Fortunately for crime investigators, the medulla in hair is variable: Animal medullas are much larger than those of humans, and, in fact, in people with very fine hair, the shafts don't even have a medulla.

Select CrimeSceneHair.gif to see the sample that was collected in the murder victim's apartment. Adjust the contrast, if necessary (be sure to click Reset).

Then select HairSampleStk.gif to see the samples taken from five of the victim's friends and acquaintances.