Abstract

Criminalistics laboratories routinely provide cold hits in police investigations by comparing DNA profiles from crime scenes to offenders residing in the Combined DNA Index System. Forensic DNA analysis is often glamorized in popular culture, where the perpetrators are identified and crimes solved within a single television episode. In reality forensic DNA hits can identify perpetrators of violent offenses, link multiple crimes committed by the same individual, or exclude suspects and exonerate the falsely accused. Unlike the media portrayals, downstream activities after a DNA identification or cold hit are often more complex. While the Federal Bureau of Investigation cites a national Data Bank of more than 7.2 million DNA profiles and 94,000 identifications nationwide, an in-depth analysis of public safety improvements made with CODIS is currently unavailable to forensic practitioners and public policy analysts. A review of case resolutions for 198 DNA database hits in San Francisco created performance metrics to provide a concrete measure of the effectiveness of DNA databasing efforts at the city and county level.