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CODIS Program Overview

 

Stephen J. Niezgoda
FBI Laboratory, Washington, DC

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The CODIS Program

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 profiles.

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).

Profiles Stored in CODIS

The word "index" in Combined DNA Index System is not arbitrary. CODIS is a system of pointers; the database contains only the information necessary for making matches. Profiles stored in CODIS include a specimen identifier, the sponsoring laboratory’s identifier, the names of laboratory personnel responsible for the DNA profile and the actual DNA characteristics. CODIS does not store criminal history information, case-related information, or social security numbers. When CODIS identifies a potential match, the laboratories responsible for the matching profiles contact each other to validate or refute the match. After a match has been confirmed by qualified DNA analysts, laboratories may exchange additional information – including the names and phone numbers of criminal investigators, case details and, in the case of a match in the Convicted Offender Index, the identity and location of the convicted offender.

As of December 1997, forty-eight states have passed legislation requiring convicted offenders to provide samples for DNA databasing. These states have collected approximately 450,000 DNA samples, and analyzed over 150,000. Over 90% of the U.S. population is covered by a DNA statute.

Software, Training and Support

The FBI provides CODIS software, together with installation, training and user support free of charge to any state and local law enforcement laboratories performing DNA analysis. CODIS began as a pilot project in 1990, serving fourteen state and local DNA laboratories. As of December 1997, CODIS is installed in eighty laboratories in thirty-six states. Approximately four hundred forensic examiners throughout the United States have received CODIS training.

Ultimately, the success of the CODIS program will be measured by the crimes it helps solve. CODIS’s primary metric, the "hit," is defined as a match that provides the police with an investigative lead that would not otherwise have developed. To date CODIS has produced over 200 hits, assisting hundreds of investigations.

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