Hair. *credit to Anthony and Patti Bertino for image. Dec 2 8:10 PM

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Andrea Peters
8 years ago
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1 Hair *credit to Anthony and Patti Bertino for image Dec 2 8:10 PM 1

2 Essential Question: How can hair be used to solve a crime? Dec 2 8:12 PM 2

3 History of hair evidence criminal evidence in 1800's 1883 The Principles and Practice of Medical Jurisprudence by Alfred Swain Taylor and Thomas Stevenson chapter on hair evidence, drawings under magnification references cases in England discusses structure of hair 1910 Le Poil de l'homme et des Animaux by Victor Balthazard and Marcelle Lambert microscopic drawings 1934 use of comparison microscope by Dr. Sydney Smith late 20th century DNA fingerprinting, neutron activation analysis Mar 13 6:58 AM 3

discusses structure of hair 1910 Le Poil de l'homme et des Animaux by Victor Balthazard and Marcelle Lambert microscopic

4 Function of hair (tricology study of hair) 1. regulate body temperature (arector pili) 2. decreases friction 3. protects against sunlight 4. sense organ 5 million hair follicles when born 2% on head lose hair as we age * hair does not continue to grow after death Mar 13 7:03 AM 4

5 Hair evidence: class evidence indicates contact used as supporting evidence resistant to chemical decomposition retains structural features for a long time Dec 2 8:14 PM 5

6 Morphology of hair: hair follicle organ located in the scalp hair grows out of here bulb root shaft structure life cycle.html Dec 2 8:29 PM 6

here bulb root shaft http://www.follicle.

7 Shaft structure:(*think pencil) cuticle: outer most layer formed by overlapping scales scales point to tip of hair helps identify animal species can make a cast of pattern using nail polish or softened vinyl morph6.htm Dec 2 8:38 PM 7

species can make a cast of pattern using nail polish or softened

$color viewed under microscope after put in liquid medium with similar refractive index pig hair 100X *credit to Anthony and Patti Bertino for image Dec 2 8:54$

8 cortex: within cuticle main body of hair shaft largest part spindle shaped cells, parallel to length of hair has pigment granules (melanin) that give hair color viewed under microscope after put in liquid medium with similar refractive index pig hair 100X *credit to Anthony and Patti Bertino for image Dec 2 8:54 PM 8

$refractive index pig hair 100X *credit to Anthony and Patti Bertino for image$

medulla:= middle looks like central canal in some animals stands out, 1/2 of hair diameter medullary index= diameter of medulla relative to diameter of hair shaft

9 medulla:= middle looks like central canal in some animals stands out, 1/2 of hair diameter medullary index= diameter of medulla relative to diameter of hair shaft humans =< 1/3, 0.33 animals = >1/2, 0.50 medullas vary person to person classification: continuous interrupted cat medulla fragmented absent rat 400X Dec 2 9:16 PM 9

10 To distinguish between animal and human hair use a Medullary Index diameter of hair s medulla Medullary Index = diameter of the hair M.I. = <.33 hair is human M.I. =>.5 or more, hair is animal *credit to Anthony and Patti Bertino for this slide Oct 1 8:53 AM 10

the hair M.I. = <.33 hair is human M.I. =>.

11 Types of Medullas *credit to Anthony and Patti Bertino for image Oct 1 8:33 AM 11

12 different animal medullas: fragmented Cow hair 100X Bat Hair 400X continuous horse hair 400X Dec 2 9:44 PM 12

13 Hair varies shape round, oval, triangular, flattened length diameter texture coarse, fine color pigment granules, dyes *credit to Anthony and Patti Bertino for image sampling: 50 hairs from head, 25 pubic hairs Mar 13 7:15 AM 13

granules, dyes *credit to Anthony and Patti Bertino for

14 Hair types on body: Head eyebrows/ eyelashes underarm beard/ mustache auxilary (body hair) pubic Mar 13 7:17 AM 14

15 head hairs: usually no medulla or fragmented Mongoloid race usually have continuous medullas animals usually have continuous or interrupted have database of 35 most common animal hairs for comparison Dec 2 9:45 PM 15

animals usually have continuous or interrupted have

16 Caucasian Oriental (Mongoloid) Negroid *credit to Anthony and Patti Bertino for images Oct 1 8:38 AM 16

17 Hair from different races Negroid Mongoloid Caucasoid *credit to Anthony and Patti Bertino for images Oct 1 8:44 AM 17

18 Additional Information Individuals of oriental origin usually have a continuous medulla Dyed hair shows color distributed in cortex and medulla Bleached hair has a yellowish tint As hair grows, natural color returns *credit to Anthony and Patti Bertino for this slide Oct 1 8:47 AM 18

medulla Bleached hair has a yellowish tint As hair grows, natural

19 Root: produces hair three stages life cycle a. anagen initial growth phase, hair follicle produces hair, up to 6 yrs. (80% 90% in this phase) if pulled out of scalp has follicular tag (DNA) b. catagen transition phase, 2 3 weeks (2% in this phase) c. telogen final growth phase, hair falls out 2 6 months Dec 2 10:12 PM 19

(80% 90% in this phase) if pulled out of scalp has follicular tag (DNA) b.

20 Identification: establish animal or human determine if hair at crime scene matches a particular individual animal vs. human easily done cat hair 400X human hair 100X Dec 2 10:29 PM 20

21 human comparisons difficult varies within individuals match color, length and diameter other features: presence or absence of medulla, distribution, shape, and color intensity of pigment granules dyed and bleached dye found in cuticle and cortex bleach removes pigment and give yellowish tint estimate time with dyed hair 1cm/month Dec 3 9:04 AM 21

22 Human vs. animal differences pigmentation humans denser toward cuticle animals denser toward medulla solid masses called ovoid bodies, esp. dogs, cattle color humans usually one color along length animals can change color abruptly, banded appearance Mar 13 8:42 AM 22

23 Medulla larger in animals than humans cuticle human imbricate animals coronal crown like (rodents, bats) spinous petal like (cats, seals, mink) Oct 1 8:42 AM 23

$evaluation use comparison microscope presumptive evidence phase contract microscope refractive index fluorescent microscope dyes fluoresce confirmed by DNA http://www.fbi.$

24 evaluation use comparison microscope presumptive evidence phase contract microscope refractive index fluorescent microscope dyes fluoresce confirmed by DNA can tell which part of the body where hair is from head little diameter variation, uniform pigmentation pubic short curly beard coarse, triangular cross section, blunt tips age hard to tell gender can tell from DNA, amelogenin gene Dec 2 10:48 PM 24

25 Testing for substances (toxins, drugs) in hair chemical analysis hair dissolved in solvent breaks down keratin to release substances then do chemical analysis (GC MS) Neutron activation analysis (NAA) hair placed on nuclear reactor and bombarded with high energy neutrons different elements give off gamma radiation with different signals signals are recorded to determine concentration can id antimony, argon, bromine, copper, gold, manganese, silver, sodium, zinc 1 in a million chance a hair has same concentrations of all nine elements Mar 13 8:49 AM 25

26 DNA analysis follicular tag when follicle is pulled out with hair, can run DNA, blood test DNA can individualize hair nuclear DNA mitochondrial DNA can't individualize, siblings would have the same mtdna usually do microscopic examination first, then if believed to match, a DNA test Mar 13 8:56 AM 26

27 Can tell if hair was cut recently by looking at the ends razor cut hair split hair hair with cut tip Dec 3 9:00 AM 27

28 can tell if pulled out if has follicular tissue = pulled out forcibly or by brush sheath shells usually present if quickly pulled out naturally shed forcibly removed shows stretching forcibly removed with tissue attached Dec 2 11:11 PM 28

29 Collection and preservation: hair from crime scene if dry, druggist fold if wet, dry first then in paper envelope standard comparison samples 50 full length head hairs pulled from scalp or cut at skin line 24 full length pubic hairs if rape case, must first comb area to remove foreign hair during autopsy hair samples collected from victim Dec 2 11:16 PM 29

Chapter 3 The Study of Hair By the end of the chapter you will be able to:

Chapter 3 The Study of Hair By the end of the chapter you will be able to: identify the various parts of a hair describe variations in the structure of the medulla, cortex, and cuticle distinguish between