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Latent Prints Help Investigators Solve the "Unsolvable"


Laser GraphicDuring an annual conference held several years ago by the International Association for Identification, the FBI set up latent print workstations and invited other law enforcement agencies to bring their latent prints for a demonstration of some new technology. Police from Georgia brought along a latent print from the scene of a sexual assault. It was run through the Bureau's Integrated Automated Fingerprint Identification System (IAFIS) and soon a match was made: the print belonged to an individual with a lengthy criminal record who was currently locked up in a Georgia jail for stealing a car.

What's a "latent" print? It's an impression -- usually invisible to the naked eye -- left on crime scene evidence that is produced by the ridged skin on human fingers, palms, and soles of the feet. A variety of techniques, including using chemicals, powders, lasers, and alternate light sources, are employed in the detection and development of latent prints. These prints are then routinely processed through local and state fingerprint databases to find a match. But if those searches come up empty-handed, the prints can also be submitted to IAFIS.

Are latent searches effective? Using the IAFIS fingerprint search capability against data from the FBI's Criminal Justice Information Services Division -- which maintains the largest repository of fingerprint records -- identifications can be made in cases for which no known suspects were named, and in cases in which latent prints didn't match the suspects named in the investigation. From 1997 through July of this year, the FBI Laboratory's latent prints experts -- while using IAFIS -- have identified 1,040 latent fingerprints of 863 persons in 601 criminal investigations. Among those identified:

* The person responsible for breaking into the house of an elderly widow while she was in the hospital and stealing a number of keepsakes. Police were able to lift several fingerprints from the house and then sent them through IAFIS. The system returned with a match: it was the woman's neighbor who had volunteered to watch the house while she was away. The suspect's rap sheet revealed that he had been arrested several times in other jurisdictions for burglary.

Are latent searches easy to conduct? Yes! Since 1999, state and federal agencies have even been able to conduct remote latent searches of IAFIS by using the CJIS network. Local law enforcement agencies have also been encouraged to use the service, with the concurrence of the appropriate state official -- the Bureau offers free remote latent software to agencies interested in processing latent prints directly through IAFIS. Police agencies are also encouraged to dig through their "cold case" files and submit latent fingerprints from significant unsolved cases to IAFIS. Here's an example of one such case:

* The Houston Police Department recently submitted latent prints from a 1969 case involving the murder of a young mother -- no one was ever arrested. The IAFIS search identified the prints as belonging to a 58-year-old ex-con who had never been a suspect in the case. Confronted by the print evidence, he ultimately confessed to the murder.

As more and more investigators begin processing their latent prints through IAFIS, there will no doubt be a comparable increase in the number of dangerous criminals being put behind bars.

Related links: FBI's Latent Print Units | IAFIS