Monday, April 7, 2008

Combined DNA Index System CODIS Program Overview

The FBI Laboratory’s Combined DNA Index System (CODIS) blends forensic science and
computer technology into an effective tool for solving violent crimes. CODIS enables state and
local law enforcement crime laboratories to exchange and compare DNA profiles electronically,
thereby linking serial violent crimes to each other and to known sex offenders. Following are
several examples of CODIS in action:

• Oklahoma City, Oklahoma, February 1997: In 1992 five women were bound,
gagged and stabbed in a drug house in Oklahoma City. The Oklahoma State
Bureau of Investigation developed a DNA profile for the killer in 1995, based on
evidence found at the crime scene. In 1997, the California Department of Justice
used CODIS to match the evidence profile against Danny Keith Hooks, who was
convicted of rape, kidnapping and assault in California in 1988.

• Tallahassee, Florida, February 1995: The Florida Department of Law Enforcement
linked semen found on a Jane Doe rape-homicide victim to a convicted offender’s
DNA profile. The suspect’s DNA was collected, analyzed and stored in a CODIS
database while he was incarcerated for another rape. The match was timely; it
prevented the suspect/offender’s release on parole, which had been scheduled to
occur eight days later.

• St. Paul,Minnesota, November 1994: A man wearing a nylon stocking over his
face and armed with a knife jumped out from behind bushes and assaulted a
woman who was walking by. Semen recovered from the victim’s skirt and saliva
was analyzed using DNA technology. The resulting DNA profile was searched
against Minnesota’s CODIS database. The search identified the perpetrator, who
confessed to the crime and is now in prison.

CODIS uses two indexes to generate investigative leads in crimes where biological evidence
is recovered from the crime scene. The Convicted Offender Index contains DNA profiles of
individuals convicted of felony sex offenses (and other violent crimes). The Forensic Index contains

DNA profiles developed from crime scene evidence, such as semen stains or blood spatter.
CODIS utilizes computer software to automatically search these indexes for matching DNA

Matches made among profiles in the Forensic Index can link crime scenes together; possibly
identifying serial offenders. Based on a match, police in multiple jurisdictions can coordinate
their respective investigations, and share the leads they developed independently.Matches made
between the Forensic and Convicted Offender Indexes provide investigators with the identity of
the perpetrator(s).

No comments: