U.S. Department of Justice (DOJ), executive division of the U.S. federal government responsible for law enforcement. Headed by the U.S. attorney general, it investigates and prosecutes cases under federal antitrust, civil-rights, criminal, tax, and environmental laws. It controls the Federal Bureau of Investigation, the Federal Bureau of Prisons, the Drug Enforcement Administration, the Office of Justice Programs, the U.S. Marshals Service, and the U.S. National Central Bureau of Interpol, among many other agencies.