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Biological Evidence - Hair - Crime Museum

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Often, hair is picked up at a crime scene and used as contributing biological evidence in a case. This can be helpful in determining the perpetrator of a crime and in providing more information about what actually took place. When gathering a hair sample, it is better to have a larger sample of hair rather...

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renardo bonner

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Hair is a tough protein filament that grows form follicles which are present in the junction between the deep layers of the dermis and the hypodermis. Protein from which hairs are made of named as alpha keratin. In hair follicles, living cell divide and grows to hair shaft. Hair is made up of 95% keratin which is synthesized by keratinocytes and is insoluble in water, it ensures impermeability and protection for the hair strands.

Hair is a type of trace evidence which easily found on crime scene, and it helps in establishment of link between suspects which are supposed to have link with crime and victim. The average hair sample submitted as evidence ranges from 24 to 50 strands. Hair sample is always considered as associate evidence.
Types of Human Hair:
◾ Lanugo - Soft hairs which grows all over the body. Fetuses have lanugo hairs at the end of pregnancy, and they lose their hairs within a 1-2 week.

◾ Vellus - Short, light-colored hairs which develops during childhood and barely noticeable. Have no sebaceous gland.

◾ Terminal - Thick, pigmented androgenic hair present on the scalp, face, armpits and pubic area.

A.) Hair Shaft- that part of hair which is above the scalp and made of toughened protein called keratin. These pigments are held together by two kinds of bonds- hydrogen bonds and disulphide bonds. It made up of three layers- cuticle, cortex, and medulla.
Hair consists of two different parts:
Cuticle- is the translucent outermost protective layer of hair which is made of dead cells called as keratin. It has cells shaped like scales of different types from root end to tip end of hair.
Pattern of scales present in cuticle are:
✔ Coronal - hair which have crown shaped scales. Mainly found in dogs, bats, rodents etc.

✔ Spinous - hair which have petal like scales, found in cat

✔ Imbricate - hair which have flattened scales, mainly found in humans.

Cortex- present between cuticle and medulla. It consists of pigment known as melanin which gives natural color to hair strands. It also contains long keratin chains that add elasticity, suppleness and resistance to the hair.

The amount of a pigment called melanin in hair determines hair colour. People with black or brown hair have an abundance of one type of melanin called eumelanin. People with red hair have an abundance of another pigment called pheomelanin.

Eumelanin gives brown or black color to hair strands and pheomelanin gives red color to hair strands. Color distribution in human hair strands is towards cuticle and in animals towards centre.

A condition in which white patches in the hair due to lack or less of melanin is said as Poliosis or Poliosis Circumscripta or White forelock.

is innermost layer of cells, and it is only present in thicker hair types. In humans, medulla diameter is less than 1/3rd of overall diameter of hair shaft. Medulla is of five types on basis of appearance- continuous, fragmented, interrupted, solid and absent.

B.) Hair Follicle- it is small and tunnel-shaped structure in epidermis of scalp and from its bottom end hair starts growing. The only 'living' portion of hair is found in the follicles. These follicles are known as hair bulbs. The average human has about 100,000 follicles on the scalp alone.
The shape of follicles determines the shape of the cortex and shape of hairs. Hair follicles are attached with sebaceous glands and arrector pili muscle. Three main parts of hair follicles which are found on the head: the infundibulum, the isthmus and the inferior segment which includes the hair bulb.

Infundibulum segment is the upper portion of the follicles which begins at the epidermis surface and extends to the opening of the sebaceous duct. The isthmus is the area between the sebaceous duct opening and the bulge and bulge is the part of follicle which are attached with arrector pili muscle and contains several epidermal stem cells. The inferior segment of the hair follicle extends from the bulge part to the base of the follicle.
Three different growth phase of hair follicles are:
⭕ Anagen Phase- it is a proliferation phase which occurs when the hair follicle is growing a new hair shaft. The only phase during which the inferior segment of the hair follicle is present.

⭕ Catagen Phase- also said as regression phase or transition phase which is the shortest phase. During this phase, cell division ceases and hair follicles begins to regress. Time period is of about two weeks.

⭕ Telogen Phase- it is resting or shedding phase. Follicles remain dormant for 1-4 month.

Hair samples found at crime scene are examined to identify its species, race, place of origin parts of body etc. firstly it is important to collect hair samples very carefully and sent them to forensic laboratories by following proper chain of custody.
Collection of Hair Sample:
🔸️ Collected using forceps carefully and packed into cellophane or paper bag.

🔸️ Samples can be tape lifted using adhesive tapes.
Determination of Species of Origin: Also Read: General Characteristics of Human Hair Determination of Origin of Race: Also Read: Morphological Characteristics of Human Hair for Racial Determination
Determination of Somatic Origin:

It means to identify hair sample belong to which part of species. Somatic origin type may include scalp, eyebrow, face, limb, pubic etc. origin can be identified by considering features such as length, shaft configuration, medullary configuration, cross-sectional shape, texture, tapering and appearance of the root.
Also Read: General Characteristics of Human Hair from Different Sites
Macroscopic Features of Hair:

The Macroscopic Features that can be observed in the hair are:

🔘 Color- White, red, brown, black, and other.

🔘 Hair Pattern- Straight, wavy, curly, kinky.

🔘 Diameter- fine, medium, coarse, variations.

Microscopic Features of Hair:

The Microscopic Features that can be observed in the hair are:

🔘 Color- Natural/treated color of hair.

🔘 Pigmentation- Distribution, Aggregation (density, size), granule (colour, size, shape, destiny)

🔘 Structure- diameter, shape (cross-section, configurations), root shaft[cortex, cuticle, medulla], Tip.

🔘 Hair Follicle- condition of the root area to determine whether the hair was taken forcibly and shed naturally.

Examination Of Hair

Temporary Mount- Mount of the hair strand sample is made on a clean slide using glycerin and covered with a coverslip. The morphological structures of the hair are observed under a microscope and note down hair shaft (cuticle, cortex and medulla) characteristics of the strand.

Scale Casting- A thin coat is painted on a clean slide and the hair to be cast is placed on the slide and allowed to dry. When the surface has dried, the hair is removed to observe the scale pattern.

Polaroid Coater Method- The hair sample strand is placed on a clean slide and the ends of the strand are secured with cellophane tape. A polaroid film coaster is applied 2-3 times along the length of the hair. This coating is allowed to dry for 23-24 hours. The excess coating that protrudes above the flat surface of the cast is sliced and then hair strand is gently peeled by removing cellophane tape. Now, the impressions of the scales can be microscopically observed.

Cross Sectioning- The hair sample is placed in a solution of ether and ethanol in the ratio 1:1. The samples are bundled and dipped in a block of molten wax and is then allowed to cool. Cross-sections can either be taken using a sharp blade or with a microtone to a thickness of 5-10μ. These sections are placed on a clean slide and the wax is dissolved with a drop of xylene. A permanent mount of the sections is prepared and then examined under a microscope.

Age and Sex Determination:

Generally, age cannot be determined by microscopic examination of hair samples, but it helps to differentiate between an infant and an adult individual by examining hair strands.

Sex can be determined from hair follicles which are attached with hair shaft and comes out with hair strand only when hair is pulled out forcibly. Sex determination can be determined through staining of sex chromatin in the nuclei of the cells showing the female indicative of the Barr body (bright spot, top) and male indicative Y body (bright spot, bottom).
Aceto-carmine stain is used for detection of - X bodies in hair, Barr- bodies in hair, Y bodies in hair.

DNA in hair is usually extracted from the root bulb. If a violent crime has taken place as hair could have been forcefully uprooted by both the victim and the perpetrator during a physical struggle. The DNA portion is extracted, amplified and the obtained sequence is run through a criminal database.

Both microscopic and DNA examination helps to narrow down who have been involved in a crime. In cases of mitochondrial DNA examination, it helps to solve the questions are raised related to evolution and inheritance. Hair also provides the information related to the toxic substance or any drug that may have been linked to health or problems in psychological, reproductive disorders and in developmental toxins.

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age and sex determination with the help of hair

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polaroid coater method for hair examination

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what method are used for hair examination in forensic science

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Hair (As an associate Evidence) - Forensic's blog

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Hair is a tough protein filament that grows form follicles which are present in the junction between the deep layers of the dermis and the hypodermis. Protein from which hairs are made of named as alpha keratin. In hair follicles, living cell divide and grows to hair shaft.

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renardo bonner

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Alonzo Allen

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December 30, 2018 By: Charlotte Anne Cox

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The Importance of Hair Evidence in Forensics

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Hair evidence can be an important element in solving crimes because it can put a victim and suspect together at a crime scene. Hairs can be transferred directly or from one person to another, or through indirect means.

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Alonzo Allen

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How To Package Hair At A Crime Scene? –
renardobonner

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Hairs are among the most commonly transferred trace evidence. They can be of considerable evidentiary value in linking individuals to crime scenes.

To collect hairs from a substrate, use the following procedure:

1. To collect visible hairs, use properly cleaned or disposable tweezers and carefully pick the hair off the substrate. Take care not to crush or break the hair when removing it. Place the recovered hair on a clean sheet of paper or Post-it® note (Post-it notes are useful for collecting hairs as the hairs are lightly held by the adhesive), taking care not to crease the hair in the fold. Place the folded paper into a properly labeled envelope (case number, date, exhibit number, a brief description, and your name).

2. Other ways of collecting questioned hairs (particularly if the hairs are not visible) from surfaces can be by tape-lifting or vacuuming.

1. To tape-lift an item, using clear packing or book tape, make a tape lifter by wrapping the tape back on itself around the tape roll, sticky side out. Roll the tape on the item until you have covered the entire object. If the tape gets too full of debris, use a second piece of tape. Cut the tape off of the roll and lay it, sticky side down, on a clean piece of clear plastic or sheet protector. The sheet protector or plastic sheet can be placed in a properly labeled envelope or container.

2. To vacuum an item, obtain a filter unit (which can be obtained from evidence collection suppliers) that attaches onto the nozzle of a vacuum hose. Proceed to vacuum the item and, when complete, preserve the filter (with the trace evidence on it) in an appropriate and properly labeled container.

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If an item will also be examined for ignitable liquid residue, please consult the laboratory for the proper collection procedure. Items should not be air-dried or packaged in an air-permeable container if they will be examined for ignitable liquid residue.

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Head and pubic hairs are generally the only human hairs that can be compared to known hairs. However, beard hairs may be suitable for comparison (check with your laboratory). When collecting known hairs for comparison, it is recommended that 25 pulled hairs and 25 combed/naturally shed hairs from various areas of the head (and beard, if present) or pubic region be collected.

To collect pulled hairs, be sure to wear new, unused, clean latex or nitrile gloves and pull 25 hairs (or have the suspect or person of interest do it themselves) from various areas of the scalp or pubic region. Place these in an evidence or pharmacy fold, place the fold in an envelope and properly label.

To collect combed or naturally shed hairs, you or the suspect (or person of interest) should take a clean, unused comb and comb their hair over a piece of clean paper. Fold the paper and the comb together and place it in a properly labeled envelope.

A buccal swab from the suspect or person of interest should also be submitted.

Some laboratories may also perform comparisons on animal hairs (check with your laboratory).

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Laboratory testing of hair:

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Source:

Crime Scene and Evidence Collection Handbook. Bureau of Alcohol, Tobacco, Firearms and Explosives, 2005.

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Hairs are among the most commonly transferred trace evidence. They can be of considerable evidentiary value in linking individuals to crime scenes. To collect hairs from a substrate, use the following procedure: To collect visible hairs, use properly cleaned or disposable tweezers and carefully pick the hair off the substrate.

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https://www.leicestershirevillages.com/how-is-hair-evidence-collected-at-a-crime-scene/

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A window is broken. A home is burglarized. Investigators identify a suspect and find a sliver of what appears to be glass embedded in his shoe. In the forensics lab, examiners determine, using advanced microscopy and chemical analysis, that the characteristics of that sliver match those of the broken glass in the burgled home.

Pretty strong evidence, right?

Not so fast, says Shannan Williams, who manages the trace evidence research program at the National Institute of Standards and Technology (NIST). "If those characteristics are common, that sliver of glass might match half the windows in town. But if they're rare, the evidence can be extremely powerful."

That's why one of the most important tools available to trace evidence examiners is not a microscope or a chemical reagent, but a database. Besides glass, trace evidence includes hair and fibers, fire debris, metal, paint, adhesives, and explosives, to name just a few. Large databases that describe these materials-and the variability among them-make individual pieces of trace evidence far more powerful than they would be alone.

Unfortunately, much data on trace evidence is scattered in databases at forensic labs and research departments where they are unavailable to the wider forensic community. But Williams and many others are working to change that.

Many of those individuals attended a workshop at NIST on July 19-20, 2016, where experts discussed trace evidence databases and the steps needed to make them more useful and widely available.

During his presentation, Claude Roux of the Centre for Forensic Science at the University of Technology in Sydney, Australia, said that trace evidence faces an uncertain future as an investigative tool, in part because, unlike DNA evidence, it does not have the power to directly identify suspects. Roux argued that this emphasis on identification can lead people to undervalue trace evidence, which can be used to generate leads, eliminate suspects, reconstruct sequences of events, and identify links in serial crimes.

Sandra Koch, who sits on the Materials Subcommittee of the Organization of Scientific Area Committees for Forensic Science, presented findings that also pointed to an uncertain future for trace evidence. Koch surveyed trace evidence lab managers, with many reporting that trace evidence is often perceived as a "junk science" with little or no value. An increasing number also face shrinking budgets.

In the face of these uncertainties, workshop participants discussed ways to increase the power of trace evidence through expanded access to trace evidence databases. In addition, experts from NIST, the Federal Bureau of Investigation, and the National Institute of Justice gave presentations on databases that their agencies make available to the forensic science community.

Workshop participants also discussed ways to make other trace evidence databases and collections-many compiled by individual forensic laboratories during years of casework, others created by manufacturing companies-more widely accessible to the forensic community.

Williams hopes that these efforts will help ensure that trace evidence remains a vital tool for crime fighters. "Trace evidence databases are force multipliers," Williams said. "They make every lab that uses them more effective."

Information about the Trace Evidence Workshop, including video and downloadable presentations, can be found here.

Stay tuned for other outputs from the conference, which over the next several months will include a roadmap for prioritizing data expansion efforts for specific trace evidence types, and a "database of databases" that will list over 500 publicly available, online databases relevant to forensic investigations.

If you are interested in participating and learning more about follow-on projects, .

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Trace Evidence Databases: A Force Multiplier for Forensic Investigators

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A window is broken. A home is burglarized. Investigators identify a suspect and find a sliver of what appears to be glass embedded in his shoe. In the forensics lab, examiners determine, using advanced microscopy and chemical analysis, that the characteristics of that sliver match those of the broken glass in the burgled home.

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With 20 strands of hair, a cap, a gun and a bullet fragment from the head of Ennis Cosby, the prosecution crossed a major hurdle Wednesday--tying 19-year-old Mikail Markhasev to the killing of the son of entertainer Bill Cosby.

But reminiscent of the O.J. Simpson murder trial, the Los Angeles Police Department's handling of the evidence came under attack, and Deputy Alternate Public Defender Henry Hall opened a mystery about a missing hair. He also hinted that the prosecution deliberately withheld the most important hair evidence from him and submitted it to destructive DNA analysis before he could conduct his own tests.

If Hall raises enough questions about the hair, it could seriously weaken the prosecution's efforts to use physical evidence to show that Markhasev killed Cosby in a failed robbery attempt Jan. 16, 1997, on a side road off the San Diego Freeway.

Physical evidence is especially important in this case. Deputy Dist. Atty. Anne Ingalls is relying heavily on testimony from witnesses whose criminal past and pending charges raise questions about their credibility. They are expected to say Markhasev admitted killing Cosby.

Hall is trying to show that one of those witnesses--Eli Zakaria, 24, who was with Markhasev on the night of the killing--is the probable murderer.

The hair came from a dark blue knit cap that was wrapped around a .38-caliber Taurus revolver that prosecutors say Markhasev, Zakaria and his girlfriend ditched in a wooded area in the San Fernando Valley shortly after Markhasev used it to kill Cosby.

Diana Paul, a Los Angeles Police Department criminalist, said Wednesday she test-fired the gun and compared the bullet with the bullet fragment that was removed from Cosby's head by the coroner. She first held up the fragment for the jury and then the pistol with its cylinder opened.

"The bullet was fired from this Taurus revolver," she said, looking directly at the jury.

Other witnesses Wednesday discussed the hair that came from the cap wrapped around the revolver.

Harry Klann, the lead criminalist in the case, said his analysis of a single strand that police say was extracted from the cap contained DNA that was virtually impossible for anyone other than Markhasev to have.

"It would exclude 99.9% of the population," he said.

Criminalist Susan Brockbank said that several hairs from the cap were similar to Markhasev's hair in color, distribution of pigment granules, condition of the root and other characteristics.

"All of the head hair from the cap were similar microscopically to the head hair sample [from Markhasev] and could have originated from him," she said.

But in a long, tedious cross-examination that started Tuesday, Hall tried to raise doubts that the hair matched Markhasev's.

Out of 20 strands of hair, only one was sufficient for DNA analysis, he said. That single strand seemed to surface late in the investigation and then was hidden from defense attorneys until the start of the trial, Hall said.

The Police Department's report on the hair comparison was not written until June 1, the day jury selection started for the trial.

When Brockbank examined the 20 hairs in March 1997 under a microscope, she said none of the hairs had the required "tissue material" around the root that made it suitable for DNA analysis. Even so, Brockbank packaged the hairs to Klann for a DNA analysis. Klann examined the six longest hairs in late April 1997.

"I could not obtain any DNA material from them," he said, noting that such analysis destroys the hair.

Klann returned the remaining 14 hairs to an evidence locker.

Early this year, Brockbank opened the package containing the hairs to examine them to see if they were similar to Markhasev's hair.

Brockbank found only 13 hairs, meaning one was missing, a mystery that was not resolved Wednesday.

As Brockbank looked at the hairs--this time with a more powerful microscope than the one she used earlier--she found a single 3-millimeter strand of hair with tissue material attached to the root, making it a strong candidate for DNA analysis.

She sent it back to Klann.

When Klann got it, the hair was only 2 millimeters long, one millimeter shorter than when Brockbank examined it. Hall questioned Klann about the discrepancy, but it was never resolved.

Klann concluded that the DNA from the hair matched that of Markhasev's.

Hall questioned Brockbank and Klann about why he wasn't informed about the single strand of hair before it was destroyed by the DNA analysis.

"You knew Mr. Markhasev was charged with murder and it was a high-profile case, didn't you?" he asked Brockbank. "Did you ever contact me about this?"

"No," Brockbank responded, "I've never done that with any defense attorney in a case."

When testimony resumes today, the defense will begin trying to shake Diana Paul's testimony linking the gun to Cosby.

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Hair Evidence Becomes Focus in Cosby Slaying

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With 20 strands of hair, a cap, a gun and a bullet fragment from the head of Ennis Cosby, the prosecution crossed a major hurdle Wednesday--tying 19-year-old Mikail Markhasev to the killing of the son of entertainer Bill Cosby. But reminiscent of the O.J.

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