Hair Hair Analysis Can be used to match a suspect with a crime scene Can be microscopically analyzed for similarity
Comparisons continue to improve as forensic techniques improve Part 1 Hair Background Grows from a collection of cells called a follicle
The hair shaft is composed of three parts: 1. cuticle outside covering of hair shaft, can look like overlapping roof shingles 2. Cortex inside the
cuticle, a pigmented layer 3. Medulla runs down the center of the hair Hair texture can
vary considerably depending upon the ratio of cuticle to The Structure of Hair The Structure of Hair
Cross-Sections Hair can vary in shape, length, diameter, texture, and color. The cross-sections can be circular, triangular, irregular, or flattened,
which influences the curl of the hair. Dog layers can have one fine coat and one coarse coat. Color Depends
granules. on distribution of pigment Hair from Different Parts of the Body Head Hair
Eyebrows/Eye Lashes Beard and Mustache Hair
Underarm Hair Auxiliary or Body Hair
Pubic Hair HEAD HAIR Cross-Section is circular or elliptical EYEBROW HAIR Cross-Section
ends is circular, but has tapering BEARD HAIR Beard: Thick and Triangular CrossSection
BODY HAIR and PUBIC HAIR Oval or Triangle, depending on the shaving routines of individual. HAIR GROWTH
Antagen Stage Catagen Stage
80-90% of all hair. Active growth around follicle. Hair changes (Turning Grey) Telogen Stage
Hair follicle is dormant or resting and hairs easily fall out. TREATED HAIR Bleaching When removes pigment granule.
hair is dyed, the hair shaft (Cuticle and Cortex) changes color. Racial Differences Animal Hair Ovoid
Bodies- clumps of pigment Animal hair can change color abruptly MICROSCOPY
Length, color, curliness Pattern of Medulla Florescence of Dyes
TESTING FOR SUBSTANCES Lead, Arsenic, Drugs Organic solvent breaks down hair over time.
Scientists can often develop a timeline. If hair is forcibly removed, it has follicular tag. DNA Testing.
