Trace Evidence

Trace Evidence

Part I

Hair!

Reasons to like Hair:

Reasons to like Hair:

• Resists chemical decomposition

Reasons to like Hair:

• Resists chemical decomposition

• Retains structure

Reasons to like Hair:

• Resists chemical decomposition

• Retains structure

• Locard’s Exchange

Reasons to NOT like Hair:

Reasons to NOT like Hair:

• Cannot be individualized

Reasons to NOT like Hair:

• Cannot be individualized

• Variable morphology within individuals

Basic Hair Structure

The Cuticle

The Cuticle

Human.

Dog.

Deer.

Wabbit.

Cat.

The Medulla

Medulla

Continuous

InterruptedMedulla

Continuous Clear Medulla

Wafer Medulla

Bubbly Medulla

The Root

Root Life Cycle

Anagen Phase

Catagen Phase

TelogenPhase

Hair Class Characteristics:

Hair Class Characteristics:

• Color

Hair Class Characteristics:

• Color

• Length

Hair Class Characteristics:

• Color

• Length

• Diameter

Hair Class Characteristics:

• Color

• Length

• Diameter

• Treatment

Hi . . .

Hi . . .

HI!

Hi . . .

HI!

Baby, yes.

Baby, yes.

Grandpa, nope.