Where is the FBI’s authority written down?

The FBI has a range of legal authorities that enable it to investigate federal crimes and threats to national security, as well as to gather intelligence and assist other law enforcement agencies.

Federal law gives the FBI authority to investigate all federal crime not assigned exclusively to another federal agency (28, Section 533 of the U.S. Code). Title 28, U.S. Code, Section 533, authorizes the attorney general to appoint officials to detect and prosecute crimes against the United States. Title 18, U.S. Code, Section 3052, specifically authorizes special agents and officials of the FBI to make arrests, carry firearms, and serve warrants. Title 18, U.S. Code, Section 3107, empowers special agents and officials to make seizures under warrant for violation of federal statutes. The FBI’s authority to investigate specific criminal violations is conferred by numerous other congressional statutes—such as the Congressional Assassination, Kidnapping, and Assault Act (Title 18, U.S. Code, Section 351). The FBI has special investigative jurisdiction to investigate violations of state law in limited circumstances, specifically felony killings of state law enforcement officers (28 U.S.C. § 540), violent crimes against interstate travelers (28 U.S.C. § 540A0), and serial killers (28 U.S.C. §540B). A request by an appropriate state official is required before the FBI has authority to investigate these matters. In addition, Title 28, Code of Federal Regulations, Section 0.85, outlines the investigative and other responsibilities of the FBI, including the collection of fingerprint cards and identification records; the training of state and local law enforcement officials at the FBI National Academy; and the operation of the National Crime Information Center and the FBI Laboratory.

The FBI has authority to investigate threats to national security pursuant to presidential executive orders, attorney general authorities, and various statutory sources. Title II of the Intelligence Reform and Terrorism Prevention Act of 2004, Public Law 108-458, 118 Stat. 3638, outlines FBI intelligence authorities, as does Executive Order 12333; 50 U.S.C. 401 et seq.; 50 U.S.C. 1801 et seq.

This combination of authorities gives the FBI the unique ability to address national security and criminal threats that are increasingly intertwined and to shift between the use of intelligence tools such as surveillance or recruiting sources and law enforcement tools of arrest and prosecution. Unlike many domestic intelligence agencies around the world, the FBI can shift seamlessly between intelligence collection and action. This allows the FBI to continue gathering intelligence on a subject to learn more about his or her social and financial network, and shift gears quickly to arrest him or her if harm to an innocent person appears imminent. The threat of prosecution, in turn, can be used to encourage cooperation to support further intelligence gathering.