Test Review KEY: Hair and Fiber Evidence
1. Name 8 common sources of fibers.
 Carpet
 Insulation
 Clothing
 Rope
 Linen
 ligature
 Furniture
 Tape
2. What are the three sources of natural fibers?
 Plant
 Animal
 Mineral
3. Name 5 different types of animal fibers. Which is most common?
 Wool (most common)- sheep
 Cashmere- goat
 Mohair- goat
 Fur- mink, beavers, rabbit
 Silk- from silkworm
4. Name 5 different types of plant fibers. Which is most common?
 Cotton- most common
 Flax- linen
 Jute- used in ropes
 Hemp- used in rope and sacks
 Coir- from coconut husk, used for rugs/carpet
5. Name a type of mineral fiber. Why is it no longer used in insulation?
 Asbestos- causes cancer
6. Name 5 different synthetic fibers. What is the most common synthetic fiber?
 Polyester- most common
 Rayon
 Acrylics
 Nylon
 Acetates
7. What synthetic fiber is used by law enforcement and firemen due to its heat and fire resistant
properties?
 Aramid
8. Name the three main parts of a hair. Make a sketch
and label.
 Cuticle, cortex, and medulla
9. What is the name of the protein that is found in human hair?
 Keratin
10. Name and sketch the type of scales that all human hairs have.
 Imbricate
11. Name and sketch the two types of scales that animal hairs can have.
 Coronal or spinous
12. Which direction do the scales on a hair sample point?
 Towards the tip (distal end)
13. How can you tell the difference between an animal hair and a human hair?
 Pigment- consistent in humans, varies in animals
 Medulla- less than 1/3 in humans, very wide in animals
 Scale structure- imbricate for humans, spinous or coronal for animals
14. What is a postmortem root band?
 A dark band that may appear near the root of the hair originating from a decomposing
body
15. Why are fibers considered sensitive evidence?
 They are considered sensitive evidence because 95% of all fibers may be lost within 24
hours.
16. Is hair evidence considered class or individual?
 Class
17. What can and cannot be determined from analyzing a strand of hair?
 Can- whether the hair is human or animal, possible race, area of the body it came from
 Can NOT- age or gender
18. When examining hair evidence, where can nuclear DNA be found?
 In the follicular tag
o A piece of soft tissue from the follicle that is attached to the root end of hairs that
were forcibly removed
19. When is hair evidence considered to be the most significant? Give an example.
 Hair evidence is most significant when it is found in an unexpected place
o For example finding a murder victim’s hair in the trunk of a car that belongs to the
maintenance worker for the apartments the victim lives in
20. When is fiber evidence considered to be the most significant? Give an example.
 Fiber evidence is most significant when it is found in an unexpected place. Also the
more rare the fiber type the more significant
o For example finding hot pink silk fibers from a blouse owned by the victim found
on the suspect