Sormenjälkitekniikat

Sormenjälkitekniikat refers to the methods and processes used to collect, preserve, analyze, and compare latent fingerprints. These techniques are a fundamental part of forensic science, playing a crucial role in criminal investigations by identifying individuals who may have been present at a crime scene. The primary goal of fingerprint analysis is to match a latent print found at a scene to a known fingerprint from a suspect or a database.

The process typically begins with the detection of latent prints. These are invisible to the naked eye and are formed by the transfer of natural oils and perspiration from the ridges of a finger onto a surface. Various methods are employed for visualization, depending on the type of surface. For non-porous surfaces like glass or metal, techniques such as powder dusting (using fine powders that adhere to the residue) or cyanoacrylate fuming (where superglue fumes react with the print residue) are common. For porous surfaces like paper or cardboard, chemical treatments like ninhydrin or iodine fuming are often used to develop the prints.

Once visualized, latent prints are photographed or lifted using specialized tape. The lifted prints are then analyzed by trained fingerprint examiners. They examine the unique characteristics of the print, known as minutiae, which include ridge endings, bifurcations (where a ridge splits into two), and dots. A comparison is made between the latent print and a known print, looking for a sufficient number of matching minutiae points in the same relative positions to establish an identification. Automated Fingerprint Identification Systems (AFIS) are also used to rapidly search large databases of known fingerprints, assisting examiners in their work. The reliability of fingerprint evidence in court relies on the expertise of the examiner and established standards for comparison.