1. Hair Morphology 12/3/18

2. Dyed hairs possess an unnatural cast or color
Dyed hairs possess an unnatural cast or color. In addition, the cuticle will take on the color of the dye

3. Hair Follicle Components
Root and other surrounding cells in the hair follicle
Tools necessary to produce hair and continue its growth
Follicular tag
Hair pulled from the head
Translucent tissue surrounding the hair’s shaft near the root
DNA analysis on follicular tag leads to hair being individualized.

4. Hair Growth: 3 Stages
Anagen -initial phase may last up to 6 years, root is flame shaped
Catagen –transition phase (2-3 weeks), root is elongated
Telogen –phase where hair naturally falls out of the skin, root is club-shaped

5. Hair Growth Cycle

6. Hair Bulbs Brushed-out hairs all have this kind of root
A normal telogen hair with a hard 'club' end, seen under (left) light microscope and (right) electron microscope
This is an anagen hair, one which was pulled out and not ready to be shed
An anagen hair that has been plucked out: notice the soft, sticky tail

7. Forensic Evaluation Comparing Strands
Comparison microscope
Match the color, length, and diameter.
Distinguish human hair from the hair of animals
Scale structure
Medullary index
Medullary shape

8. Forensic Evaluation Comparing Strands
Other important features
Presence or absence of medulla
Distribution, shape, and color intensity of pigment granules present in the cortex
Most common request
Hair recovered at the crime scene = hair removed from the suspect
Subjective and highly dependent on the skills and integrity of the analyst