The Forensic Biology Section identifies bodily fluids, primarily semen and blood, to analyze for DNA. Trained biologists also collect and preserve trace and potential contact DNA evidence. Analysts test evidence from a variety of crimes, but most of the work is related to sexual assaults.
When a DNA profile is detected it is compared to reference samples from individuals associated with the case. The goal is to match an unknown profile to an identified profile and either identify or eliminate crime suspects. Profiles can also be entered into the national DNA database, or the Combined DNA Index System (CODIS,) to look for a match. CODIS includes profiles from local, state and federal databases.