Fingerprint Evidence - What Is Evidence?

What is evidence? Well this answer changes for every different crime scene. Every crime scene has evidence and something is always left behind at the scene. According to Adams (2004), one of the best forms of identification evidence when available is fingerprints. Fingerprints are perhaps the most widely recognized instrument in investigations (Adams, 2004). It is also widely recognized and popular to every citizen from all the CSI related television shows and movies. Fingerprinting has served all governments worldwide during the past 100 years to provide accurate identification of criminals. Fingerprinting is an example of nature clashing with technology. When the human finger touches a surface it leaves behind a combination of natural oils, sweat, and other contaminants which the finger has come in contact with, in the form of the ridges of their skin (Fisher, 2000). These ridges are one of a kind to every person, and are permanent from birth to death unless something happens to a person's fingers. In this paper I would like to address information on fingerprints, techniques and processing of this type of evidence.

There are a few different types of fingerprints and impressions. An inked fingerprint is when a person gets ink applied to their fingers and then makes an impression on a fingerprint card (Adams, 2004). Inked fingerprints can be used to rule out innocent persons and victims whose prints were found at the crime scene these prints are called elimination prints.

There are latent fingerprints, which you cannot see with the naked eye without the right tools used. The latent prints are formed from contaminants such as skin oils being left behind on something or someone. Newton (2006) states that temperatures above 86 degrees Fahrenheit could damage latent fingerprints and temperatures below freezing should be warmed up before attempting to do any development. Patent prints are visible to the human eye without any kind of adjustments. Patent prints are formed from transferring a material from the finger to another surface. Patent prints are also formed by impressions in a soft surface like wet paint. Plastic prints are three dimensional formed from the impression into soft surfaces like putty.

Each finger has a different pattern. There can be a combination of loops, ridges, and whorls.

Newton (2006) states the following statistics about fingerprints:

"Radial and ulnar loops are the most typical fingerprint making up around 65% of prints. 25 to 35 percent of prints are classified as double loop whorl, central pocket whorl, and plain whorl prints. Plain arch, radial arch, ulnar arch, and tented arch only make up about five percent of prints." The patterns can be compared to those found at crime scenes and to databases such as AFIS, which is the Automated Fingerprint Identification System. Either manually