L3 Forensics

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• L-3 Forensics
• Hair Analysis

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Hair and Forensics

• Considered class evidence.
• Easily transferred.
• Does not decompose and maintains chemical
  stability.
• When follicle present, DNA is obtainable.

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The Structure of Hair

• 2 parts Follicle and Shaft
• The follicle is a club-shaped structure in the
  skin.
• At the end of the follicle is a network of blood
  vessels that supply nutrients to feed the hair
  and help it grow. This is called the papilla.
• Around the papilla is a sebaceous gland called
  the bulb which secrets oil to condition.
• Nerves are wrapped around the follicle that make
  hair stand up when environments change.

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Structure of Hair

• Made up of three layers
• Inner Medulla
• Cortex
• Outer Cuticle

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The Cuticle

• Transparent outer layer of the hair shaft.
• Made up of scales that overlap to protect from
  the inner layers of hair.

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Cortex

• Made up of cells.
• Largest part of the hair shaft.
• Contains the pigment granules (melanin) that give
  the hair its color.

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Pigment Granuels
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Types of Medulla

• The center of the hair is called the medulla.
• It can be a hollow tube or filled with cells,
  fragmented, segmented, continuous or even doubled.

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• Treated hair shows different characteristics. Dye
  is found in cuticle and cortex. Bleaching gives a
  yellow tint when examined. If found at a crime
  scene, simple math can determine the last time it
  was colored.
• Great differences between animal and human hair.
• Key physical characteristics can identify race.
• Analysis can also determine the location of where
  a hair may have come from on the body.

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