Fingerprint EvidenceSusan DeForge

Solving the Mystery

When police come upon a crime scene, the first thing that they do is seal off the area and prevent anyone but experts to enter. They do this so that their own hair, fingerprints and clothing do not contaminate the evidence. Contaminate: to change or alter in a negative way a crime scene can be contaminate by other people’s fingerprints.

Fingerprint Patterns

Fingerprints can be decided into three main patterns: loops, whorls, and arches.

A clear fingerprint is excellent evidence. No two fingerprints in the world are alike. A Fingerprint will remain unchanged during an

individuals lifetime

Types of Fingerprints

ArchesArches are found in about 5% of fingerprint patterns encountered. The ridges run from one side to the other of the pattern, making no backward turn. Ordinarily, there is no delta in an arch pattern but where there a delta, no re-curving ridge must intervene between the core and delta points. (Delta is a two sided triangle found in the fingerprint.)

Whorls

Whorls are seen in about 25-35 % of fingerprint patterns. In a whorl, some of the ridges make a turn through at least one circuit. Any fingerprint pattern which contains 2 or more deltas will be a whorl pattern.

Loops

Loops:  60-65% of the population has loops Must have one or more ridges entering from

one side of the print, curving and exiting from the same side