If you're in the business of crime scene investigation or forensic lab analysis, you have to know your fingerprint terminology. Fingerprints are complex natural patterns, and fingerprint professionals use a sophisticated jargon to describe their appearance. A patent fingerprint is different from a latent fingerprint, for example, and both differ from an exemplar fingerprint.

Fingerprints

A fingerprint is a distinctive pattern on the tip of each finger. Fingerprints have three characteristics that make them important to forensic science and criminal investigations. First, fingerprints are unique, and no two people share the same fingerprint pattern. Second, fingerprints are permanent; they do not change their overall appearance during the course of a person's life. Third, fingerprint contain characteristic features, such as whorls, loops and arches.

The features of fingerprints allow them to be classified, sorted into categories and types, and readily compared with other sets of prints. Fingerprint databases can quickly search for known comparisons by comparing the distinctive patterns on a fingerprint under investigation with the patterns of millions of prints in a database. The fingerprint database, managed by the Federal Bureau of Investigation, includes fingerprints of more than 100 million people and is considered the world's largest biometric database.

Patent Fingerprint

A patent fingerprint is a visible image of a person's fingertip left on a surface as a result of residue on the finger. A patent fingerprint can be created by blood on someone's finger, another liquid such as oil or ink, or by dirt. If you are in the fingerprint collection and identification business, a patent fingerprint is usually photographed for subsequent identification.

Plastic Fingerprint

A plastic fingerprint is a detailed impression of a person's finger left in a pliable substance, such as clay, wax or wet paint. The impression is readily visible and can be photographed as you would a patent fingerprint.

Latent Fingerprint

A latent fingerprint, in contrast, is not readily visible. It is left on a surface as the result of natural oils on the skin and can be made visible with special forensic techniques, such as the application of powders; different colored powders are used on different surfaces to enhance visibility. The resulting fingerprint pattern may be photographed after being made visible or lifted on fingerprint tape for subsequent identification.

Exemplar Fingerprint

An exemplar fingerprint is a deliberate print specifically made as part of a record, such as applying for a passport or a security-related job. A special type of fingerprint ink is usually used to make permanent exemplar fingerprints. Some systems store a digital image of the fingerprints rather than using ink.