Hairs, Fibers, and Paint

1. Hairs, Fibers, and Paint Chapter 8

2. Why Study Hair? • It has been reported that approximately 100 head hairs are shed by an individual each day. • These hairs are shed on clothing and on items in the environment. • Contact between a victim and a suspect's environment can easily cause a secondary transfer of hair.

3. Why Study Hair?

4. Morphology of Hair • Class Characteristic because not individual specific • Can be used as STRONG corroborative evidence • Structure • Grows from a Hair follicle • Made up Three major parts: • Cuticle, cortex, medulla

5. The Skin

6. The Skin Hair Pore Dermal Papillae Epidermis Dermis Hair follicle Subcutaneous tissue Capillary Sweat Gland Erector muscle Fat cells Nerve ending

7. What Can Be Learned from Hair • Human or animal? • Race. • Body area of origin. • Shed or forcibly removed. • Disease • DNA • Comparison to known samples.

8. The Structure of Hair:

9. Cross Section of Hair

10. Three major parts of Hair: • Cuticle • Cortex • Medulla

11. The hair shaft is comprised of 3 different cell layers: • Cuticle: • Translucent outer layer, which protects the hair. • Flat cells layered in an overlapping formation that looks like shingles on a roof. • Cortex: • Middle layer made up of long thin cells firmly attached to each other and arranged lengthwise. • Location where nature creates natural hair coloring, a substance called melanin. • Provides hair with strength, elasticity and determines the texture and quality of hair. • Medulla: • Central core of the hair. • Composed of soft keratin. Cross Section of Hair

12. Three major parts of Hair: Cuticle • Cuticle: • Gives hair resistance to chemical breakdown and retains its structural features. • Results in important forensic use • Overlapping scales always point towards tip end of hair • Scale pattern allows for differentiation of species • Study scale by SEM or embedding into soft medium

13. Species and their Cuticle Scale Patterns • Coronal • The coronal, or crown-like scale pattern is found in hairs of very fine diameter and resemble a stack of paper cups. • Rodents, uncommon in humans • Spinous • Spinous or petal-like scales are triangular in shape and protrude from the hair shaft. • They are found at the proximal region of mink hairs and on the fur hairs of seals, cats, and some other animals. • never found in human hairs • Imbricate • The imbricate or flattened scales type consists of overlapping scales with narrow margins. • They are commonly found in human hairs and many animal hairs

14. Species and their Cuticle Scale Patterns • Coronal • Spinous • Imbricate

15. Identify the Cuticle Scale Patterns • Imbricate • Human • Spinous • Mink • Coronal • Bat

16. Cuticle Scale Patterns and chemical weathering Normal Cuticle scale Lifted Cuticle

17. Three major parts of Hair: Cortex • Cortex is the main part of the hair • Has pigment granules • Compare color, shape, distribution • Examine by mounting in a liquid with similar REFRACTIVE INDEX • Allows for less light to be reflected and light penetration is optimized

18. Each of the natural chemicals inside the human body has a specific job to do. • One of these is an amino acid called tyrosine. • The body converts this amino acid into melanin so the hair will have color. • First, the body's blood vessels carry tyrosine to the bottom of each hair follicle. • Then, in this "melanin factory" tyrosine is used as the raw material for the production of the natural melanin that is the color in hair. • In short, natural hair color depends upon the presence, amount and distribution of melanin, a natural pigment found in the cortex. Melanin

19. Medulla • Cellular column running through middle of hair • Modullarly index is how much of diameter of hair medulla takes up • Human <1/3 • Other animals >1/2 • Medulla can vary even in same individual • **Shape**: human and most animals have cylindrical shape

20. Diagram of Medullas

21. Diagram of Medullas

22. http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidencehttp://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidence Animal hair vs. Human • All unknowns are compared to: • KNOWN standards. • Them by scale structure, Medullary index and Medullary shape • –human hair generally <1/3 • –animal hair >=1/2 • •Medullary Shape • –human normally cylindrical

23. http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidencehttp://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidence Animal hair vs. Human

24. http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidencehttp://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidence Shedding vs. Removal By Force *Presence of follicular tissue on root *indicative of forcible removal *by a person *by a comb

25. http://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidencehttp://www.fbi.gov/hq/lab/fsc/backissu/july2000/deedric1.htm#Hair%20Evidence Hair Removal

26. Hair Analysis Due • Sooo, Who Done-it?

27. Human vs. Human • All unknowns are compared to: • KNOWN standards: color, length, shape and diameter. • Concentration of Medullary/ cortex pigments • Growth after Dyed or bleached? • Dyed (color) throughout • Bleached: pigments removed provides a yellowish tint

29. Hair is Class Evidence • Can often determine body area of origin • Can often determine racial origin • –Negroid•kinky with dense uneven pigment•flat to oval in shape • –Caucasian•straight or wavy fairly evenly distributed pigment•oval to round shape

30. Racial Determination Three Basic types: • Caucasoid (European) • Mongoloid (Asian) • Negroid (African) ?

32. Body Area Determination • Head Hairs: • Pubic Hairs: • Limb Hairs • Fringe Hairs • Facial Hairs A hair showing buckling

33. Body Area Determination Head Hairs:usually the longest Characterized: a uniform diameter and, often, a cut tip, appear uncut, with tapered tips but are more often cut with scissors, razors, or clippers. Appearance of hair dyes, rinses, permanents, frosts, and other chemical applications. Environmental alterations: sunlight, wind, dryness, Pubic Hairs:are also routinely compared in a forensic laboratory. *considerable variation exists between individuals in the population. Characteristics: generally coarse and wiry They exhibit considerable diameter variation or buckling and often have a continuous to discontinuous medulla. While tapered tips are common, these hairs may also be abraded or cut. *are not subject to as much change over time, and because of this, a sample taken a year or more after a crime may still be suitable for meaningful comparison purposes. A hair showing buckling

34. Facial HairsFacial hairs are more commonly called beard hairs or mustache hairs. Characteristics: are coarse in appearance and can have a triangular cross section. Heavy shouldering or troughs in the hair are observed under magnification. Other characteristics include a wide medulla and a razor-cut tip. Limb HairsHairs from the legs and arms constitute limb hairs. Characteristics: shorter in length, arc-like in shape, and often abraded or tapered at the tips. The pigment in limb hair is generally granular in appearance, and the medulla is trace to discontinuous. Fringe HairsHairs originating from areas of the body outside those specifically designated as head or pubic are generally not suitable for significant comparison purposes. These hairs might originate from the neck, sideburns, abdomen, upper leg, and back. ?

35. Sex Determination • Stained sex chromatin in the nuclei of human cells showing the female-indicative Barr body (bright spot, top)

36. Hair is a Major Source of DNA • Nuclear DNA: • hair root or aka follicular Tag: a translucent piece of tissue surrounding the hair’s shaft near the root. • Mitochondrial DNA: • Governs the powerhouse of the cell • located outside of the nucleus • Multiple per cell • Maternally inherited

37. Hair is a Major Source of DNA • Nuclear and mitochondrial DNA can be found in the root of the problem • 100 of mtDNA can be found in 1 cell • Working on extracting DNA from hair in anagen phase***. • Mitochondrial DNA currently being examined

38. Collection of Hair Evidence • Questioned hairs must be accompanied with • an adequate number of control sample hairs from victim • –from others suspected of depositing hair at Crime scene • Representative control samples–50 full-length hairs from all areas of scalp–24 full-length pubic hairs

39. Hair Growth • Three developmental stages: • Anagen phase, Active growth phase • Catagen phase, Regressive phase • Telogen phase, Resting phase

40. Hair Growth

41. Hair Growth, Anagen phase • Last up to 6 years • 85 % of hair • The root is attached to the follicle for continued growth, • Giving the root bulb a flame-shaped appearance. • **when pulled from the root some anagen hairs will be found with a follicular tag.

42. Hair Growth, Catagenphase • Two to three weeks • 3-4 % • Hair continues to grow , but at a decreasing rate. • Catagen roots appear elongated as the root bulb shrinks and is being pushed out of the hair follicle.

43. Hair Growth, Telogen phase • Final 2 to 6 month period • 10-13% • Hair growth ends • Root takes a club-shaped appearance. • Hair WILL be pushed out causing the hair to be naturally shed. • a new hair begins to form

44. In the News: http://abcnews.go.com/ Anatomy of a Crime The man who allegedly killed judge's family gives details in suicide note. DNA from a cigarette butt connects electrician to Chicago slayings Bart Ross/Bartlomiej Ciszewski

45. NEWS UPDATE:Fulton County Superior Court killed Fulton County Superior Court Judge Roland Barnes speaks during a hearing for Atlanta Thrashers' Dany Heatley in an Atlanta courtroom Feb. 6, 2005. Barnes and a court reporter were shot to death Friday, March 11, 2005 at the Fulton County Courthouse, authorities said. At least two others were wounded, and a search for the suspect was underway. (AP Photo/John Bazemore)

46. NEWS UPDATE:Fulton County Superior Court killed 33-year-old Brian Nichols Police are searching for a man who shot and killed a judge and two others at a downtown courthouse. The suspect reportedly grabbed a gun from an officer, shot several people, and is on the loose after carjacking several cars.

47. Types of Fibers • Objective: Identify the various types of fibers • Examples?? • How are they made? • How should they be analyzed? • How should they be collected?

48. Fiber Lab • Objective: To Identify the origin of your unknown fiber. • Remember it technically should be white like you standards! • Conclusion: ??

49. Fiber Lab • Objective: To Identify the origin of your unknown fiber. • Remember it technically should be red like you standards! • Conclusion: ??

50. Fiber Lab Lisa