, collection, and preservation of the evidence. The investigator should also pass any relevant information to the lab analyst. This will allow the analysis to make decisions concerning the best approach to the analysis and what information can be determined from the evidence.

The investigator should thoroughly document every aspect of the crime scene investigation from the initial walk through to the securing of the collected evidence. Documentation is necessary to record the condition of the crime scene and its related evidence as closely as possible to their original condition at the time of the crime. Of course, there is usually some alteration of the scene that will occur between the time of the crime and the time that the scene is documented. EMS personnel, police officers, and fire fighters may have to alter the original scene in the course of performing life saving measures. Other people entering the scene may also unknowingly or unconsciously alter the scene. ln any case, the evidence must be documented in as pristine a condition as circumstances allow. The investigator has a number of tools available for documenting evidence including notes, videotape, photographs, sketches, and chain of custody forms. The investigator may elect to use several or all of these methods of documentation. This documentation will also be used in the future to refresh the investigator's memories of the case.

The first tool for documenting the crime scene investigation is note taking. An investigator should be as thorough as possible when taking notes. All of the pertinent times and actions taken should be recorded, such as who contacted the investigator and when; when did the investigator leave for the crime scene; when did the investigator arrive at the scene; what actions were taken by the investigator and when; when did the investigator leave the scene, etc. Notes should be recorded throughout the entire crime scene investigation.

Examination of the crime scene will usually begin with a walk through of the area along the "trail" of the crime. The trail is that area where all apparent actions associated with the crime took place. This trail is usually marked by the presence of evidence. Point of entry, location of a body, areas where the suspect may have cleaned up, and the point of exit are all included in the trail. The purpose of the walk through is to note the location of potential evidence and to mentally outline how the scene will be processed. The walk through begins as close to the point of entry as possible. The first place the investigators should examine is the ground on which they are about to tread. If any evidence is found, then a marker should be placed at the location as a warning not to step on the item of interest. When searching for blood evidence, it is important to use a high intensity light. A high intensity light source will aid in the visualization of bloodstains, even stains that have been diluted. The light source can also be used to provide oblique (side) lighting. Oblique lighting is an excellent tool for finding trace evidence and other small items of interest.

As the walk through progresses, the investigators should make sure their hands are occupied by either carrying notebooks, flashlights, pens, etc. or by keeping their hands in their pockets. This prevents the investigator from depositing unwanted fingerprints at the crime scene. As a final note on the walk through, the investigators should examine the areas above their heads (ceiling, tree branches, etc.). These areas may yield blood spatters, bullet holes, etc. Once the walk through is completed, the notes must be supplemented with other forms of documentation, such as videotape, photographs, and/or sketches.

Videotape can be an excellent medium for documenting bloodstains at a crime scene. If a video camera is available, it is best used after the initial walk through. This is to record the evidence before any major alterations have occurred at the scene. Videotape provides a perspective on the crime scene layout that cannot be as easily perceived in photographs and sketches. It is a more natural viewing medium to which people can readily relate, especially in demonstrating the structure of the crime scene and how the evidence relates to those structures.

The value of videotaping blood evidence is that the overall relationship of various blood spatters and patterns can be demonstrated. One example of this could be a beating homicide. In this case, videotape can show the overall blood spatter patterns and how these spatters are inter related. The videotape can also show the relationship of the spatters to the various structures at the crime scene. In cases where the suspect may have been injured (such as stabbing homicides), the video camera can be used to document any blood trails that may lead away from the scene. If videotaping indoors, the camera can show how the various areas are laid out in relation to each other and how they can be accessed. This is particularly valuable when recording peripheral bloodstains that may be found in other rooms. The high intensity light source can also be used for illuminating the bloodstains to make them more visible on the videotape.

Whether a video camera is available or not, it is absolutely essential that still photographs are taken to document the crime scene and any associated blood evidence. If a video camera is available, then still photography will be the second step in recording the crime scene. If video is not available, then still photography will be the first step. Photographs can demonstrate the same type of things that the videotape does, but crime scene photographs can also be used to record close up details, record objects at any scaled size, and record objects at actual size. These measurements and recordings are more difficult to achieve with videotape.

Blood evidence can be photographed using color print film and/or color slide film. Infrared film can also be used for documenting bloodstains on dark surfaces. Overall, medium range, and close up photographs should be taken of pertinent bloodstains. Scaled photographs (photographs with a ruler next to the evidence) must also be taken of items in cases where size relevance is significant or when direct (one-to-one) comparisons will be made, such as with bloody shoeprints, fingerprints, high velocity blood spatter patterns, etc. A good technique for recording a large area of blood spatter on a light colored wall is to measure and record the heights of some of the individual blood spatters. The overall pattern on the wall including a yard stick as a scale is then photographed with slide film. After the slide is developed, it can be projected onto a blank wall or onto the actual wall many years after the original incident. By using a yardstick, the original blood spatters can be viewed at their actual size and placed in their original positions. Measurements and projections can then be made to determine the spatters' points of origin.(10)

Another method of documenting blood evidence is by drawing a sketch of the crime scene. The drawback of photographs is that they are two-dimensional representations of three dimensional objects. As a result, photos can distort the spatial relationships of the photographed objects causing them to appear closer together or farther apart than they actually are. If spatial relationships of the evidence are important or if something needs to have proportional measurements included in it for calculations (such as blood spatter patterns) then a sketch must be made.

Computer programs are available for sketching crime scenes and blood spatters by inputting certain measurements associated with the scene and the individual spatters. This blood spatter program will then calculate and draw the spatters' points of origin. These programs might come in handy where there are many blood spatters and the points of origin need to be determined. For more in depth information on videotaping, photographing, and sketching crime scenes, refer to the recommended reading list.

The final method of evidence documentation is the chain of custody form. The chain of custody form is a written record of all evidence transfers from the crime scene to possession of the court or the clerk of court. Proper chain of custody thoroughly documents the movement of evidence, the security of the evidence, who had possession of the evidence, and when the evidence was in a person's possession. The chain of custody form must accompany the evidence all the way to its final destination. A copy should also be kept in the case folder. The following information must be recorded on the form: A description of the evidence and its container; the specific recovery location of the evidence; case numbers; the date and time it was collected; who collected it; whether or not the evidence container was sealed upon transfer to another individual; who received the evidence; the dates and times of any evidence transfers; who delivered the evidence; and the final disposition of the evidence. This is necessary to demonstrate that the evidence was not contaminated in a way to alter the information that the evidence originally contained. It also demonstrates that the original evidence was not planted or changed in some way before its presentation in court. After the evidence has been documented using videotape, photographs, sketches, and chain of custody forms, the evidence collection process can begin.

Earn a Degree in Crime Scene Investigation, Forensic Science, Computer Forensics or Forensic Psychology

Collection and Preservation of Blood Evidence

Once the crime scene has been thoroughly documented and the locations of the evidence noted, then the collection process can begin. The collection process will usually start with the most fragile or most easily lost evidence. Special consideration can also be given to any evidence or objects that need to be moved. Collection can then continue along the crime scene trail or in some other logical manner. Photographs should continue to be taken if the investigator is revealing layers of evidence that were not previously documented because they were obscured.

Most items of evidence will be collected in clean, unused paper containers such as packets, envelopes, and bags. Moist or wet biological evidence (blood, body fluids, plants, etc.) from a crime scene can be collected in clean, unused plastic containers at the scene and transported back to an evidence receiving area if the storage time in sealed plastic is less than two hours and this is done to prevent contamination of other evidence. Once in a secure location, wet evidence, whether packaged in plastic or paper, must be removed and allowed to completely air dry. That evidence can then be repackaged in a new, clean, unused, dry paper container. UNDER NO CIRCUMSTANCES SHOULD EVIDENCE CONTAINING MOISTURE BE SEALED IN PLASTIC OR PAPER CONTAINERS FOR MORE THAN TWO HOURS. Moisture allows the growth of microorganisms that can destroy or alter evidence.

Any items that may cross contaminate each other must be packaged separately. The containers should be closed and secured to prevent the mixture of evidence during transportation. Each container should have the collecting person's initials: the date and time it was collected; a complete description of the evidence and where it was found; and the investigating agency's name and file number.

Before transporting any items of evidence, the investigator should examine the items to determine if there is any loose trace evidence (hairs, fibers, paint chips, etc.) that may be lost in transportation. If there is, then this loose evidence should be collected in a paper packet and placed in an envelope. The envelope should have the required information giving a description and the source of the trace evidence. The actual item can then be processed and collected.

Blood evidence must never be exposed to excessive heat or humidity. If possible, the bloodstained evidence should be refrigerated until it can be transported to the crime lab. The evidence should also be taken to the lab as soon as possible. The following are guidelines, listed in order of the author's preferences, for collecting and preserving blood evidence:

ALWAYS TAKE SAFETY PRECAUTIONS WHEN HANDLING BIOLOGICAL
EVIDENCE. BE SURE TO WEAR PROTECTIVE CLOTHING, GLOVES, MASKS,
AND/OR EYE PROTECTION AS THE SITUATION WARRANTS.

Dried Bloodstains

If the bloodstained item is small and transportable, package it in a paper bag or envelope.
Advantages: Requires a minimal amount of interaction with the bloodstains by the investigator: allows the serologist to make the decisions involved in collecting the samples; dilution and contamination potential minimized by eliminating the use of water as the collection medium.
Disadvantages: More work for the serologist: bulky items require more storage space.

If the bloodstained item is large or not easily transported, then the following techniques can be used for collecting the bloodstains. If possible, the investigator should also collect samples from unstained areas of the item for negative controls.

1. Cutting out the portion(s) of item with the bloodstain(s). A negative control area should also be cut out if available. Package cuttings in separate paper envelopes.
Advantages: Dilution and contamination potential minimized by eliminating the use of water as the collection medium: requires only a small amount of investigator interaction with the bloodstain: does not usually take up much storage space.
Disadvantages: Investigator must decide which stains and controls to collect: some materials are harder to cut than others.

2. Tape lifting bloodstains - Place fingerprint tape (do not touch sticky surface with bare hands) over bloodstain and surrounding negative control area. Rub non-sticky side of tape with a pencil eraser or other blunt object. This is to insure that good contact is made between the stain and the tape. Lift the bloodstain like a fingerprint and place the tape on a vinyl acetate backing (do not use a paper backing - paper makes the stain difficult to handle during analysis). The lifting process can be repeated several times on the same stain if necessary. Label the stain(s) and package in a paper envelope.
Advantages: Dilution and contamination potential minimized by eliminating the use of water as the collection medium; negative control is readily collected; requires little storage space; fairly easy technique to perform.
Disadvantages: Investigator must decide which stains to collect; bloodstains do not lift well on certain surfaces.

3. Scraping bloodstains into a paper packet - Use a clean sharp instrument to scrape the bloodstain into a paper packet. The packet can be labeled and placed in a paper envelope. Do not use a plastic container in place of a paper packet because the static charge from the plastic will cause the blood flakes to disperse and stick to the sides of the container. This technique can be combined with the tape lift method by scraping the stain near the tape's sticky side. The static charge will cause the flakes to stick to the tape. The tape can then be placed on vinyl acetate.
Advantages: Dilution and contamination potential minimized by eliminating the use of water as the collection medium; requires little storage space.
Disadvantages: Investigator must decide which stains to collect; when scraped, bloodstains tend to break into small, very hard to handle flakes; the flakes have a tendency to be easily lost during the scraping process (except when used in combination with the tape lift); some surfaces are not easily scraped.

4. Absorbing stains onto moistened 1/2" long threads - Use only distilled or deionized water to moisten clean, 1/2" long, number 8, white cotton threads. Do not handle the threads with bare hands. Place thread on bloodstain with a pair of clean forceps or a clean cotton swab. Roll the thread on the bloodstain, so the stain is absorbed onto the thread. Repeat until a minimum of four threads are collected. Place the threads (and swabs, if used) in a secure area and allow them to air dry. When air dried, package into a paper packet and place in an envelope. For transportation purposes and to prevent cross contamination, the threads may be placed in a plastic container for no more than two hours. Once in a secure location, the threads must be removed from the plastic and allowed to air dry. They may then be repackaged into a paper packet and placed in an envelope. Threads must also be taken from a negative control area, if available.
Advantages: Stain is concentrated onto a small surface area; requires little storage space.
Disadvantages: Dilution and contamination potential introduced by using water (it may be possible to reduce contamination and dilution effects by using acetone or 70% ethanol to collect bloodstains. At least one study has shown that DNA yield can be increased by using either acetone or 70% ethanol to collect bloodstains. The 70% ethanol produced a higher DNA yield.(11)); investigator must decide which stains to collect; threads can be difficult to handle.

5. Absorbing stains onto moistened 1/2" X 1/2" cotton squares - The procedure for collection is the same as for threads, except that white, 100% cotton muslin is used instead of threads. The muslin must be boiled in distilled or deionized water and allowed to air dry prior to its use. This removes interfering factors from the muslin. Do not handle the muslin with bare hands.
Advantages: Stain is concentrated onto a relatively small surface area; easier to handle than threads; requires little storage space.
Disadvantages: Same as for threads, except dilution and contamination potential is increased due to using more water.

Wet Bloodstains

1. If the item is small and transportable, then package it in a paper bag (or plastic bag to prevent contamination of other objects). Bring it to a secured location, take it out of the bag and allow the evidence and the bag to thoroughly air dry. Repackage in the original paper bag or, if necessary, a new paper bag. If a new paper bag is used, then the air dried original container should be packaged with the item of evidence.
Advantages: Requires a minimal amount of interaction with the bloodstains by the investigator; allows the serologist to make the decisions involved in collecting the samples.
Disadvantages: More work for the serologist; bulky items use more storage space.

2. If the bloodstained item is large or not easily transported, then absorb the stain onto a 1" X 1" square of the cotton muslin as described in part 2E under dried bloodstains. Package it in paper (or plastic to prevent contamination of other objects). Bring it to a secured location, take it out of the container and allow the cotton square and the container to thoroughly air dry. Repackage in the original paper container or, if necessary, a new paper container. If a new paper container is used, then the air dried original container should be packaged with the cotton square. If possible, the investigator should also collect samples from unstained areas of the item for negative controls.
Advantages: Requires little storage space; fairly easy technique to perform; stain is concentrated onto a relatively small surface area.
Disadvantages: Investigator must decide which stains and controls to collect; investigator must have direct interaction with bloodstain.

If the investigator has any questions, he or she should contact his or her crime lab or the author.

FOOTNOTES

1. See the testimony of Dr. Robin Cotton on 5/11/95 in the case State of California vs. Oenthal James Simpson.

2. According to the FBI's Biochemical Methods Course Manual, the polymorphic enzyme Peptidase A is inactivated by the presence of metal chelators such as EDTA.

3. Personal communication with Forensic Pathologist Juanito Lim, MD of Earl K. Long Hospital, Baton Rouge, LA.

4. FBI Forensic Serology Course Manual.

5. Scott, S. Elaine, "Bloodstain Pattern Analysis - Five Years Later," Juried Paper presented at the Southern Association of Forensic Scientists' Fall, 1987 Meeting, September 18, 1987, Atlanta, Georgia.

6. Warren. Joseph. "Optimal Medium for the Transfer of Crime Scene Stains for DNA Analysis", Paper presented at the La. Association of Forensic Scientists' Fall, 1991 Meeting, October 26, 1991, Harahan, La.

Recommended Reading

Evidence Handling Guide. La. Dept. of Public Safety and Corrections, Office of State Police, Crime Laboratory.

Fisher, Barry A.J., Arne Svensson, and Otto Wendel. Techniques of Crime Scene Investigation. New York: Elseveir,

Sketching Crime Scenes. U. S. Department of Justice, FBI.

ACKNOWLEDGMENTS

Thanks to my supervisor Jim Churchman and my co-workers Carolyn Booker and Mary Quinn for their reviews and comments. -- GS

by George Schiro
Louisiana State Police Crime Laboratory
P. O. Box 66614
Baton Rouge, LA 70896

Article submitted by the author
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Collection and Preservation of Blood Evidence from Crime Scenes

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Since blood evidence associated with a crime can provide information that may solve the case, it is essential to correctly document, collect, and preserve this type of evidence. Improperly handled blood evidence can weaken or destroy a potential source of facts in a case.

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A bloody shoeprint on the carpet found at a crime scene.
D.Williams

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Whereabouts of blood (or any other DNA evidence) after it is removed from a crime scene.
B.Swint

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How It's Done

Sources of DNA Evidence

The biological material used to determine a DNA profile include blood, semen, saliva, urine, feces, hair, teeth, bone, tissue and cells.

Samples that May be Used

Investigators collect items that could have been touched or worn by persons involved in a crime. The following items may contain DNA material:

Masks

Hats

Gloves

Clothing

Tools

Weapons

Sexual assault evidence kits

Underclothes

Bedding

Dirty laundry

Fingernail scrapings

Cups/bottles

Cigarettes

Toothpicks

Toothbrush

Facial tissue

Hairbrush

Eyeglasses

Condoms

Tape

Ligatures (rope, wire, cords)

Stamps or envelopes

The best evidence occurs when a person's DNA is found where it is not supposed to be. For example, consider a breaking-and-entering that occurred in a residential area. Near the point of forced entry, a knit cap was found which the homeowners confirm was not theirs. Several head hairs were recovered from the inside, one of which had a root with tissue attached, which made it possible to obtain a DNA profile. The DNA profile was used to identify the perpetrator.

As technology advances, forensic scientists are able to analyze smaller and smaller biological samples to develop a DNA profile. For example, if a person touched an object or weapon, skin cells may have been left behind. This low-level DNA is sometimes referred to as "touch DNA". It can even be collected from a victim's skin or bruises where they were handled roughly. Low-level DNA samples may be helpful when examining evidence where it would be difficult to retrieve fingerprints-such as textured surfaces on gun handles or automobile dashboards. However, not all jurisdictions have the capability to process this evidence.

To compare the victim's or suspect's DNA profile to the recovered crime-scene DNA, the laboratory will need to have their known biological samples available for a side-by-side comparison. These known samples are called reference samples. In some jurisdictions, a DNA sample is routinely taken from an arrestee during the process of booking and fingerprinting. However, this is an evolving area of law and states vary in their laws governing the collection of DNA from arrestees. Sometimes a court order is required to retrieve a reference from a person of interest. Reference samples are always collected from victims unless they choose not to cooperate with the investigation; in that case, a court order might be required.

In addition to unknown and reference samples, elimination samples are often collected from consensual sex partners and others, such as first responders, crime scene personnel and analysts working the case so they can be excluded from the investigation.

It is important that biological evidence be properly collected and preserved as it can easily degrade when exposed to heat or humidity. Storing evidence in cool environments is preferred; however, research has shown that room temperature conditions are suitable for storing dried stains as long as the humidity is controlled. Liquid samples should be transported in refrigerated or insulated containers.

Who Conducts DNA Analysis

DNA analysts working in laboratories that participate in the FBI's National DNA Index System (NDIS) and/or are accredited by a recognized organization must meet specific educational and training requirements. At a minimum, a bachelor's degree in biology, chemistry, or a forensic science-related area is required. In addition, the analyst should have successfully completed nine hours of coursework at the undergraduate or graduate level covering the following subject areas: biochemistry, genetics, molecular biology, as well as coursework or training in statistics and/or population genetics, as it applies to forensic DNA analysis.

To ensure analysts' skills are kept up to date, analysts who are actively employed at a crime laboratory are also required to meet continuing education requirements. These requirements are stipulated by the FBI's Quality Assurance Standards (QAS).

The specialists who conduct DNA analysis in the laboratory are referred to by several different titles, including: Crime Laboratory Analyst, Forensic Examiner, Forensic Scientist and Forensic Laboratory Analyst.

How and Where DNA Testing is Performed

DNA testing must be conducted in a laboratory with dedicated facilities and equipment that meet the FBI's stringent QAS requirements. Most publicly funded DNA crime laboratories in the United States are part of state, regional or municipal law enforcement agencies and accept submissions from multiple agencies.

Prior to performing DNA analysis at the laboratory, initial testing is often conducted at the crime scene to determine the type of biological material in question. Screening for the presence of biological materials may also be conducted in the laboratory to determine if a specific biological fluid may be present. Most biological screening tests are presumptive in nature and do not specifically identify a bodily fluid.

To determine who deposited biological material at a crime scene, unknown samples are collected and then compared to known samples taken directly from a suspect or victim.

Most DNA samples submitted to a laboratory undergo the following process:

1. Extraction is the process of releasing the DNA from the cell.

2. Quantitation is the process of determining how much DNA you have.

3. Amplification is the process of producing multiple copies of the DNA in order to characterize it.

4. Separation is the process of separating amplified DNA product to permit subsequent identification.

5. Analysis & Interpretation is the process of quantitatively and qualitatively comparing DNA evidence samples to known DNA profiles.

6. Quality Assurance is the process of reviewing analyst reports for technical accuracy.

How the Results are Interpreted

The DNA analysis process provides the analyst with a chart called an electropherogram, which displays the genetic material present at each loci tested (each of the gray bars on the graph below, except for the last one, correspond to a locus; the final gray area is used to indicate the gender of the individual). In a complete profile, each person will exhibit either one or two peaks (alleles) at each locus. The following electropherogram is an example of a profile from a single individual (i.e., a "single-source" profile):

Loci that display only one allele indicate that the individual inherited the same marker from both parents at this locus. Where two alleles are displayed, the individual inherited different markers.

This image shows that the first four loci from the unknown evidence sample collected at the scene match the sample collected from the suspect. (This process would be repeated for all 13 loci.)

Note: The height of each peak must exceed a predetermined quantity threshold to be used in the analysis.

Is the suspect included?

In practice, evidence often contains a mixture of DNA from more than one person. These mixtures can be very challenging to analyze and interpret. In the following example, each marker from the suspect sample is included in the mixture profile collected from the evidence.

Partial Profiles:

If any locus is missing an allele, this is considered a partial profile. Partial profiles can happen for a variety of reasons, such as when a sample is degraded. If a sample has peaks at every locus, but any of them fall below a predetermined threshold, this would also be considered a partial profile.

Comparing Profiles Against a Central Database

To enable profiles to be searched against a large, national database, the FBI created the National DNA Index System (NDIS) in 1998. This national database is part of the Combined DNA Index System (CODIS) that enables law enforcement agencies throughout the nation to share and compare DNA profiles to help investigate cases. As of 2012, there are more than 10 million DNA profiles in the system and CODIS has produced leads that have assisted in almost 170,000 investigations.

Once a laboratory enters a case into CODIS, a weekly search is conducted of the DNA profiles in NDIS, and resulting matches are automatically returned to the laboratory that originally submitted the DNA profile. CODIS has three levels of operation:

Local DNA Index System(LDIS)

State DNA Index System (SDIS)

National DNA Index System (NDIS)

The NDIS databases contain DNA profiles from:

Convicted Offenders - DNA profiles of individuals convicted of crimes

Arrestees - profiles of arrested persons (if state law permits the collection of arrestee samples)

Forensic unknowns - DNA profiles of unknown individuals developed from crime scene evidence, such as semen stains or blood

Missing Persons - contains DNA reference profiles from missing persons

Biological Relatives of Missing Persons - contains DNA profiles voluntarily contributed from relatives of missing persons

Unidentified Humans (Remains) - contains DNA profiles developed from unidentified human remains

Each database has its own rules regarding the number of STR markers that must be present for the profile to be uploaded. As of January 1, 2017, the National DNA Index System (NDIS) requires that 20 autosomal STR markers be tested, and the profile must contain information for at least 10 loci. The requirements are less stringent for state and local databases. States require the profile to have information for seven or more loci, and the local database requires at least four loci to be present to be uploaded.
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The biological material used to determine a DNA profile include blood, semen, saliva, urine, feces, hair, teeth, bone, tissue and cells. Investigators collect items that could have been touched or worn by persons involved in a crime.

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A closeup image of blood found in the snow.
B.Swint

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A famous case in which bloodstain pattern analysis helped solve this case.
B.Swint

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By: Bill Clutter

The first use of blood stain analysis in an American courtroom occurred in 1966, in the re-trial of Sam Sheppard, an Ohio physician who spent over 10 years in prison before being freed. Sheppard had been convicted in 1954 of bludgeoning his wife to death in her bed, but maintained his innocence, claiming the attack was perpetrated by an intruder. This famous case inspired the TV series The Fugitive (1963-67) and the 1993 movie, starring Harrison Ford. The U.S. Supreme Court vacated the original conviction because of pre-trial publicity that made it impossible to receive a fair trial. F. Lee Bailey, gained fame as a criminal defense lawyer by winning an acquittal on re-trial. Dr. Paul Kirk, a criminologist at the University of California, Berkley, conducted a reconstruction of the crime scene and provided the first expert testimony interpreting for the jury patterns of cast-off and impact spatter bloodstains that were present at the crime scene. His testimony helped win Sheppard's freedom.

However, it was Herbert L. MacDonell, who is credited with establishing the profession of Bloodstain Pattern Analysis (BPA). In 1971, MacDonell wrote Flight Characteristics and Stain Patterns of Human Blood, the first authoritative BPA training manual. In 1983, he organized a meeting of his disciples whom he trained in Corning, NY and organized the International Association of Bloodstain Pattern Analysts (IABPA).

To acquire a better understanding of this specialty, I attended a bloodstain pattern analysis course sponsored by Bevel Gardner & Associates.

THE CAMM CASE: "A BLACK-EYE" TO THE BPA PROFESSION
After giving an overview of BPA history, the instructor mentioned that the bloodstain profession has taken a few hits with the 2009 report from the National Academy of Sciences that was critical of some of the practices of BPA in American courtrooms. He noted that one case in particular, the David Camm case in Indiana, has given the profession "a black eye".

I had watched the CBS 48 Hours story on the Camm case several years earlier, so I was aware that former Indiana State Trooper, David Camm's alibi had been corroborated by eleven men. He had been playing basketball at a church where his uncle was the pastor. The game started around 7 p.m., about the same time that his wife and two children were last seen alive.

The men played basketball for about two hours and David was there the entire time, according to those who played ball with him. At approximately 9:26 p.m. he arrived home and called his old post at the Indiana State Police after finding the bodies of his wife and two children in the garage of their home in Georgetown, Indiana.

David told police he found his wife lying on the floor of the garage. She had a single bullet wound to the head. He found his five-year-old daughter, Jill, in her seat belt in the back seat of his wife's Ford Bronco inside the garage. Jill had been shot once in the head. His son Brad was slumped over the back seat as if he had attempted to escape to the back cargo area when he was shot. David said his son's body felt warm, possibly still alive. David climbed into the back seat, carried his son out of the vehicle and laid him next to his mother so he could perform CPR. Brad died from the single gun-shot wound that entered just under his arm pit. At autopsy, the pathologist found possible evidence of a possible "sexual assault" in Jill's vaginal area which immediately changed the dynamics of the homicide investigation. The demeanor of the questioning toward David became accusatory. However, a week earlier, the child's pediatrician had noticed the same inflammation, but attributed it to aggressive wiping or possibly a reaction to bubble baths. A mandatory reporter, the family doctor was not alarmed. No report of child abuse had been made at that time.

Prosecutors decided to call in a bloodstain pattern "expert" who had a reputation for assisting in the prosecution of cases that were difficult to prove. Two days later, David Camm was arrested for first degree murder, based on an interpretation of eight tiny bloodstains on his t-shirt. The "expert" who had been called to the crime scene interpreted these stains as high velocity impact spatter from allegedly firing the gun that killed his family. Some of the leading experts in BPA, however, disagreed, and said the stains were caused by transfer from coming into contact with his 5 year-old daughter's hair that was saturated with her blood when he removed his son from the vehicle.

Robert Stites was the so-called "expert" in crime scene reconstruction and bloodstain pattern analysis who arrived in New Albany, Indiana to assist Floyd County prosecutor Stan Faith. Stites, however, was merely a crime scene photographer who was working at the direction of Rodney Englert. The real "expert" was Englert, who was a Charter Member of the International Association of Bloodstain Pattern Analysts (IABPA). Englert was not able to travel to the crime scene, so he sent his photographer.

Police were unaware at the time that Stites was unqualified to render opinions about blood-stain analysis, but he did. Prior to traveling to Indiana, Stites had never taken any courses on bloodstain analysis or crime scene reconstruction, and was not a member of any blood stain analysis organization. The Indiana State Police evidence technician, who was initially in charge of processing the crime scene, had strong reservations about the so-called "expertise" of Robert Stites. After watching Stites the seasoned CSI realized that Stites didn't know what he was doing.

The CSI came to this realization after Stites claimed there was evidence of clean-up at the crime scene. He said there had been a clear watery substance added to the large volume of blood that flowed downward to the edge of the garage away from the wife's head wound. It turns out that it was serum separation, which helped provide a timeline as to when the murders happened. A defense bloodstain expert calculated that it would have taken about two hours for the serum to separate, placing the time of death at around 7:30 p.m. Stites arrived at the crime scene on Sept. 30, 2000. On the following day, David was arrested based on Stite's opinion that high velocity impact spatter was present on David's gray t-shirt known as Area 30. The police officer who served the arrest warrant, had reservations about arresting David based on the opinions of Stites.

The affidavit that prosecutors drafted that provided probable cause to arrest Camm relied entirely on the opinions of Stites. Stites observed eight small blood stains on the front left side of David's t-shirt that were less than one millimeter in diameter. The size of stains, he said, meant this had to have been high velocity impact spatter from being in close proximity to a fired gun.

Backspatter and forward spatter from a bullet penetrating a blood source at high velocity can project a fine mist pattern of blood stains; backward as the bullet penetrates the object and forward as the bullet exits. Blood stains from high velocity impact spatter typically are less than a millimeter in diameter, as is found on David's t-shirt.

However, as I learned from my BPA training, "Both expectorate blood [aspirated from the mouth] and flies produce patterns that an analyst can misidentify as impact spatter", according to Tom Bevel's book Bloodstain Pattern Analysis: with an Introduction to Crime Scene Analysis. Bevel cautions that it is, therefore, important for the analyst to consider the full context of the crime scene.

EXPERTS FOR THE DEFENSE
Blood stain experts Bart Epstein, Terry Laber, Stuart James, and Paul Kish, some of the most respected bloodstain experts in the country testified for the defense. They expressed their professional opinions that the small spots of blood on David's t-shirt were transfer stains caused by the t-shirt coming into contact with blood saturated strands of his daughter's hair.

However, none of the State's bloodstain experts reported observing high velocity impact spatter stains on David's shorts. The absence of spatter stains on David's pants adds strength to the conclusion that the stains on Area 30 were caused by transfer from the shirt coming into contact with his daughter's blood soaked strands of hair.

The linear pattern of the stains is also not consistent with high velocity impact spatter. One would expect to see a conical pattern of dispersal from high velocity impact spatter (both forward and back spatter) when a bullet fired from a gun impacts a body of blood. However, the bloodstains on Area 30 form a straight line, a pattern that is more consistent with a transfer of blood from strands of hair from a head wound.

MISUSE OF BPA IN AMERICAN COURTROOMS
My first case involving Rodney Englert, was a Lawrenceville, IL woman who was facing the death penalty. In June of 2000, I received a phone call from Katharine Liell, a criminal defense attorney from Bloomington, IN. Ironically; she would later represent David Camm. Her client, Julie Rea, was a Ph. D. student at Indiana University. It was a cold-case. Three years had gone by since the murder of Julie's son, 10 year-old Joel Kirkpatrick. On Oct. 13, 1997, at 4 a.m., Julie was awakened by her son's screams for help. When she went into his room, she startled an intruder. He had just stabbed her son to death with a knife that came from her kitchen.

The elected state's attorney resisted pressure from the sheriff and her ex-husband to place her under arrest. The prosecutor made a public statement that there was not enough evidence to arrest anyone. After he left office, a special prosecutor intent on charging Julie Rea with a capital offense was appointed to take charge of the investigation. The special prosecutor hired Rodney Englert.

Englert was able to see evidence of cast off bloodstains in his interpretation of the night-shirt Julie was wearing when she encountered the intruder. Englert opined that the cast-off stains were allegedly caused when the mother drew back the knife after repeatedly stabbing her son to death. Bloodstain interpretations previously made by forensic scientists from the Illinois State Police could only find transfer patterns consistent with the mother's story about colliding into an intruder and struggling with the man. She had a black eye where the man had punched her in the face, and she had a gash on her arm that required sutures.

I told Julie's attorney that if I was appointed to her client's case, I would want to investigate whether Tommy Lynn Sells had been in the area at the time of the murder. A child serial killer, Sells had just been arrested in Del Rio, TX, for a similar crime in which he broke into a trailer at 4 a.m and used a knife from the kitchen to kill Kaylene Harris while her mother slept. However, prosecutors decided not to seek the death penalty in a maneuver to avoid reforms that would have leveled the playing field by providing Julie's defense with financial resources to investigate her innocence prior to trial. After Julie was convicted in March of 2002, Diane Fanning published Through the Window: The Terrifying True Story of Cross-Country Killer Tommy Lynn Sells. Sells had told Fanning about a murder in Illinois in which he had killed a child and was startled by the mother who came into the room. He said he would have killed her too, if he hadn't dropped the knife. Crime scene investigators found the bloody knife on the floor at the doorway, where Julie said she encountered the man.

I was able to corroborate the confession with witnesses who reported to their sheriff an intruder who matched Sell's physical description. Based on this evidence, Texas Ranger John Allen provided an affidavit supporting Julie's petition seeking to overturn her conviction. However, after her conviction was overturned the same prosecutors and police investigators who got it wrong dug in their heels and decided to disbelieve the confession before consulting with Texas law enforcement authorities. They re-arrested Julie just as she was about to be released from prison and set her case for re-trial. A new jury, hearing the evidence of the serial killer's confession found her not guilty in 2006. She was represented by the Center on Wrongful Convictions at Northwestern University Law School pro bono. She subsequently received a Certificate of Innocence.

On June 2, 2003, a year after Englert's testimony was used to persuade juries to convict David Camm and Julie Rea, an ethics complaint against Englert was filed with the American Academy of Forensic Science by some of the most respected bloodstain experts in the country alleging that Englert had misrepresented his education, training and experience. Subsequent to this, Englert filed suit against Herb MacDonell (regarded as the father of the BPA profession) alleging slander for calling Englert among other things "a forensic whore", "liar-for-hire", "a very smooth charlatan", and "the Bin Laden of bloodstains".

In 2009, the National Academy of Sciences released a critique of forensic science practices in U.S. courtrooms, noting that since the introduction of DNA testing in 1989 that "faulty science" was found to be responsible for the wrongful convictions of a number of post-conviction DNA exonerations. BPA was one of several disciplines that were faulted because of the interjection of "examiner bias" that may lead to erroneous conclusions when interpreting evidence like bite marks, tool marks and bloodstains. The report noted "many sources of variability arise with the production of bloodstain patterns, and their interpretation is not nearly as straightforward as the process implies". The report found, "some experts extrapolate far beyond what can be supported", and went on to conclude that "extra care must be given to the way in which the analyses are presented in court. The uncertainties associated with bloodstain pattern analysis are enormous".

DNA IDENTIFIES CHARLES BONEY
Four years after David Camm was arrested, his conviction was reversed in Aug. 2004, because prosecutors had unfairly inflamed the jury by introducing testimony about his extramarital affairs. Some of his affairs were with women with whom he worked at the Indiana State Police Sellersburg Post, which had taken charge of the homicide investigation.

A new team of investigators were called into the case to be "fresh eyes". They discovered from their review of the file that there had been a grey sweatshirt that was foreign to the crime scene. The sweatshirt was found underneath Brad Camm's body, where his father laid his son next to his wife.

The inside collar had the moniker "BACK-BONE" written in black ink. At the very beginning of the investigation the collar had been swabbed by a forensic scientist to identify the wearer's DNA. An unknown male DNA profile was identified. Prior to David's first trial his defense attorney asked the prosecutor, Stan Faith, (who had charged David) whether this DNA profile had been entered into CODIS, the FBI offender DNA database. The prosecutor told the defense attorney that it was submitted, but there was no hit. This was a false representation, which obstructed justice for David Camm.

Years later, after an appellate court reversed David's conviction, Camm's new attorney, Katherine Liell, requested that the DNA be entered into CODIS. In Feb. 2005, a CODIS hit came back identifying a career criminal named Charles Darnell Boney whose prison nickname was BACK-BONE. He had been released from prison a few months before the Camm family was killed. Known as the "Shoe Bandit", Boney had a foot fetish and was sexually aroused by holding women at gunpoint and stealing their shoes.

One of the female troopers who arrived at the crime scene had noted in her report that it was odd that the shoes of David's wife had been removed from her feet and were placed on top of the vehicle.

Now, it all made sense.

Although his wife's shoes and pants had been removed, there was no evidence of a sexual assault in the conventional sense. So investigators dismissed the idea that the crime was motivated by the behavior of a sexual predator. But knowing Boney's sexual predilection of being aroused by women's bare feet and legs, the artifacts of the crime scene fit perfectly with his MO.

THE PROSECUTION COMPLEX
Chicago Sun Times reporter Tom Frisbie described the "Prosecution Complex" in his book Victims of Justice, about the infamous Nicarico case. Instead of seeking justice when new and exonerating evidence was found proving the innocence of Rolando Cruz, which included DNA and confession of a serial killer, the police and prosecutors who got it wrong tend to circle the wagons to fend off the attack on the original conviction. In that case, police and prosecutors were eventually indicted for a conspiracy to obstruct justice.

Less than a month after DNA identified Charles Boney, his palm print was found on the door frame of the passenger side of David's wife's Ford Bronco. This palm print is consistent with Boney having reached inside the vehicle to fire the shots that killed 7 year-old Brad, and his 5 year-old sister, Jill, who was still seat belted inside the vehicle.

Earlier, a judge had lowered David's bond. He was released to what remained of his family. His uncle, Sam Lockhart, who had been playing basketball that night with David, bonded him out of jail.

But now Boney was given a choice. He could be charged with the death penalty, or he could cooperate and assist prosecutors with their theory that Boney provided the gun to David Camm that he allegedly used to kill his family. Boney initially denied knowing David when he was interviewed in February. A month later, with this new and compelling evidence of his palm print, Boney's life depended on which choice he made. Despite his previous series of proven lies, Boney changed his story, and now said he met David playing basketball and after this first meeting arranged to sell him a gun that he wrapped in his sweatshirt. However, this does not explain why David's wife's DNA is on the left sleeve of the sweatshirt. The autopsy revealed that David's wife had struggled with the assailant and had injuries suggesting she had been choked.

Nevertheless, David was re-indicted for conspiracy to commit murder and has been confined to a prison cell ever since. Although Boney was convicted of conspiracy to commit murder and remains in prison, he recently said he has every expectation of being a free man someday.

EXONERATING THE INNOCENT
The highlight of my BPA training was the arrival of Tom Bevel. He had been on the road most of that week testifying in court. During the noon break after his presentation, he told me about his work on a case in North Carolina where he had provided testimony of his interpretation of bloodstain evidence that had helped to exonerate an innocent man

On Feb. 10, 2010, he provided testimony for the North Carolina Innocence Project before an independent panel of three judges. This special commission was created by the state's Supreme Court to establish an independent review of inmate claims of actual innocence called North Carolina Innocence Inquiry Commission, the first of its kind in the nation. Bevel's testimony persuaded the three judges that there was clear and convincing evidence demonstrating the innocence of Greg Taylor. Taylor was granted a full pardon on May 21, 2010, and was released from prison. He had been wrongfully convicted in 1993 of first degree murder based on erroneous testimony concerning bloodstain evidence. He spent nearly two decades in prison for a crime he did not commit.

A few years before that, Bevel had also assisted with the release of Tim Masters, an innocent man who had been convicted of murder in Colorado. In that case, Bevel reversed the previous opinion he had given that originally helped to convict Masters, after he had been provided additional evidence that had been concealed from him by the police detective who was later indicted for his alleged misconduct in the case.

Some of the real heroes in cases like this are guys like Tom Bevel, who dare to reveal their humanity by admitting when they get it wrong, but are willing to work to make it right.

( On October 24, 2013, David Camm, walked free after 13-years in prison after a jury in Lebanon, Indiana found him not guilty in a third re-trial. His case was the first exoneration for Investigating Innocence, which was started earlier that year. Bill Clutter, who started the project, was a member of Camm's defense team and suggested conducting an animated crime scene reconstruction, which helped persuade the jury that David Camm is innocent. Students at the University of Indiana assisted Clutter and the Camm defense team in reviewing the case and provided a fresh set of eyes. ( Read more about the exoneration here. )

Bill Clutter is a board certified member of the Criminal Defense Investigation Training Council. He started the Illinois Innocence Project in 2001, and is the Director of Investigations for a national innocence project called Investigating Innocence that he started in January 2013.

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Bloodstain Pattern Analysis: The Case of David Camm

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By: Bill Clutter The first use of blood stain analysis in an American courtroom occurred in 1966, in the re-trial of Sam Sheppard, an Ohio physician who spent over 10 years in prison before being freed. Sheppard had been convicted in 1954 of bludgeoning his wife to death in her bed, but maintained his innocence,...

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Telling different was to packaged blood and ways of shipping it.
D.Williams

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Section One: Collecting and Labeling Specimens

Required Specimens

Unless otherwise directed, collect the following specimens from each person who may have been exposed:

Whole blood

Collect blood specimens from adults only unless you receive specific instruction from CDC to collect blood from pediatric patients.

Collect a minimum of 12 mL of blood.

Use three 4-mL or larger vacuum-fill only (unopened), non-gel, purple-top (EDTA) tubes; use four tubes if using 3-mL tubes.

Using indelible ink, mark each purple-top tube of blood in the order collected (e.g., # 1, # 2, # 3, # 4 [if using 3-mL tubes]).

In addition, collect another specimen using one 3-mL or larger, vacuum-fill only (unopened), non-gel, green- or gray-top tube. Allow the tube to fill to its stated capacity.

Urine

Collect at least 40-60 mL from potentially exposed adults and children.

Use a screw-cap plastic container; do not overfill.

Freeze specimen as soon as possible (−70 °C or dry ice preferred).

If other than "clean catch", note method of collection on the specimen cup (e.g., obtained by catheterization).

Blanks

For each lot number of tubes and urine cups used for collection, provide the following to be used as blanks for measuring background contamination:

Two (2) empty, unopened purple-top tubes.

Two (2) empty, unopened green- or gray-top tubes.

Two (2) empty, unopened urine cups.

Labeling Specimens

Label specimens with labels generated by your facility and follow your facility's procedures for proper specimen labeling.

In addition to unique patient identifiers (e.g., medical records number, specimen identification number) labels should convey the collector's initials, date and time of collection so that law enforcement officials may trace the specimen to the collector should investigations lead to legal action and the collector has to testify that he or she collected the specimen.

If you use bar-coded labels, place the labels on blood tubes and urine cups so that when these containers are upright, the bar code looks like a ladder.

Maintain a list of names with corresponding specimen identification numbers at the collection site so that results can be reported to patients. It is recommended that you record additional data for use in the interpretation of results. Additional data may include: time of potential exposure, method of urine collection if other than "clean-catch", indication if sample was collected post-mortem, and antidotes administered prior to sample collection.

Information provided on labels and lists may prove helpful in correlating the results obtained from CDC's Rapid Toxic Screen and subsequent analysis with the people from whom the specimens were collected.

Section Two: Packaging Specimens

Packaging consists of the following components: primary receptacles (blood tubes or urine cups), secondary packaging (materials used to protect primary receptacles), and outer packaging (polystyrene foam-insulated, corrugated fiberboard shipper).

Secondary Packaging for Blood Tubes

To facilitate processing, package all blood tubes from the same patient together.

Place absorbent material between the blood tubes and the first layer of secondary packaging. Use adequate absorbent material to absorb the entire contents of the blood tubes.

Separate each tube of blood collected from other tubes to prevent tube-to-tube contact. The first layer of secondary packaging must be secured with one continuous strip of evidence tape and initialed half on the tape and half on the first layer of secondary packaging by the person making the seal. For example, one of the ways to do this is to-
Pack blood tubes in a gridded box lined with absorbent material. Seal the top half of the box to the bottom half with one continuous piece of evidence tape and write your initials half on the tape and half on the box.

Wrap and seal the first layer of secondary packaging (e.g., gridded box) with absorbent material.

Seal one wrapped gridded box or alternative container inside a clear, leak-proof biohazard polybag equivalent to Saf-T-Pak product STP-701, STP-711 or STP-731.

Place this bag inside a white Tyvek® outer envelope (or equivalent) and seal the opening with a continuous strip of evidence tape initialed half on the packaging and half on the evidence tape by the individual making the seal.

According to 49 CFR 173.199(b), if specimens are to be transported by air, either the primary receptacle or the secondary packaging used must be capable of withstanding, without leaking, an internal pressure producing a pressure differential of not less than 95 kPa (0.95 bar, 14 psi). Verify in advance that the manufacturer of either the blood tube or secondary packaging used in your facility is in compliance with the pressure differential requirement.

Outer Packaging for Blood Tubes

Use polystyrene foam-insulated, corrugated fiberboard shipper (may be available from your transfusion service or send-outs department).

For cushioning, place additional absorbent material in the bottom of the shipper.

Add a single layer of refrigerator packs on top of absorbent material.

Place the packaged specimens on top of the refrigerator packs.

Use additional cushioning material to minimize shifting while the shipper is in transit.

Place additional refrigerator packs on top of the secondary packaging to maintain a shipping temperature of 1 °C - 10 °C

Place blood shipping manifest in a sealable plastic bag and put on top of packs inside the shipper. Place lid on the shipper.

Keep chain-of-custody documents for your files.

Place your return address in the upper left-hand corner of the shipper top and put CDC's receiving address in center.

Affix labels and markings adjacent to the shipper's/consignee's address that appears on the shipper.

Place the UN 3373 label and the words "Biological Substance, Category B" adjacent to the label on the front of the shipper.

Secondary Packaging for Urine Cups

Separate each urine cup from other urine cups to prevent contact between urine cups. The first layer of secondary packaging must be secured with one continuous strip of evidence tape and initialed half on the tape and half on the first layer of secondary packaging by the person making the seal. For example, one of the ways to do this is to-
Pack urine cups in a gridded box lined with absorbent material. Seal the top half of the box to the bottom half with one continuous piece of evidence tape and write your initials half on the tape and half on the box.

Place urine cups, boxed and secured properly with evidence tape, in the next layer of secondary packaging. An example of acceptable material is the Saf-T-Pak Disposable 2-Part Pressure Vessel system or its equivalent.

Secondary packaging must have its closure secured with a single strip of evidence tape initialed half on the packaging and half on the evidence tape by the person making the seal.

Outer Packaging for Urine Cups

Use polystyrene foam-insulated, corrugated fiberboard shipper (may be available from your transfusion service or send-outs department).

For cushioning, place additional absorbent material in the bottom of the shipper.

Place a layer of dry ice on top of the absorbent material. Do not use flakes or large chunks of dry ice for shipment because large chunks have the potential for shattering urine cups during transport.

Ensure that specimens will remain frozen or will freeze during transport.

Place packaged urine cups in the shipper.

Use additional absorbent or cushioning material between wrapped urine cups to minimize shifting while shipper is in transit.

Place an additional layer of dry ice on top of samples.

Place the urine shipping manifest in a sealable plastic bag and put on top of dry ice inside the shipper. Place lid on the shipper.

Keep chain-of-custody documents for your files.

Place your return address in the upper left-hand corner of the shipper top and put CDC's receiving address in center.

Place the UN 3373 label and the words "Biological Substance, Category B" adjacent to the label on the front of the shipper.

Place a Class 9/UN 1845 hazard label on the same side of the shipper as the UN 3373 marking.

If the proper shipping name, (either dry ice or carbon dioxide, solid) and Class 9/UN 1845 is not preprinted on the hazard label, add it in an area adjacent to the label.

Note the weight of dry ice (in kg) on the preprinted area of the hazard label, or place that information adjacent to the Class 9/UN 1845 hazard label.

Orientation arrows are not required on a shipper containing "Biological substance, category B." If you use arrows, be sure to orient the inner packaging so that closures are aligned with the arrows.

If the shipper will be transported by a commercial air carrier, complete an airway bill. On the airway bill, note the proper shipping name and UN number for each hazardous material and identify a person responsible for the shipper per IATA packing instruction 650.

Section Three: Shipping Specimens

Follow the guidance provided in your state's chemical exposure comprehensive response plan. If you are directed to ship the specimens to CDC, please ship the specimens to the following address:
Centers for Disease Control and Prevention
CDC Warehouse
3719 N. Peachtree Rd.
Chamblee, GA 30341
ATTN: Chariety Sapp - (770) 488-0343
Preparing Documentation

Since blood tubes and urine cups cannot be shipped together in the same package, prepare a separate shipping manifest for each.

Note on shipping manifest if urine sample is collected by means other than clean catch (e.g., catheterization).

Place each shipping manifest (with specimen identification numbers) in a plastic zippered bag on top of the specimens before closing the lid of the polystyrene foam-insulated, corrugated fiberboard shipper.

Do not transport chain-of-custody forms with specimens. Each entity or organization handling the specimens is responsible for the specimens only during the time that it has control of the specimens.

Each entity or organization receiving the specimens must sign-off on the chain-of-custody form of the entity or organization relinquishing the specimens to close that chain. Electronic procedures such as electronic chain-of-custody and barcode readers will expedite this process.

When receiving specimens, each new entity or organization must begin its own chain of custody. The entity or organization relinquishing the specimens must sign its chain of custody to close the chain and indicate that they have transferred the specimens.

Note: When the person relinquishing the specimens (relinquisher) and the person receiving the specimens (receiver) are not together at the time of specimen transfer, the relinquisher must document on its chain-of-custody form that the receiver is the express courier (e.g., FedEx, Delta Dash, DHL, UPS) and must document the shipment tracking number or have the person transporting the specimens sign the chain-of-custody to indicate that he or she has taken control of the specimens. Likewise, when receivers get the specimens, they will document on their chain-of-custody form that the relinquisher is the express courier (and provide the tracking number) or have the person transporting the specimens sign the chain-of-custody form.

Questions

For questions concerning these instructions, please contact:
Centers for Disease Control and Prevention
Attn: Chariety Sapp
(770) 488-0343

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centers for disease control and prevention

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Unless otherwise directed, collect the following specimens from each person who may have been exposed: Whole blood Collect blood specimens from adults only unless you receive specific instruction from CDC to collect blood from pediatric patients. Collect a minimum of 12 mL of blood.

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This talks about the DNA and the information it carries with it along with it, including blood.
-A. Grayer

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The FDLE DNA Database receives DNA samples from individuals arrested or convicted for offenses as mandated under 943.325, Florida Statutes, including, but not limited to, sexual assault, lewdness/indecent exposure, murder, robberies, kidnapping, assault/battery, burglary, felony firearm violations, and thefts. Multiple agencies share the responsibility of collecting DNA samples from qualifying offenders, including the Florida Department of Corrections, Department of Juvenile Justice, Sheriff's Offices and those in charge of the county correctional facility. The law requires individuals to submit a DNA sample to the DNA Database for analysis allowing for the comparison of DNA from unresolved cases to the DNA of both known offenders and that from other unresolved cases in an attempt to identify the perpetrator. Florida Administrative Code 11D-6 supplies definitions and procedures for sample collection. The Florida DNA Database averages over 4,500 DNA hits to unsolved crimes per year.

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The FDLE DNA Database receives DNA samples from individuals arrested or convicted for offenses as mandated under 943.325, Florida Statutes, including, but not limited to, sexual assault, lewdness/indecent exposure, murder, robberies, kidnapping, assault/battery, burglary, felony firearm violations, and thefts.

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Gives how liquid and dried blood are collected at a crime scene.

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D.Williams

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The collection and preservation of blood stain evidence is important because this evidence can be used to type blood or run DNA analysis.

There are two different types of blood that can be collected at a crime scene: liquid and dried blood. Liquid blood evidence is generally collected from blood pools but can be collected off of clothing as well, using a gauze pad or a sterile cotton cloth. Once the sample is collected it must be refrigerated or frozen and brought to the laboratory as quickly as possible. The sample must first be dried thoroughly at room temperature. It is important to get the sample to the laboratory as quickly as possible because after 48 hours the sample might be useless. If the sample has to be mailed it should be completely air dried before packaging. If the sample isn't completely dry when it needs to be packaged, the sample should be rolled in paper and labeled and then put into either a brown paper bag or a box. The paper bag or box is then sealed and labeled again. It is important to only place one item per container to avoid contamination and samples should not be placed in plastic containers. Samples shouldn't be in plastic containers because if the sample is still damp the moisture from the sample can cause microorganisms that can destroy the evidence. Also, due to this fact, samples should not be in any container for more than two hours.

Dried bloodstains can be found on small objects, larger objects and on clothing. When dried blood is found on a small object the entire object can be sent to the lab after it's been properly packaged and labeled. When dried blood is found on a larger object that is transportable, an investigator should cover the stained area with paper and tape the paper to the object to avoid contamination. If the object that is stained is not transportable there are different ways that an investigator can collect the sample. One option is to cut out the stained area of the large object. If the portion is cut out the sample is packaged the same way as described above but a control sample should also be provided in a separate package. Another option is to use fingerprint tape and lift the sample as well as the surrounding control area. If this method is used it is important for investigators to not touch the sticky side of the tape with bare hands and the investigator should run an eraser or some type of blunt object over the placed tape to ensure that contact is made with the dried stain. The lifted stain is then be packaged and labeled, then delivered to the laboratory. Another way to collect a sample off of an object is to use a clean sharp object to scrape flakes of the stain into a paper packet. The last two methods of collection of a dried bloodstain on a large object require the use of distilled water to dampen the stain before rolling a thread in the stain or absorbing the stain with a cotton square. These two methods are not recommended due to the risk of contamination. When dried blood is found on clothing the entire article of clothing should be packaged and labeled and delivered to the lab.

It is important for the investigator to remember to keep each sample separated so that there is no contamination between samples.

Back to Crime Library

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Blood Evidence: Collection and Preservation - Crime Museum

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The collection and preservation of blood stain evidence is important because this evidence can be used to type blood or run DNA analysis. There are two different types of blood that can be collected at a crime scene: liquid and dried blood.

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This Case involved the bloodstains that matched up to the perpetrator's flashlight as well as the same gun that he owns
-A. Grayer

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Recent testimony from an evidentiary hearing in the Joe Bryan case in Texas has centered on blood spatter interpretation. Bryan was a school principal who has been serving a 99-year prison sentence for the 1985 murder of his wife. His conviction was based in part on the testimony of an expert witness in blood spatter interpretation.

The blood spatter testimony indicated that the weapon used was a .357, like the one that Bryan owned. The prosecution stated that a flashlight found in Bryan's car days after the murder contained small drops of the victim's blood, although only presumptive tests were conducted. The blood spatter analyst testified the killer held the flashlight as he shot from close range.

Bryan continues to assert his innocence and an evidentiary hearing was held last month in which his attorney argued - backed by the testimony of a crime scene investigator - that the blood spatter testimony presented at trial was scientifically unsubstantiated. The hearing is currently in recess, awaiting the results of DNA testing on the flashlight that are expected to come back sometime in the fall.

In May, Pamela Collof published a two-part article describing in-depth the background of the case and the testimony of the blood spatter expert witness. The articles are available at: https://features.propublica.org/blood-spatter/mickey-bryan-murder-blood-spatter-forensic-evidence/ (Part I) and https://features.propublica.org/blood-spatter/joe-bryan-conviction-blood-spatter-forensic-evidence/ (Part II).

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Recent testimony from an evidentiary hearing in the Joe Bryan case in Texas has centered on blood spatter interpretation. Bryan was a school principal who has been serving a 99-year prison sentence for the 1985 murder of his wife. His conviction was based in part on the testimony of an expert witness in blood spatter interpretation.

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A close up of a bloody handprinted on the ground
-A. Grayer

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Ways of how blood will be measure from your DNA
D.Williams

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Starting in October 2016, FDDU began to issue a new and smaller oral DNA collection device. This new collector allows for a direct transfer from inside the cheek onto collection paper in a similar manner to the current collection device, and allows for the possibility of self-collection by offenders. Detailed instructions for its use is included in the kits, and the FD-936 form has not changed. FDDU will continue to accept the old kits, so please use all the current kits in your inventory before ordering new kits.

What We Do

The Federal DNA Database Unit (FDDU) serves the greater forensic community by aiding investigations through hit confirmations against individuals whose profiles are in the National DNA Index System (NDIS). Agencies submit blood or buccal samples to the unit from individuals who are required by law to do so. These include individuals convicted of, arrested for, or facing charges of certain qualifying federal crimes or convicted of qualifying District of Columbia offenses, as well as non-U.S. citizens who are detained under the authority of the United States. FDDU then produces a DNA profile for each of these individuals and uploads it to the NDIS, which is part of the Combined DNA Index System (CODIS).

These known DNA profiles are then searched against unknown forensic profiles from crime scenes across the country. If a match is identified, the casework laboratory can request FDDU to confirm the offender sample DNA profile. Once the profile is confirmed, the FDDU will then release the subject's personal identifying information back to the casework laboratory. This information can then be passed on to investigators in the hopes of apprehending the perpetrator. Thanks to law enforcement agencies and their sample submissions, FDDU has uploaded over one million profiles to NDIS and has aided thousands of investigations to date.

Under the overall direction of the FDDU chief, unit operations effectively cascade across two supervisors and are guided by their respective management of integral program teams. A team of accessioning scientists handle the initial triage of submissions into the unit, inventorying samples, inputting specimen data, and preparing specimens for the beginning stages of testing. A team of laboratory scientists apply robotic processing stations and high-throughput instrumentation to generate DNA typing results from samples within days of sample acceptance. A team of reporting scientists interprets the resulting DNA profiles, approve data for upload, and author correspondence to casework laboratories regarding database associations confirmed between FDDU specimen DNA profiles and corresponding evidentiary DNA profiles.

On a compliance level, the FDDU is supported by teams of DNA technical specialists and DNA program specialists, who have critical responsibilities within the unit for ensuring the quality assurance and quality control of analytical testing, as well as conformance of database operations with established procedural requirements.

Administratively, the unit is supported by a team of management and program analysts with responsibilities for budgetary execution, procurement, inventory, and logistical applications. The unit relies heavily upon an information technology team to support the unit network and overall infrastructure backbone that drives the various operational applications.

From a technology perspective, a DNA Laboratory Information Management System (LIMS) is critical for the automated development of specimen works lists, controlling the stepwise progression of each sample through the entire analytical process. The FDDU utilizes robotic systems in the laboratory to achieve high-throughput processing, allowing for a day-through-evening uninterrupted workflow without human intervention, permitting maximum operational efficiency. A sophisticated software analysis tool (expert system) permits an automated review of resulting DNA data with a reduced level of scientist intervention, increasing throughput rate while consistently meeting or exceeding required performance measures.

History of the Unit and Legislation

FDDU was initially established in 2000 as the Federal Convicted Offender (FCO) Program as a result of the DNA Backlog Elimination Act. Expanding DNA legislation over the next decade significantly impacted both the scope and direction of the FCO Program, which began overseeing the uploading of DNA profiles into NDIS in 2002 and became its own unit, FDDU, in 2009. By July 2015, the unit uploaded its one millionth sample to NDIS.
Read more about major milestones in the history of FDDU and the legislation directing the unit's mission.

DNA Kit Collection Instructions

The current Bode Buccal Collection Kit, released October 1, 2016, and previous kits can be submitted to FDDU by following the instructions in the respective links. The letters "B", "C", "D", and "E" referenced for the kit will be the first character of the kit barcode printed on the main kit envelope:

The Federal DNA Database has created an instructional DVD video available for training and education about our unit and DNA collection kits. These DVDs are available for official law enforcement and other federal collection agencies only. They are free of charge; please email us at fddu@ic.fbi.gov if you would like to place an order.

Contact Information

For further information, please contact FDDU by e-mail at fddu@ic.fbi.gov, or alternatively:

By phone - (703) 632-7529

By fax - (703) 632-7620

By mail - Federal DNA Database Unit, 2501 Investigation Parkway, Quantico, VA 22135

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The Federal DNA Database Unit analyzes the Core CODIS loci DNA markers from buccal and blood samples of federal convicted offenders, arrestees facing federal charges, individuals convicted of certain District of Columbia offenses, and non-U.S. citizens detained under the authority of the U.S., for development of DNA profiles that are uploaded to the National DNA Index System (NDIS).

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This case is about how bloodstain pattern analysis is carried out.
D.Williams

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On 29th March, 2001. Robert Perry, an 83 year old who had been suffering with terminal throat cancer, was found dead in his mobile home. His 57 year old nephew, Craig Perry and Carol, Craig's girlfriend called in the 'suicide'.

Blood spatter analyst's determined that suicide seemed unlikely: Blood was coming from the back of Roberts head (a very awkward place to shoot yourself) and a .22 caliber pistol was laying at his feet. They also noted that Craig had some of Roberts blood on his pants. Craig claimed that this was from embracing his dead uncle, however the pattern was not consistent with this claim. The blood was a high velocity pattern which is consistent with a gunshot wound.

This was evidence enough to warrant a few questions to be answered. When questioned about the incidence Craig and Carol's stories seemed to differ in area's.

More Blood spatter analysis came in to rule out suicide. If Robert had killed himself while slumped on the end of the bed, as Craig and Carol had reported to finding him, he would have blood stains on his legs. However there was none.

They determined that Robert must have been shot while sat on the floor, leaning on the bed, the blood on the side of the sheets showed this. They also determined that the blood on Robert's hand was from contact with the blood on the floor. There was no fine spray on his hands as would be expected with a self-inflicted gunshot wound. The pistol was never tested for fingerprints.

The story continued to unveil as evidence of a second shot being fired was found. A surgical pathologist, George Lindholm was brought in to confirm that Robert could have fired two shot before dying, however this would have been unlikely. At this point Craig and Carol were highly likely suspects, but suicide had not been ruled out just yet.

More blood work was done, this time by a blood spatter pattern expert, James, on behalf of the defense team. He had doubts as to whether Craig was the killer. James said that the blood on Craig's pants could have been coughed up by Robert earlier in the day.

Ultimately Craig was acquitted of the murder case as there was reasonable doubt and he had no motive for murder.

There was no doubt however that the Bloodstain pattern analysis played a massive part in the investigation both for and against the murder theory. With the help of blood spatter analysts, Robert's position at the time of the gunshot and the way in which Robert was shot was determined. If the gun was fingerprinted; more light could have been shed on the true story.

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On 29th March, 2001. Robert Perry, an 83 year old who had been suffering with terminal throat cancer, was found dead in his mobile home. His 57 year old nephew, Craig Perry and Carol, Craig's girlfriend called in the 'suicide'.