The Combined DNA Index System (CODIS) is the FBI's national databases of genetic identification codes. Each DNA sample is stored as a 13 digit number.

CODIS consists of two sub-databases. The forensic index contains DNA evidence found at crime scenes. The offender index links DNA samples to known offenders of sex offenses and other violent crimes. CODIS is just primarily a national database for DNA data accumulated at local and state levels. All 50 states participate.

As of September 2004, 94,00 forensic profiles and 1.9 million offender profiles have been accumulated. As of the same date, CODIS has produced over 17,200 matches to requests, assisting in more than 20,300 investigations.

The CODIS server itself is hidden at an unknown location.

There are many privacy and ethical concerns accompanying CODIS. The foremost is that CODIS represents the holy grail of eugenics. The database could be interpreted to yield the criminal gene. Such a discovery would have tremendous potential for abuse.

CODIS currently does not have such capacity. First, it does not store actual genetic information- just identification codes. Secondly, the identification codes are created from so called "junk DNA". This DNA is not believed to have any function or influence on human characteristics.