1. The Wonderful World of Hairs and Fibers

2. Different Scopes used to analyze hair and fiber Compound light Comparison Dissecting Polarized Scanning Electron Microscope (SEM)

3. Stages of Hair “Life” Anagen –Growing stage –Up to 6 years possible –Root shaped like “flame” –Hair grows ~1cm/month (1” every 10 weeks)

4. Catagen –~3 weeks long –Dormant, resting stage –Root  gets longer and thinner Stages of Hair “Life”

5. Telogen –~6 months –Root  Club shaped Pushes out and is shed –Lose approximately 70 hairs/day Stages of Hair “Life”

6. Human Hair Parts 1. Root 2. Follicle 3. Shaft 4. Tip 1 23 4

7. Human Hair Parts 1. Distal (tip) 2. Proximal (root end) 3. Medulla 4. Cuticle (contains scale pattern) 5. Cortex 1 2 3 4 5

8. Scale patterns Imbricated Mosaic Petal Pectinate Chevron

9. Medulla Types Continuous Fragmented Intermittent/interrupted

10. Medullary Index of Hair To find the MI –Diameter of medulla/hair shaft diameter Humans = <1/3 Other animals = >1/2 Classify Medulla as: –Continuous, Interrupted, Fragmented, or Absent

11. Example Medulla Patterns that can be seen Lattice Vacuolated Uniserial Multiserial

12. Deer, Dog & Muskrat hair Muskrat Deer

13. Which is Caucasian, Negroid, Mongoloid Head Hair? Caucasian, Europeans, Mexicans, Middle Easterners: oval to round Negroid, Africans oval to flat Mongoloid, Orientals, American Indians: round

14. Pulled Hair v. Shed Hair Telogen stage Anagen Stage Pulled Hair

15. Razor, Cut hair & Split hair Razor Cut Split

16. Human eyebrow

17. Burned hair

18. Buckling of hair seen in pubic hair

19. Hair match This is the view that a comparison scope can give when comparing two matching hairs

20. The small things in life Dust Mite Eyelash mites Bedbug feeding on flesh

21. Fibers

22. Types of fibers Natural fibers –Animal fibers are most common at crime scene Man-made

23. Natural fibers Animal: –Wool from sheep most common –Goats, camel, alpaca, rabbit, mink, llamas, beaver Plant: –Cotton most common –Flax (linen), ramie, sisal, jute, hemp Excrement: –Silk from silkworm (cellulose from mulberry leaves) Mineral: –Asbestos

24. Cotton fibers cross-section

25. Wool fibers v. Cotton fibers Wool Cotton

26. Flax Fibers

27. Hemp fibers

28. Silk fibers Raw thrown Wild silk

29. Asbestos fibers

30. Man-Made fibers Regenerated fibers –Machine made from natural materials like cotton or wood –1910 rayon, then acetate, then triacetate Synthetic fibers –Most fibers are made synthetically from chemicals –1939 nylon, then polyester and acrylic –Shape or cross-section can determine value of the fiber; manufacturer specific

31. Nylon fiber cross sections

32. Acetate Fibers

33. Nylon fibers

34. Orlon Fibers

35. Polypropylene fibers