How do you locate a federal detainee?

The Federal Bureau of Prisons provides an online inmate locator tool for inmates incarcerated from 1982 to present. This database includes federal inmates, as well as a significant number of pre-sentenced offenders for the US Marshals Service and the Immigration and Naturalization Service, and the District of Columbia felons. The database can be searched by ID number or inmate name. Search results include the inmates name, register number, physical description, location, and release date (actual or projected).