Hair Microscopy

A Novel

What is hair anyway?

Primarily composed of the protein keratinCan be defined as slender outgrowths of the

skin of mammalsHairs can be transferred during physical

contact, so their presence can associate a suspect to a victim or a suspect/victim to a crime scene.

Hair Characteristics

Macroscopic Length Color Shape (curly vs. straight, etc.)

Microscopic Root appearance Pigment distribution Shape

Varieties of Hair on a Mammal

Humans Head Pubic Arms/Legs

Beasts Coarse,outter guard hairs Fine fur Tactile hairs (whiskers) Tail/Mane hairs

Hair Life Cycle

Anagen Growth stage At any time, 80-90% of hair is in anagen on a human

headCatagen

Tranistion stage from anagen to telogenTelogen

Dormant, resting phase Hairs in this phase fall out readily with a comb or light

contact 10-18% of hair on a head is in telogen

Naturally Shed Hair

Hair dislodged by combing or other light contact

Root is undamaged

Club shaped

Ouch! Forcibly Removed Hair

Hair is bent and/or broken

Root shows damage and stretching (top)

May have scalp tissue still attatched (bottom)

Animal Hair!

Animal hair is very useful for placing a suspect/victim in a location, as they are easily transferred by clothing

Cat or dog hairs have been found on the adhesive portions of ransom notes!

Secondary transfers also occurAnimal hairs can used to identify

species or breeds, but not individuals

Razor Cut hair

Split Hair

Hair with cut tip

Buckling

Burnt Hair

Race - Caucasoid

Race - Negroid

Race - Mongoloid