BCCE 30 July 2012 State College, PA

1. BCCE30 July 2012State College, PA Forensic Hair Examination Jay A. Siegel, Ph.D. – Professor, Forensic Science Gina Ammerman, M.S. – Lecturer, Forensic Science Forensic and Investigative Sciences Program Indiana University Purdue University Indianapolis Indianapolis, IN

2. INTRODUCTION • Hairs make good ________ _______because they can survive for many _______, carry __________ information, and are easy and cost-effective to examine. • _______can also be extracted from hairs • Hairs offer _____ investigative and adjudicative information

3. GROWTH OF HAIRS • Hairs are a structure only common to ________ • Fibrous growths that originate from epidermis • _________ is structure within which hairs grow • Roughly cylindrical tube with a larger pit at the bottom • Hair is soft at base and hardens and dries out as it proceeds up the follicle • Hair is made of ________ • Tough protein-based material from which hair, nails, and horns are made • Hardening process is called keratinization • Hair is “dead” when it reaches our skin • Follicle contains ________ vessels, nerves and sebaceous glands, which produce ____ that coat hairs keeping them soft and pliable • ______ have muscles called pili arrector that raise hairs causing “goose bumps”

4. GROWTH OF HAIRS cont’d

5. GROWTH OF HAIRS cont’d • Hairs have ______ phases of growth • Anagen is the actively ________ phase • Follicle produces ___ _____and pushes them up the hair shaft as they become incorporated into the structure of the hair • Cells in follicle produce ________ or pigment that impart color to hair • Cells are called melanocytes

6. GROWTH OF HAIRS cont’d • Hair transitions into a______phase called catagen phase • Follicle begins to shut down production of cells, cells shrink, and root condenses into a bulb-shaped structure called a root bulb or club root • Telogen phase is the resting phase for the follicle • Cell production has ceased completely, root condenses into a bulb and it is held in place by mechanical connection at the base of the root • When connection breaks, follicle is triggered back into _______phase

8. MICROANATOMY • On macroscopic scale, hair has a root, shaft and tip • _____ is the portion that formerly was in follicle; proximal portion of hair • ______ is the main portion of the hair • ___ is the distal most portion of the hair

9. MICROANATOMY cont’d • Microanatomy of hair includes cuticle, cortex, and medulla • ________ of hair is a series of overlapping layers of scales that form a protective coating • Animal hairs have scale patterns that differ by species • Humans have scale pattern called imbricate • _______ makes up bulk of the hair; consists of spindle-shaped cells that contain or constrain numerous structures

10. MICROANATOMY cont’d • Examples of scale patterns

11. MICROANATOMY cont’d • Spindle-shaped cells are sometimes called fusiform • ________granules are found in cortex and are dispersed variably throughout the cortex • Vary in size, shape, aggregation and distribution • Small bubbles called cortical fusi may appear in cortex • May be sparse, aggregated or evenly distributed • Ovoid bodies, which look like large pigment granules, may appear irregularly in cortex • Cortical or medullary __________, which appear as small explosion in middle of hair, may be found

12. HUMAN vs. NON-HUMAN HAIRS • Relatively _____ to determine if hair is human or non-human • Determining what kind of non-human hair may be more difficult • ______ hairs have several macroscopic characteristics that distinguish them from human hairs

13. HUMAN vs. NON-HUMAN HAIRS cont’d • Guard hairs are large stiff hairs that make up the outer part of the animal’s coat • Used for microscopic identification • Guard hairs may have a widening in the upper half of the shaft called a shield • A subshield stricture may be found below the shield • A narrowing of the hair to slightly less than the normal, non-shield shaft diameter • May be accompanied by bend in shaft at stricture

14. HUMAN vs. NON-HUMAN HAIRS cont’d • Thinner, softer fur hairs fill in the rest of the coat, providing warmth and bulk • Not useful for microscopic identification • Animals have vibrissa, which are whiskers or the long, stiff often white hairs around the snout and muzzle • Some non-human hairs are color banded or show abrupt color transitions • Scale patterns may be useful in identifying animal hairs • Use scanning electron microscope or make a scale cast and view with light microscope

15. BODY AREA DETERMINATION • Humans have a wide variety of hairs on their bodies • Characteristics of these hairs may allow for an estimation of body area origin • Head, pubic, facial, chest, axillary, eyelash/eyebrow, and limb • Typically, only head and pubic hairs are suitable for microscopic comparison

16. BODY AREA DETERMINATION cont’d • Hairs not fitting into one of these categories may be called transitional body hairs • Buckling is an abrupt change in direction of the hair shaft with or without a slight twist • Shouldering is an asymmetrical cross-section of hairs • Determination of body area origin may be difficult or impossible • Labeling hair as “body hair” may be sufficient

17. ANCESTRAL ESTIMATION • ________ or ancestry of an individual from his or her hair can be estimated • Morphology and color of hair can give an indication of a person’s ancestry • Three main ancestral groups are used: Europeans, Africans, and Asians • Head and pubic hairs provide the clearest evidence for ancestral estimates • Some examiners also categorize populations as mixed race or other

18. DAMAGE, DISEASE, AND TREATMENTS • _______ may cut, dye, braid, shave, etc. their hair • Tips of hair provide good information about treatment of hair • Angle, clean straight border, long curved “tail,” blackened and bubbled or expanded, crushed • Bleaching removes pigmentation • Coloring may be added to hair

19. DAMAGE, DISEASE, AND TREATMENTS cont’d • Some ________ affect hair or follicles and are distinctive • Pili annulati refers to hairs with colored rings • Monilethrix makes hairs look like a string of beads • Pili torti is a twisting of the hair along its length • ________ on hair should be noted • _____ and sex cannot be determined from looking at hairs

20. COMPARISON OF HUMAN HAIRS • Goal of most forensic hair examinations is the comparison of a questioned hair or hairs from a crime scene to a known hair sample • Known hair sample consists of 50-100 hairs from all portions of area of interest • Comparison microscope is used for examination

21. COMPARISON OF HUMAN HAIRS cont’d • Examined from root to tip, at magnifications of 4x to 250x • Three basic conclusions can be drawn from a forensic hair comparison:

22. COMPARISON OF HUMAN HAIRS cont’d • The questioned hair could have come from the same person who provided the known sample • Not a positive form of identification • No conclusion can be drawn as to whether the questioned hair could have come from the known source • The questioned hair did not come from the known source

23. DNA AND HAIRS • mtDNA offers a way to add information to microscopic hair examinations • Microscopic and molecular analyses are complementary techniques

24. SUMMARY • Hairs are among the most often collected and potentially useful types of trace evidence • Microscopical comparisons and mitochondrial _____ yield information