The Latent Print discipline within the Michigan State Police Forensic Science Division processes evidence of all types for the possible presence of latent prints. The laboratories also accept latent print lifts from all law enforcement agencies within the state of Michigan. The purpose of the latent print examination is to determine a connection between an object and a person. Connecting a person to an item or location can be very strong evidence that can assist with investigations of a crime.
The basic premises that support identifying an individual using latent prints have gone unchanged since the early 1900's. However, the methods to develop and compare latent prints, including the utilization of computerized databases such as the Automated Fingerprint Identification Systems (AFIS), have changed drastically and continue to evolve. Fingerprint powders are complimented with chemical development and forensic light source applications. Traditional photography has evolved into digital photography with computerized enhancement capabilities.
Porous and nonporous evidence can be examined for latent prints. Latent prints can be compared with known recorded impressions (fingerprint cards). Recorded impressions from unknown deceased, incapacitated, or uncooperative subjects can also be compared with known recorded impressions. These same latent prints and unknown impressions can be searched in the Michigan Automated Fingerprint Identification System (AFIS), a database of known impressions from subjects who have submitted fingerprints, palm prints, and registered latent prints from unsolved crimes. A successful search can result in a positive identification.
AFIS is a computerized system for electronically encoding, searching, and matching tenprint records (fingerprint cards) and latent fingerprints and palm prints collected from evidence or crime scenes. Currently, AFIS contains millions of fingerprint records in the Tenprint Database and over 150,000 registered latent fingerprints and palm prints in the Unsolved Latent Database. The majority of known fingerprint and palm print submissions to the AFIS are performed electronically via Livescan terminals located at various law enforcement and correctional facilities throughout the state. Latent database searching is performed by MSP examiners at each of the seven laboratories. Beginning in 2004, latent print examiners were provided access to the FBI's Integrated Automated Fingerprint Identification System (IAFIS). Searching this database of fingerprint records, in excess of 50 million records, is performed directly from the laboratory's AFIS terminals.
Today's examiners must possess a Bachelor's of Science degree with chemistry as a part of the curriculum. The examiners are then required to successfully complete an extensive two-year training program under the supervision of a senior latent print examiner. They are given a strong foundation of the history and theory of latent prints as well as instruction in photography of latent prints, processing of evidence and crime scenes, and the comparison of latent prints against known impressions.