Hair as evidence: day three Trace evidence Hair as evidence: day three

Getting started 9-17 Describe at least 3 characteristics that you can identify from the hair samples pictured to the right

Using hair as evidence 5 types of hair from human body distinguished in cross-sectional shape Head hair- usually circular or elliptical Eyebrows/lashes- circular but with tapering ends Beard/mustache- thick and triangular; usually coarse & may have double medulla Body hair- oval or triangular depending on if area has been regularly shaved; hair from arms & legs usually has blunt ends or frayed from abrasion Pubic hair- oval or triangular; buckling of hair usually present

Types of hair Beard hair Pubic hair Arm hair

Using hair as evidence Treated hair: Bleaching removes pigment granules, can make hair brittle and disturbs scales on cuticle Dyeing hair changes color of hair shaft

Hair as evidence Determining race: European: generally straight or wavy, small evenly distributed pigment granules, oval or round with minimum variation Asian: straight, densely distributed pigment, round with large diameter, thick cuticle African: curly or kinky, densely distributed pigment or clumped pigment, flattened cross section

Collection of hair evidence Questioned hair must be accompanied by an adequate number of control samples: 1. some from victim 2. possible suspects 3. anyone who may have deposited hair at the scene Control samples- 50 full length hairs from all areas of scalp- pulled 25 full length pubic hairs

Today’s assignments Today is your LAST DAY for hair assignments, so make sure you turn in all your work from this section.