1. Ch. 3 Hair

2. Napoleon HairNapoleon Hair (watch beginning) Neutron activation analysis Neutron activation analysis (old)- 18 min Napoleon Poisoning Claims Debunked

3. Forensic Analysis of Hair Trace evidence- hair and fiber

4. Hair Evidence Class evidence 1 st job: determine if animal or human Composed of protein (keratin), an appendage of the skin that grows out of hair follicle Each species possesses hair w/ characteristics length, color, shape, root appearance & internal features Types of hair recovered & condition & number of hairs collected all impact their value as evidence

5. Morphology Study of the structure or form of hair

6. Function of Hair Regulate body temp Decrease friction Protect against sunlight Sense organ Camoflauge

7. The Structure of Hair

10. Phases (development stages) Anagen Cyclical growth Initial growth period where follicle is actively producing hair (materials are deposited in cells) May last 3-6 years, 80-90 % of hair is this phase Follicular tag- root is attached to follicle for growth, when hair is yanked out root is still attached- can use tag for DNA

12. Catagen Transition period Occurs between anagen & telogen phases 2% in this phase Roots are elongated

13. Telogen Resting phase 10-18% of hair Most commonly found piece of evidence Last about 100 days, easily dislodged Root is club shaped Final growth phase in which hair sheds

15. Parts of Hair Hair is an appendage of the skin that grows out of an organ known as the hair follicle Hair follicle: origin of growth of the root, shaft and tip club shaped structure in skin w/ network of blood vessels called papilla that supply nutrients Shaft: composed of protein keratin, consists of 3 layers

16. Cuticle Allows hair to be resistant to chemicals & allows hair to retain structural features over a long time Formed by overlapping scale (hardened cells) Scales on animals look like roof shingles Scales can be: coronal, spinous, or imbricate Study by making casts (embedded in nail polish)

17. Cortex Main body of hair Contained w/ in the protective cuticle Made of spindle-shaped cortical cells aligned in the shaft Pigment granules found in cortex (major use in evidence- get diff. shapes, color, distribution) Can look at cortex if you prepare slide w/ liquid that has same index of refrac. as hair

18. Medulla Collection of cells having the appearance of a central canal running through hair Varies among individuals Classified as continuous, interrupted, fragment, absent Medullary index (M.I.) = diameter of medulla diameter of shaft

19. Casey anthony -hair

20. Other types of human hair -used to corroborate other evidence -make connections

21. Pubic Need 25 hairs, routinely compared (head hair- normally 50) Not subject to change (sample can be taken 1 year after crime- can still be compared) Course and wiry, buckling can be present

22. Facial Not meaningful, establish contact Coarse, triangular cross section Wide medulla, razor cut tip

23. Limb Hairs Not meaningful Short, arc like Medulla – trace to discontinuous

24. Fringe hairs Neck, side burns, abdomen, upper leg, back

25. Other body hair Underarm, chest, eye, nose Not routinely compared

26. Animal Hair Used to link a suspect or location Get transfer (from animal or secondary source) Animals don’t possess enough indvl. microscopic characteristics to be associated w/ 1 particular animal Can determine type of animal or breed

27. Animal hairs vary- in color & length from different parts of the body Collect full length hairs Some hairs found may be cut  fur coat, rug, etc

28. Animals vs. Humans Animal MI  ½ or greater Medulla= continuous or interupted Shape = patterned Cat=pearl Deer = spheres Human MI  1/3 or less Medulla= fragmented or absent Shape = cylindrical

29. Age and Sex Age Can’t be determined definitively by microscope But hairs in infants  finer, less distinctive Older hair  finer, more variable in diameter Sex Can do DNA w/ follicular tag (rare) Can also stain the sex chromatin in cells (Barr body or y-body) Treated (perm,color) more frequent in females

30. Barr BodyY-Body

31. Racial Determination Caucasoid (European) Fine to medium coarseness Straight or wavy Blonde to brown/black in color Shafts – round to oval in cross section Have medium sized, evenly distributed pigment granules Color- blonde, red, brown or black

33. Mongoloid (Asian) Coarse, straight, circular cross section Wider diameter Cuticle thicker Medulla continuous & wide Pigment granules are larger than caucasoid, densely distributed Can have reddish appearance

35. Negroid (African) Curly, kinky Flattened cross section Pigment granules are larger than other groups- in clumps Can be buckled (twisted shaft) & shaft is frequently split

37. Identification and comparison of hair Hair is class evidence Identification involves: Scale structure, medullary index, medullary shape Compare: Color, length, diameter, medullary charac., cortical cells, artificial pigmentation (dyed or pigmentation – 1cm/month growth)

38. Forensic exam: Addresses body area, racial origin, mechanism of removal, possibly age or sex

39. Analysis Techniques Microscopy: Compound Comparison (most common) Fluorescence Electron Neutron Activation Analysis- method of analysis that determines the composition of elements

40. Buckled hair Burnt hair Cut tip Razor cut Split end Post mortem root band

41. Human hair Orangutan

42. Bat hair- coronal pattern Mink hair- spinious

43. Rabbit- ladder medulla

44. Dyed hair Hair w/ lice egg

45. Limb hair Pubic hair Beard hair

46. FBI Hair Website fbi video (old)