1 Hair Analysis

2 Functions of Hair Regulates body temperatureArrector pili muscles contract to create “goosebumps” Protection against sunlight In nonhuman mammals, hair is known as fur Can be used as physical evidence Identify individuals Narrow down group of suspects Trace evidence that overrides other evidence Can place an individual at a crime scene

3 Anatomy of Hair Composed of dead keratinized cells, melanin, lipids, and water mtDNA can be extracted from these cells Only transferred from mother Produces sebum in order to Protect Lubricate Waterproof Inhibit microorganisms

4 History in hair Nicolaus Copernicus was buried in a Cathedral in Poland beneath the altar floor, and his remains were unmarked In 2005, his skull and remains were unearthed by archaeologists and extracted mtDNA from teeth and femur bone There were two hairs found in Copernicus’ library back in Sweden and the mtDNA matched the remains in Poland In 2010, his remains were reburied where originally found

5 Anatomy of Hair Composed of three layers Cuticle is the outer regionCortex is the area between the cuticle and medulla where pigment granules of melanin are located Medulla is the middle region

6 Cuticle Translucent outer region of hairScales point toward the tip of the hair Can feel directionality by running fingers to end and then run back to scalp 6-10 cells thick Protects hair with waterproofing Susceptible to damage Pattern determines species

7 Cuticle

8 Cortex Pigment molecules Bulk of the hair shaftDiffers in the color, shape, and distribution of granules

9 Medulla Center part of the hair shaftCan be interrupted, missing, or continuous Medullary index Ratio of hair shaft to medulla >0.5 = animals >0.3 = humans

10 Medulla

11 Hair Analysis – Origin of SpeciesAnimal Human Pigmentation Denser toward the middle Denser toward the cuticle Banded color patterns Possible None Medulla Thicker Thinner

12 Hair Analysis – Origin of LocationShape and length indicates body location Location Description Head hair Circular or elliptical Little diameter variation More uniform color distribution Eyebrows/Eye lashes Circular – often tapered Beard hair Thick and triangular Course with double medulla Blunt ends Body hair Oval or triangular Arms/legs – blunt tip/frayed ends Pubic hair Buckling may be present Large variation in diameter Continuous medulla

13 Hair Analysis – origin of LocationPubic (buckling) Arm/Leg (frayed end) Beard (double medulla)

14 Stages of Hair DevelopmentLength of cycle if genetically programmed Humans – each follicle has its own timeline Animals – timed to occur simultaneously at times of shedding Anagen Hair actively grows May last up to six years Root is attached to the follicle (bulb shape) Catagen Hair grows and changes 2-3 weeks Roots elongate in appearance Telogen Follicle becomes dormant Hair is pushed out of the follicle (shedding) 2-6 months 4-5 year cycle on human head 3-4 months for eyebrows

15 Hair Analysis – Origin of RaceAppearance Pigment Granules Cross-Section Other Info European Generally straight or wavy Small and evenly distributed Oval or round of moderate diameter with minimal variation Colors include red, blond, brown or black Asian Straight Densely distributed Round with large diameter Thick cuticle Continuous medulla African Kinky, curly, or coiled Densely distributed, clumped, may differ in size and shape Flattened with moderate to small diameter and considerable variation

16 Hair Analysis – Origin of RaceEuropean Asian African Appearance Cross-Section

17 Challenge! Cat Horse Pig Human Deer Dog Rabbit Rat HumanUse the photos below to identify the organism that the hair comes from Choices: Cat Deer Dog Horse Human Pig Rabbit Rat *One of the above is used twice! Cat Horse Pig Human Deer Dog Rabbit Rat Human

18 Other Info… Hair grows out of the skinChemicals that skin absorbs can be incorporated into hair Arsenic Lead Cocaine Morphine Tobacco Heroin Amphetamines Environmental exposure (dirt, smoke) Long term use of alcohol

19 Analysis of Hair Analyzing hair at different locations along the shaft gives a timeline of exposure Neutron activation analysis Can detect different elements in a 2 cm long piece of hair by concentration Probability if 2 individuals having the same concentration of different elements is one in one million

20 HAIR fORENSICS Hair identification process involves the examination and comparison of hair characteristics along the entire length of the hair Longer hairs have more characteristics to compare and greater variation along the length Hair evidence is usually only used in conjunction with other evidence

21 Hair Forensics

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23 Fiber Analysis

24 Fiber Makeup Natural fibers Synthetic fibers Monomer: glucoseAnimal hair Plants (seeds, fruit, stems, leaves) Minerals Synthetic fibers Monomer: glucose Polymer: cellulose

25 Difference between Warp and Weft?

26 Identify the weave pattern in your shirt!Plain Alternating warp & weft threads Firm & wears well Snag resistant Low tear strength Tends to wrinkle Basket Alternating patterns of 2 weft threads crossing 2 warp threads Open or porous weave Does not wrinkle Not very durable Tends to distort as yarn shifts Shrinks when washed Satin One weft crosses over 3 or more threads Not durable Tends to snag & break during wearing Shiny surface High light reflectance Little friction with other garments Twill Weft woven over 3 or more warps and then under one. Next 2, the pattern is shifted over one to the left or right by one warp thread Very strong Dense & compact Different faces Diagonal design on surface Soft & pliable Leno Use 2 warp threads & a double weft thread.  The 2 adjacent warp threads cross over each other.  The weft travels left to right and is woven between two warp threads Open weave Easily distorted with wear and washing Stretches in one direction only

27 Natural Fibers - AnimalsWool/Cashmere – sheep Mohair – goats Angora – rabbits Silk – caterpillars Hair from alpacas, llamas and camels

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29 Natural Fibers - Plant Absorbs water Insoluble in waterVery resistant to damage from harsh chemicals Dissolvable only in acids Becomes brittle over time Deteriorates more quickly Cotton – most common Coir (coconuts) – most durable Hemp, jute, flax – from stems Sisal – from leaves

30 Natural Fibers - MineralsFiberglass – a fibrous form of glass Asbestos – crystalline structure Used to make shingles, floor tiles, and brake liners Both used for insulation

31 Synthetic Fibers - RegeneratedRayon Most common Artificial silk Irritates natural fibers, but stronger Celenese ® Cellulose chemically combined with acetate Found in many carpets Polyamide nylon Cellulose combined with 3 acetate units Breathable and lightweight Used in performance clothing

32 Synthetic Fibers - PolymersMan-made fibers Petroleum based Strongest Formed by polymerization Fibers spun into yarns No internal structures Uniform diameters Usually used in production of carpet fibers

33 Synthetic Fibers - PolymersPolyester Polar fleece Wrinkle resistant Not easily broken down by light or concentrated acid Added to natural fibers for strength Nylon Easily broken down by light and concentrated acid Otherwise similar to polyester Olefins High performance Quick drying Resistant to wear Acrylic Inexpensive Tends to “ball” easily Substitute for artificial wool or fur

34 Natural V. Synthetic FibersCotton Flax Silk Wool Synthetic Flattened hose appearance Up to 2 inches long tapering to a blunt end May have a frayed “root” Hollow core not always visible “Bamboo stick” Straight with angles but not very curved “nodes” are visible every inch or so Often occur in bundles of several fibers Do not taper, yet exhibit small variations in diameter May be paired (raw silk) with another fiber No internal structure Surface scales may be visible Hollow or partial hollow core Fibers up to 3 inches long tapering to a fine point Vary widely in cross-sectional shape and diameter Generally straight to gentle curves Uniform in diameter May have surface treatments that appears as spots, stains, or pits

35 Yarns, Fabrics, textilesFibers twisted or spun together Clockwise or counterclockwise How tight (twists/inch) Number of fibers Strength – ply Fibers are woven into fabrics or textiles WARP – threads arranged side by side WEFT – threads woven back and forth crosswise through warp

36 Fibers as Evidence Serve as a form of both class and trace evidenceEasily transferred from the victim to the suspect Often overlooked by the suspect Easily be collected and stored

37 Identifying Fibers by FlameObservations made from a flame test Smell of the burned fiber Does the fiber melt in the flame? Color and structure of the residue left after the fiber burns

38 Part of larger piece of clothFiber Analysis Composition Chemical analysis ID monomer Monomer or copolymer Orientation of the monomer Cross-linking between chains Physical Properties Melting point Crystallinity Refractive index Opacity Shape/Morphology Microscopic examination Light microscope Electron microscope Comparison microscope Part of larger piece of cloth Coloration (dye) patterns Unique Features Striations Cutting marks Extrusion shapes