CODIS

About CODIS

DNA profiling is a powerful tool used by law enforcement to help solve crimes. The CODIS Section is responsible for generating DNA profiles for offenders required to provide a sample under state statute.

Profiles generated from these samples are entered into CODIS, the Combined DNA Index System. Maintained by the FBI Laboratory, CODIS blends forensic science and computer technology into a tool for solving crimes, enabling federal, state, and local crime laboratories to exchange and compare DNA profiles electronically, and so to link crimes to one another and to offenders.

The FBI publishes further detail in its CODIS and NDIS Fact Sheet, which opens in a new tab.

How CODIS Generates Leads

CODIS generates investigative leads in cases where biological evidence was recovered from a crime scene. Profiles from crime scene samples are searched against the forensic, convicted offender, arrestee, and missing persons indices.

When two or more cases match, the investigating officers are notified, helping agencies across jurisdictions coordinate their efforts and share leads. Matches between the forensic index and the offender indices can give investigators the possible identity of a perpetrator, which has been particularly valuable in older cases where a suspect was never developed. Investigators then decide whether to pursue the lead by obtaining a DNA standard from the individual and submitting it to the DNA Casework section for comparison against the original evidence. As more profiles are entered, the chance of matching evidence to a possible suspect increases.