1. Forensics of Hair Analysis

2. Hair Forensics Hair: Can demonstrate physical contact with Person
Place
Object

3. Hair Facts
Grows from the papilla…but past that, it’s dead cells and protein – no DNA
A shaft projects above the skin, and a root that is imbedded in the skin

4. Hair: Components Keratin (a protein) Melanin (a pigment) Trace metals
Deposited in the hair during its growth
Absorbed from the external environment.
After a period of growth, the hair remains in the follicle in a resting stage to eventually be sloughed from the body.

5. Basic Hair Structure

6. Hair Cuticle
Translucent outer layer of the hair shaft consisting of scales…
… always point from the root end of the hair to the distal or tip end of the hair.

7. Cuticle
There are three basic scale structures that make up the cuticle
Combinations and variations of these types are possible.
Imbricate,
Flattened
Spinous,
Petal-like
Coronal,
Crown-like

8. Bat Hair and Mink Hair

9. Human Hair
Imbricate or “flattened” scales show overrlapping scales with narrow margins.
Can show on many animal hairs.

10. Medulla
The medulla is a central core of cells that may be present in the hair.
Human
Animal
Deer

11. Medulla When present in human hairs:
Generally less than 1/3 the diameter of the hair shaft.
In animal hairs:
Normally continuous
Generally more than 1/3 the diameter of the hair shaft.

12. Animal vs. Human Hairs Human hairs Animal hairs
Color consistent the length of the shaft
Pigmentation evenly distributed, or slightly more dense toward the cuticle
Animal hairs
May exhibit radical color changes in a short distance, called banding.
The pigmentation is more centrally distributed, perhaps although more dense toward the medulla.

13. Hair Forensics: DNA
Often it is not possible to extract DNA fully, or there is not enough tissue present to conduct an examination.
DNA examinations destroy hairs, eliminating the possibility of further microscopic examination.

14. Forensic Identification
Human hairs can generally be identified by racial origin and body area.
Racial indicators apply primarily to head hairs.

15. Caucasian
African-American
Mongoloid - Asian

16. Where is this hair from?
Certain features of individual hairs identify the region of the body where it originated.

17. Where is this Hair from?
Limb

18. Where is this hair from?
Beard triangular in cross-section

19. Things to consider when viewing hair
Length:
May have been cut
May vary considerably within the individual
Tip:
May be affected by grooming and hygiene

20. Glass-Cut or Broken Hair Tip
Cut Hair Tip
Worn or Razor-Cut Tip

21. Dyed hairs possess an unnatural cast or color
Dyed hairs possess an unnatural cast or color. In addition, the cuticle will take on the color of the dye

22. Scissor Cut
Razor Cut
Broken Hair
Burned Hair

23. What is this?

24. Joann