Processing Fingerprints Processing Fingerprints Automated Fingerprint Identification System

Processing Fingerprints

Processing Fingerprints ¡ Automated Fingerprint Identification System (AFIS) l Provides law enforcement agencies with a computerized method for generating suspect lists from fingerprint data

Reminder… Latent prints are impressions produced by the ridged skin on human fingers ¡ There a number of ways to develop latent prints. ¡

Developing Latent Prints ¡ Fluorescencel Certain properties of latent print residue will fluoresce when exposed to a laser light Detects prints on surfaces not suitable for powder/chemicals ¡ Must be preserved through photography ¡

Developing Latent Prints Continued ¡ Powder – l Come in various colors such as black, gray, white, red and super black. It is best to select a powder that is in contrast to the surface on which is being processed.

Powders ¡ Regular powders may be used on any surface, which is relatively smooth and non-tacky

Powders ¡ ¡ Magnetic powders are sometimes more effective on rough, grained or porous surfaces, which would otherwise become heavily coated with regular powder After being “dusted, ” prints are then lifted with tape

Developing Latent Prints Continued ¡ Chemical Enhancement – l Apply something that will chemically react with one of the chemicals of latent fingerprints. The new chemical composition will make the latent fingerprints easily visible

Chemical Enhancement Examples Superglue – reacts with amino acids, fatty acids, and proteins in the fingerprint and the moisture in the air to produce a visible, sticky white material that forms along the ridges of the fingerprint ¡ Ninhydrin ¡

Superglue Fuming

Ninhydrin