Interstate Identification Index (III)
An "index-pointer" system for the interstate exchange of criminal history records. Under III, the Federal Bureau of Investigation (FBI) maintains an identification index of persons arrested for felonies or serious misdemeanors under state or federal law. The index includes identification information, (such as name, date of birth, race, and sex), FBI Numbers, and State Identification Numbers (SID) from each state holding information about an individual. Search inquiries from criminal justice agencies nationwide are transmitted automatically via state telecommunications networks and the FBI's National Crime Information Center (NCIC) telecommunications lines. Searches are made on the basis of name and other identifiers. The process is entirely automated and takes approximately five seconds to complete. If a hit is made against the Index, record requests are made using the SID or FBI Number, and data are automatically retrieved from each repository holding records on the individual and forwarded to the requesting agency. Participation requires that the state maintain an automated criminal history record system capable of interfacing with the III system and capable of responding automatically to all interstate and federal and state record requests.
https://www.bjs.gov/index.cfm?ty=tdtp&tid=4