Human beings are all born with ridges that shape fixed patterns on each of their fingertips. These ridges form loops, arches, and whorls that are unique to each human being, even identical twins. As a result, physical fingerprint evidence can be used to positively identify an individual. Fingerprint science involves the process of collecting this evidence and then subsequently validating and analyzing the evidence for the purpose of identifying an individual. The formal name for fingerprint science is dactyloscopy.
Many entities regularly use fingerprint science to identify individuals. For example, a police department can use fingerprint technology in order to nab a criminal or identify a dead body. A prosecutor may build an entire case against a defendant on the basis of positive fingerprint identification. Military regimes can use fingerprint science in order to identify an officer who has been seriously injured or killed.
Typically, there are two key steps involved in fingerprint science: fingerprint identification and fingerprint matching. As part of the identification process, an examiner must find and collect any available latent and patent fingerprints. Latent prints usually refer to ridge imprints that are inadvertently left on a surface and that are not visible to the naked eye. Using fingerprint science techniques and powders or chemicals, experts can make latent prints visible during the collection process.
Patent prints, on the other hand, are left behind on a surface or fingerprint reader when a substance is moved from a fingertip to the surface or reader. For example, a patent print would result if a person dipped his or her finger in paint and then pressed it onto a canvas. Patent prints can usually be identified without chemical processing and are often considered more reliable than latent prints.
Once a fingerprint has been identified, the print must be matched. Experts frequently perform fingerprint authentication and matching using fingerprint matching software programs. In general, the software first processes the fingerprint images using algorithms that help obtain clearer images of the original imprint. The original print is then compared to any matching records in the software's database for the purpose of determining whether a probable match exists.
Fingerprint science requires more expertise than simply knowing how to use fingerprint biometrics technology. Examiners must also consider the impact of friction on a fingerprint, particularly if that print is latent. Development medium, skin elasticity, slippage, and deposition pressure can all influence the appearance of a print, and competent experts must be able to analyze these additional factors.