Federal Bureau of Investigation

The Federal Bureau of Investigation (FBI) is the U.S. government agency responsible for investigating crimes, including terrorism, that involve transgression of federal law. (A very few, specific federal crimes are investigated by other agencies, for example, tax evasion is the responsibility of the Internal Revenue Service.) The bureau is part of the U.S. Department of Justice; the bureau director is appointed by the attorney general. The FBI employs almost 28,000 people, 11,000 of whom are special agents. Its headquarters in Washington, D.C., develops policy and provides support to the 56 field offices and 400 satellite offices within the United States, and the 44 posts abroad headed by legal attaches (“legats”).

The FBI was reorganized in late 2001 in response to a perceived need to concentrate on counterterrorism in the wake of the September 11, 2001, attacks on the World Trade Center in New ...