The science used to help solve crimes is called forensic science. In criminal investigations fingerprints are one of the oldest and most common types of physical evidence found at a crime scene. Fingerprints are left behind almost every time something is touched. Since every person has a unique set of prints, they are a great tool for identification.
Some fingerprints are visible; you can see marks left on a surface by dirty or oily fingers. Dusting is usually used for this type. Other prints are latent; you can't see them, but there are marks left by sweat, amino acids, and other organic residue from fingers.
In recovering latent impressions there are numerous products available for the task. One of the conventional methods consists of mechanical development. Mechanical development is the use of a brush and powder to physically dust the surface. This technique allows the particles of the powder to adhere to contaminates. The mechanical development is for nonporous items and surfaces.
Gordon Brush® manufactures three types of brushes for recovering latent impressions: (1) Fiberglass; (2) Camel hair; (3) Feather brush.
For those of you with criminal minds, there is one category for brushes by Forensics & Criminology. In this category one can choose from the following fill materials: Horse hair; feathers; fiberglass; Goat Hair; and Squirrel hair. These fills are all set in a wood handle.