Evolving out of the serology laboratory, where testing was limited to blood typing and determining the presence of bodily fluids, the OCME Department of Forensic Biology is able to perform DNA testing in criminal cases and has been doing so since 1991. Homicide, sexual assault, and other crime evidence, generally collected by the Police Department, is examined and subjected to DNA extraction and typing. The results are compared to DNA profiles of known suspects and to convicted offender DNA information maintained in the FBI CODIS (Combined DNA Index System) database. DNA results can incriminate or exclude a suspect, or solve cases by finding a match to a repeat offender through the DNA database.
The Forensic Biology Missing Persons Group performs DNA testing and kinship analysis in identification cases, as well as DNA typing of unidentified remains, personal references and family comparison samples for the FBI Missing Persons Database; this database permits comparison of reference data across jurisdictions and thus provides closure to many families with missing relatives. Additionally, the Molecular Genetics team, by performing molecular testing of relevant genetic markers, supports the Medical Examiners in determining cause of death.