1. Human Hair Analysis Hair and Fiber 1

2. Hair Analysis Encountered in a wide variety of crimes Encountered in a wide variety of crimes Especially useful in rape cases Especially useful in rape cases Also useful in illegal drug usage cases (toxicology) Also useful in illegal drug usage cases (toxicology) Many attempts have been made to positively identify a suspect but all have failed Many attempts have been made to positively identify a suspect but all have failed Hair is usually class characteristic only Hair is usually class characteristic only Typically need more than one Typically need more than one

3. Vital Properties Species identification Species identification Color/Pigment Color/Pigment Length Length Diameter Diameter Internal characteristics Internal characteristics Dye/Bleaching Dye/Bleaching

4. Hair as Evidence Hair evidence is evaluated by physical microscopy or chemical analysis Hair evidence is evaluated by physical microscopy or chemical analysis Toxicology Toxicology Hair acts like a time capsule Hair acts like a time capsule Base of hair shows most recent use Base of hair shows most recent use Protein structure “freezes” evidence of drugs, heavy metals, etc. in hair Protein structure “freezes” evidence of drugs, heavy metals, etc. in hair Typical human head hair growth is 1 cm per month Typical human head hair growth is 1 cm per month Rape/Homicide Rape/Homicide Source of DNA in follicular tissue Source of DNA in follicular tissue

5. Hair as Evidence Species identification Species identification Most species of mammals are distinctly different from each other under a microscope Most species of mammals are distinctly different from each other under a microscope Human ethnicity Human ethnicity Can usually identify ethnicity in humans Can usually identify ethnicity in humans

6. Human Ethnicity Caucasoid Caucasoid Usually straight or wavy Usually straight or wavy Evenly distributed, usually fine pigmentation Evenly distributed, usually fine pigmentation Oval to round cross section Oval to round cross section Fragmented/absent medulla Fragmented/absent medulla Mongoloid Mongoloid Usually straight Usually straight Usually even, dense pigmentation Usually even, dense pigmentation Continuous medulla (defining characteristic) Continuous medulla (defining characteristic) Negroid Negroid Kinky Kinky Dense, unevenly distributed pigment Dense, unevenly distributed pigment Flat to oval cross section Flat to oval cross section Fragmented/absent medulla Fragmented/absent medulla “Buckling” often seen “Buckling” often seen Typical human hair cross sections

7. Hair Evidence Myths Age Age Age can not be determined with any amount of certainty Age can not be determined with any amount of certainty Only infants seem to have distinct characteristics Only infants seem to have distinct characteristics Usually very fine Usually very fine Gender Gender Gender can not be determined without follicle and DNA analysis Gender can not be determined without follicle and DNA analysis Male/Female structure identical Male/Female structure identical Differences mainly genetic in nature Differences mainly genetic in nature

8. Hair Evidence Myths DNA extraction DNA extraction Can be extracted from follicular tissue or root (in some cases) Can be extracted from follicular tissue or root (in some cases) Cut hair without the root usually does not contain enough DNA to type Cut hair without the root usually does not contain enough DNA to type If forcefully removed, follicle tissue w/ DNA likely attached to root If forcefully removed, follicle tissue w/ DNA likely attached to root Hair that falls out naturally does not contain adhering tissue Hair that falls out naturally does not contain adhering tissue

9. Body Hair Types Forensically valuable hair Forensically valuable hair Scalp hair Scalp hair Little diameter differences Little diameter differences Uniform pigment Uniform pigment Exposure to environmental conditions make immediate processing vital Exposure to environmental conditions make immediate processing vital Pubic hair Pubic hair Vary widely in diameter Vary widely in diameter Usually curly Usually curly Short length Short length Less exposure to elements allows for collection long after crime Less exposure to elements allows for collection long after crime

10. Body Hair Types Lesser forensic value Lesser forensic value Most other body hairs are too variable in appearance to be valuable for forensics Most other body hairs are too variable in appearance to be valuable for forensics Characteristics are in no way linked to patterns found on scalp hair Characteristics are in no way linked to patterns found on scalp hair Can be used to determine a suspect’s presence at scene but not often used Can be used to determine a suspect’s presence at scene but not often used Three types Three types Limb - arm, leg Limb - arm, leg Fringe hair - neck, sideburns, upper leg, back Fringe hair - neck, sideburns, upper leg, back Axillary - eyebrows, nose, underarm Axillary - eyebrows, nose, underarm

11. Hair Structure Structural components Structural components Epidermis Epidermis Outermost layer of skin Outermost layer of skin Pitted with hair follicles Pitted with hair follicles Root Root Portion of hair below skin Portion of hair below skin Follicle Follicle Only segment of hair that is living Only segment of hair that is living Source cells from which hair grows Source cells from which hair grows Below skin in the bulb Below skin in the bulb

12. Hair Structure Structural components Structural components Arrector (Erector) Muscle Arrector (Erector) Muscle Can cause hair to stand on end Can cause hair to stand on end Also source of “goosebumps” Also source of “goosebumps” Many animals have control over these muscles Many animals have control over these muscles

13. Hair Structure Structural components Structural components Hair shaft Hair shaft Composed of protein keratin Composed of protein keratin Structurally the same as fingernails Structurally the same as fingernails Three layers Three layers Cuticle, Cortex, Medulla Cuticle, Cortex, Medulla

14. Hair Structure Structural components Structural components Cuticle Cuticle Provides support for hair Provides support for hair Non-living Non-living Consists of overlapping external scales different than most other mammals Consists of overlapping external scales different than most other mammals Scales very resistant to decomposition Scales very resistant to decomposition Makes for perfect physical evidence Makes for perfect physical evidence

15. Hair Structure Structural components Structural components Cortex Cortex Inner layer of hair Inner layer of hair Contain pigment granules Contain pigment granules Melanin protein Melanin protein Distribution of pigment helps to determine particular individuals Distribution of pigment helps to determine particular individuals

16. Hair Structure Structural components Structural components Medulla Medulla A “tube” of cells that run up the center of the cortex A “tube” of cells that run up the center of the cortex Width of medulla is vitally important in identifying species Width of medulla is vitally important in identifying species Ratio of hair width to medulla width is called medullary index Ratio of hair width to medulla width is called medullary index

17. Hair Structure Structural components Structural components Medulla Medulla Humans have less than 1/3 medulla, most other animals at least ½ Humans have less than 1/3 medulla, most other animals at least ½ Comparison of human hair (left), deer hair (top) and dog hair (right)

18. Hair Structure Structural components Structural components Medulla Medulla Not always present in certain ethnicities Not always present in certain ethnicities One person can have multiple medulla structures One person can have multiple medulla structures Continuous Continuous Interrupted Interrupted Fragmented Fragmented

19. Human Medulla Types Typical human medulla types. From left to right: Continuous, Interrupted, Fragmented.

20. Hair Structure Artist’s conception and electron microscope images of a human hair with cuticle, cortex and (to a lesser extent) medulla

21. Hair Growth Growth cycle has three distinct phases Growth cycle has three distinct phases Hair can stay on head for approx. 6 years Hair can stay on head for approx. 6 years If forcefully pulled out and in one of first two phases, follicle tissue will likely be found with the hair follicle If forcefully pulled out and in one of first two phases, follicle tissue will likely be found with the hair follicle (right) Diagram showing the three phases of hair growth

22. Hair Growth Anagen Anagen Up to six years Up to six years Root attached to follicle Root attached to follicle Root will have a “flame” shape Root will have a “flame” shape If pulled out, will usu. have follicular tissue and show evidence of stretching/force If pulled out, will usu. have follicular tissue and show evidence of stretching/force Growth originates at base of hair and grows up Growth originates at base of hair and grows up 80-90% of all hair will be in this phase 80-90% of all hair will be in this phase (Above)Electron microscope image showing new anagen follicles erupting from the epidermis. (Below) A typical anagen follicle with attached tissue.

23. Hair Growth Catagen Catagen Two to three weeks Two to three weeks Growth slower Growth slower Root shrinks and is pushed out of follicle Root shrinks and is pushed out of follicle Usu. has a shrunken appearance Usu. has a shrunken appearance 2% of all hair 2% of all hair Transition phase Transition phase

24. Hair Growth Telogen Telogen Two to six months Two to six months No growth No growth Root has a club shape with no tissue Root has a club shape with no tissue Is shed naturally Is shed naturally 10-18% of all hair 10-18% of all hair A typical telogen hair follicle. Note the absence of follicular tissue.

25. Hair Microscopy Damaged cuticle showing loose scales. Typical wear and tear with dislodged scales and other debris on hair follicle.

26. Hair Microscopy Severely damaged hair that may be the result of braiding or forceful removal. A “split end” on a hair follicle. Also note evidence of cutting by sharp scissors. Electric clippers usually leave much more ragged marks.

27. Hair Microscopy A twisted/stretched root…clear indicator of forceful removal. Tight, twisted appearance and scorch marks of hair exposed to high heat.

28. The Atlanta Child Murders 1979-1981, 29 black males were murdered (ages 7-16 except for last 7 who were 17-27) 1979-1981, 29 black males were murdered (ages 7-16 except for last 7 who were 17-27) Strangled, beaten, asphyxiated Strangled, beaten, asphyxiated Only common evidence were fibers and presence of dog hair Only common evidence were fibers and presence of dog hair Two artificial fibers ID’ed Two artificial fibers ID’ed After info. leaked to press, M.O. changed and bodies were dumped in river After info. leaked to press, M.O. changed and bodies were dumped in river PD staked out Chatahoochee River PD staked out Chatahoochee River PD heard a loud splash and stopped a suspect (Wayne Williams) PD heard a loud splash and stopped a suspect (Wayne Williams) Claimed it was garbage Claimed it was garbage Suspect released but body later found nearby w/ single carpet fiber in hair Suspect released but body later found nearby w/ single carpet fiber in hair

29. The Atlanta Child Murders Warrant obtained for Williams’ house and found matching carpet and dog hair/fibers Warrant obtained for Williams’ house and found matching carpet and dog hair/fibers Expert assistance obtained from DuPont corporation Expert assistance obtained from DuPont corporation Exhaustive use of statistical likelihood of particular carpet being found in a single Atlanta home 1:7792 Exhaustive use of statistical likelihood of particular carpet being found in a single Atlanta home 1:7792 Additional fiber matches w/ victims’ found from Williams’ car Additional fiber matches w/ victims’ found from Williams’ car Chevrolet assisted in this part of investigation Chevrolet assisted in this part of investigation Statistical possibility 1:3828 Statistical possibility 1:3828

30. The Atlanta Child Murders Combined, 1:30 million chance of both matches being achieved Combined, 1:30 million chance of both matches being achieved In total, 29 fiber type matches found between Williams’ possessions and victims In total, 29 fiber type matches found between Williams’ possessions and victims Found guilty after 12 hours of deliberation Found guilty after 12 hours of deliberation Serving 2 life sentences Serving 2 life sentences Still maintains innocence and has attempted retrials Still maintains innocence and has attempted retrials Wayne Williams at his arraignment in February 1982.