Hair is essentially a fibrous filament originating from a follicle in the human skin. The portion of hair that is inside the skin is called the root (or proximal end), while the tip is referred to as the distal end.  Hair is found on almost all mammals and while the combined microscopic and macroscopic characteristics cannot establish an identity, these characteristics can be used to see if there is a uniqueness when comparing one persons hair to another.

This subdiscipline of Trace Evidence deals with the examination and identification of hairs found at a crime scene or found on evidence that originated from a crime scene.  Humans loose over 100 hairs through the normal course of a day.  Hairs are commonly found on clothing, car upholstery, rugs and other flooring, bedding, bathrooms, etc.  In other words, hair is found all over the place.

Examination and identification of hair essentially means that evidence that is suspected to be a hair will be examined with microscopes and other magnifiers to see verify that they are indeed hair as hair can resemble fibers and vice versa.  Then the hair will be further classified as to whether it is human or other animal hair.  Lastly, it will be further classified as to what part of the body the hair originated from.  The most common hairs found are head and pubic.

The second step in an examination is the comparison portion of the analysis.  If there are known suspects or victims, samples of their hair are taken and analyzed.  They are analyzed for their gross features such as color, thickness, length, root type (growing root, resting root, or in between root)