CODIS, DNA, AND THE DATABASES

The FBI Laboratory’s Combined DNA Index System is better known as CODIS. CODIS blends forensic science and computer technology into an effective tool for solving violent crimes. CODIS enables federal, state, and local crime labs to exchange and compare DNA profiles electronically, thereby linking crimes to each other and to convicted offenders. Originally a pilot project begun in 1990, CODIS has evolved from its origination as serving 14 state and local laboratories to its current nationwide level. The DNA Identification Act of 1994 formalized the FBI’s authority to establish a national DNA index for law enforcement purposes. It was in October 1998 that the FBI’s National DNA Index System – NDIS – became operational. CODIS is implemented as a distributed database with three levels – local, state, and national. NDIS is the highest level in the CODIS Program, exchanging information on a national level. All DNA profiles originate at the local level (LDIS), then flow to the state (SDIS) and national (NDIS) levels. CODIS generates investigative leads using two indexes: the forensic and the offender indexes. The Forensic Index contains DNA profiles from crime scene evidence. The Offender Index contains DNA profiles of individuals convicted of sex offenses and other violent crimes which are included in the DNA requirements of the particular local and state agencies. Matches in the Forensic Index can link crime scenes from different jurisdictions, possibly identifying serial offenders. Police agencies can coordinate their respective investigations, sharing leads they may have developed independently, when a Forensic Index match occurs. Matches between the Forensic and the Offender Index provide investigators with an identity of the culprit. It is noted that all states are participating in the National DNA Index System (NDIS), except for Mississippi, Rhode Island, and Hawaii. DNA evidence collected at a crime scene is analyzed by a forensic laboratory at the local level; Once typed, the profile is then run against the convicted-offender DNA profiles in the State Databank to attempt to make a match. In addition, profiles from other unsolved cases are compared against it to identify serial crimes. If no match occurs at the state level the profile is uploaded to the Federal DNA Index System for comparison with DNA profiles from other states. DNA profiles remain in the Federal Databank and are regularly searched against new profiles as they are added to the system. It is important to remember, as an investigator, that once a match is made of the suspected profile the search will usually end. If there is no “match” locally, it is submitted to the state; if no match in the state, then it is submitted to the federal database. This is important to keep in mind. The investigator should keep in contact with the ME’s Office analyst; this will ensure that the appropriate checks which you want done are so completed.