Quick Quiz: Forensic Hair Examination

A Quick Quiz for Amateur Sleuths
What Do You Know About the Forensic Examination of Hair?

03/16/05

If you’re a fan of TV crime dramas, you know that hair strands can provide a goldmine of forensic evidence. Examining hair under a microscope and analyzing its DNA helps identify victims and criminals, rule out suspects, and reconstruct crime scenes.

Our Scientific Working Group on Materials Analysis has just published a set of guidelines on collecting, examining, and identifying hair samples in the latest issue of Forensic Science Communications. It’s a bit long and technical, so we’ve tried to capture the most interesting information in the quiz below. Make your best guess and click to see how you did. Good luck!

1. The study of hair is known as:
a) Lithology
b) Histology
c) Phytology
d) Trichology
ANSWER

2. The scaly, outer portion of hair is called:
a) The follicle
b) The medulla
c) The cuticle
d) The cortex
ANSWER

3. By carefully examining hair under a microscope, we can usually tell all but:
a) A person’s race
b) A person’s gender
c) Where on the body the hair came from
d) Whether it’s been permed or not
ANSWER

4. A microscopic hair exam can positively identify an individual. True or false?
a) True
b) False
ANSWER

5. Which hairs provide the most features for comparison to other hairs?
a) Scalp hair
b) Chest hair
c) Limb hair
d) Facial hair
ANSWER

6. Extra Credit. The picture in the graphic to the left is:
a) A dog hair
b) An example of a bad hair day
c) A bat hair
d) Not a hair at all
ANSWER

Want to know more?

Answers

Question 1. Trichology (d).
If you answered histology (the study of living tissues), you were close. Just for your information, lithology is the study of rocks and phytology is the study of plants. Hairdressers are sometimes called trichologists.

Question 2: The cuticle (c). The follicle is the cavity where hair grows. The medulla is the center or core of hair; and the cortex is the main body of hair—the region between the cuticle and the medulla.

Question 3. A person’s gender (b).
There are no characteristics that tell us whether a hair is from a man or a woman, but we can sometimes make an educated guess by the condition of the hair (for example, lots of hair spray!).

Question 4. False (b).
Forensic examiners can tell a lot by looking at scale patterns, roots, color, length, shaft characteristics, and more. We can tell if a hair was forcibly removed, damaged by burning, dyed or bleached, and cut by glass. Sometimes, we can even figure out if the person was ill. These are important clues. But a microscopic look at hair can’t absolutely identify the owner. Since few people have the exact same hair characteristics, however, microscopic exams can provide compelling evidence that hair samples are associated with a certain person. If the hair root has tissue, DNA testing can provide absolute identity.

Question 5. Scalp hair (a). Under a microscope, scalp hair and pubic hair reveal a greater range of characteristics than other kinds of human hair, so we use them more often in forensic comparisons.

Question 6. A bat hair (c).
Determining whether or not a hair is human is one of the first things we do when examining our samples. So we have to know what the hair for all kinds of animals look like—especially dogs, cats, deer, and rabbits.