# Federal Bureau of Investigation *Domestic intelligence and principal federal law enforcement agency of the United States* The Federal Bureau of Investigation (FBI) is both the principal federal law enforcement agency of the United States and its domestic intelligence and security service.[^1] It sits within the [[United States Department of Justice]], belongs to the U.S. Intelligence Community, and answers to the attorney general and to the director of national intelligence.[^1] Its jurisdiction covers more than 200 categories of federal crimes, and it keeps a list of its top 10 most wanted fugitives.[^1] Founded in 1908 as the Bureau of Investigation (BOI), the agency took its present name in 1935. Its headquarters is the J. Edgar Hoover Building in Washington, D.C.[^1] The Central Intelligence Agency has no law enforcement authority and gathers intelligence abroad. The FBI, by contrast, works mainly inside the country through 56 field offices in major cities and more than 400 resident agencies in smaller cities and areas.[^1] At a field office, a senior FBI officer also acts as the representative of the director of national intelligence.[^1] Outside the United States the bureau keeps Legal Attache (LEGAT) offices in U.S. embassies and consulates. Their main purpose is coordination with foreign security services, and they do not usually act unilaterally in host countries.[^1] Its national-security work is described as comparable to that of the British MI5 and NCA and the Russian FSB.[^1] ## History In 1896 the National Bureau of Criminal Identification was founded to supply agencies nationwide with information for identifying known criminals.[^2] After President William McKinley's assassination in 1901 raised a perception of threat from anarchists, President Theodore Roosevelt sought more power to monitor them. The Departments of Justice and Labor had already kept records on anarchists for years.[^2] The Justice Department had been charged with regulating interstate commerce since 1887 but lacked the staff to do it. It did little about that shortage until the Oregon land fraud scandal around the turn of the 20th century.[^2] Roosevelt directed Attorney General Charles Bonaparte to organize an autonomous investigative service answerable only to the attorney general. Bonaparte sought personnel, investigators in particular, from other agencies, including the U.S. Secret Service.[^2] On May 27, 1908, Congress barred the Justice Department from using Treasury employees in this way, citing fears that the new agency would become a secret police department.[^2] On July 26, 1908, Bonaparte drew on Department of Justice expense funds to hire thirty-four people for the new agency, some of them Secret Service veterans. Stanley Finch was its first "chief", a post now titled "director".[^2] Bonaparte informed Congress of these steps in December 1908.[^2] ## Mission, priorities and budget The bureau states its mission as to "protect the American people and uphold the Constitution of the United States".[^3] Its listed priorities include: - defending the country against terrorist attacks; - defending it against foreign intelligence operations, espionage and cyber operations; - combating significant cybercriminal activity and public corruption at all levels; - protecting civil rights; - combating transnational criminal enterprises, major white-collar crime and significant violent crime.[^3] The same record documents outputs to set beside that self-description. In 1985 it was found that the FBI had used surveillance devices on numerous American citizens between 1940 and 1960.[^4] Senate hearings in the early 1980s examined FBI undercover operations after the Abscam controversy, which involved allegations of entrapment of elected officials. In the years that followed, a number of guidelines were issued to constrain FBI activities.[^5] For fiscal year 2019 the bureau's total budget was approximately $9.6 billion.[^3] In its Authorization and Budget Request to Congress for fiscal year 2021, the FBI sought $9,800,724,000. Of that, $9,748,829,000 was for Salaries and Expenses and $51,895,000 for Construction. The Salaries and Expenses line rose by $199,673,000.[^3] ## Organization The bureau's structure combines the Office of the Director, home to most administrative offices, with functional branches, each under an executive assistant director.[^6] Assistant directors head the offices and divisions within each branch. Deputy assistant directors lead the sub-branches, and section chiefs head the sections beneath them.[^6] Four branches report to the deputy director and two to the associate director.[^6] The branches are: - Intelligence; - National Security; - Criminal, Cyber, Response, and Services; - Science and Technology; - Information and Technology; - Human Resources.[^6] The National Security Branch contains the Counterintelligence Division, the Counterterrorism Division, the Weapons of Mass Destruction Directorate, the High-Value Detainee Interrogation Group and the Terrorist Screening Center.[^6] ## Legal authority The bureau's mandate rests on Title 28 of the U.S. Code, Section 533, under which the Attorney General may "appoint officials to detect and prosecute crimes against the United States".[^5] Additional federal statutes assign it authority over particular crimes.[^5] The Racketeer Influenced and Corrupt Organizations (RICO) Act is the bureau's chief instrument against organized crime.[^5] The FBI is responsible for enforcing compliance with the [[Civil Rights Act of 1964]] and for investigating violations of it, and it prosecutes those violations together with the Department of Justice.[^5] It also enforces the Controlled Substances Act of 1970, sharing concurrent jurisdiction with the Drug Enforcement Administration.[^5] The USA PATRIOT Act expanded the bureau's powers, chiefly over wiretapping and the monitoring of Internet activity.[^5] Its "sneak and peek" provision lets the FBI search a home while the occupants are absent and delay notifying them for several weeks.[^5] Under the Act the bureau also resumed requesting the library records of terrorism suspects.[^5] Material gathered in an FBI investigation goes to the appropriate U.S. Attorney or Department of Justice official.[^5] ## Infrastructure Besides its Washington headquarters and 56 field offices, the bureau keeps over 400 resident agencies across the country.[^7] The lead and Infrastructure sections of the cached Wikipedia article give different figures for the overseas presence. The lead counts 60 LEGAT offices and 15 sub-offices.[^1] The Infrastructure section counts over 50 legal attachés.[^7] Many specialized functions are based in Quantico, Virginia. A "data campus" in Clarksburg, West Virginia, holds 96 million sets of fingerprints, including some that American authorities collected from prisoners in Saudi Arabia, Yemen, Iraq and Afghanistan.[^7] As of the October 2026 retrieval, the Records Management Division, which handles Freedom of Information Act requests, was described as in the process of moving to Winchester, Virginia.[^7] The [[Washington Post]] reported that the FBI was building a repository, controlled from a top-secret vault on the fourth floor of the Hoover Building. According to that report, the repository holds profiles of tens of thousands of Americans and legal residents who are "not accused of any crime". It states their entry rested on appearing suspicious to a town [[sheriff]], a traffic officer or a neighbor.[^7] The FBI Laboratory dates from the BOI's formation but moved into the Hoover Building only on that building's completion in 1974.[^7] It is the primary lab for most DNA, biological and physical work.[^7] ## Personnel On December 31, 2009, the FBI employed 33,852 people: 13,412 special agents and 20,420 support professionals.[^8] The Officer Down Memorial Page records 87 FBI agents and two K9s killed in the line of duty between 1925 and February 2021.[^8] ### Hiring Agent applicants must be aged 23 to 37, although preference-eligible veterans may apply after 37. They must be U.S. citizens, hold at least a four-year bachelor's degree, and have at least three years of professional work experience.[^8] Every employee needs a Top Secret clearance, and many need TS/SCI.[^8] Clearances follow Single Scope Background Investigations conducted by the Office of Personnel Management. Personnel must pass a polygraph that includes questions on drug use.[^8] The bureau kept a minimum height requirement of 5 feet 7 inches until 1975.[^8] ### Directors The president nominates FBI directors, and the [[United States Senate]] must confirm them for a fixed term of office.[^8] ## Firearms On qualifying, a special agent receives a full-size Glock 22 or compact Glock 23 pistol in .40 S&W.[^9] The bureau adopted the Glock for general agent use in May 1997 and first issued it to New Agent Class 98-1 that October.[^9] In June 2016 Glock won a contract to supply the bureau with new handguns in 9x19mm Parabellum, the full-size Glock 17M and compact Glock 19M.[^9] ## Publications The monthly *FBI Law Enforcement Bulletin*, produced by the FBI Law Enforcement Communication Unit, began in 1932 as *Fugitives Wanted by Police*.[^10] The bureau started issuing crime reports in the 1920s from figures gathered from local police departments.[^10] In the 1960s and 1970s that method was found to miss crimes that victims never reported. The Department of Justice therefore developed the victimization survey as an alternative.[^10] The Uniform Crime Reports draw on data from over 17,000 law enforcement agencies. They concentrate on violent crimes, hate crimes and property crimes.[^10] ## eGuardian Launched in January 2009, eGuardian lets the FBI share tips on possible terror threats and suspicious activities with local, state, tribal and federal agencies in near real time.[^11] It derives from Guardian, a classified tool used inside the FBI and shared with vetted partners since 2005.[^11] ## Controversies The bureau's history includes numerous disputes, both domestic and foreign.[^4] - **Operation Pacifier.** To facilitate sting operations, the FBI ran more than half of the child pornography websites on the dark web.[^4] - **Puerto Rican independence advocates.** Congressman Luiz Gutierrez disclosed that Pedro Albizu Campos and his Nationalist party had been watched for a decade-long period in the 1930s.[^4] - **Whitey Bulger.** The Boston Field Office has been criticized for its handling of the Boston criminal, who served as an informant.[^4] - **Latin America.** During the Cold War the bureau placed agents to monitor Caribbean and Latin American governments.[^4] According to WikiLeaks documents, the FBI trained Egyptian State Security agents at its Quantico academy.[^4] - **Domestic surveillance.** As noted above, it was found in 1985 that the bureau had used surveillance devices on numerous American citizens between 1940 and 1960.[^4] - **Robert Hanssen.** Hanssen evaded the FBI while selling thousands of classified American documents to Soviet intelligence. The Department of Justice called the case "possibly the worst intelligence disaster in U.S. history".[^4] ## Media portrayal Popular media have portrayed the FBI since the 1930s. The bureau's role has ranged from direct involvement in developing films and television series to consulting on operations and closed cases.[^12] ## Notes [^1]: Wikipedia contributors, *Federal Bureau of Investigation*, lead section (rev. 1382077765, retrieved 2026-10-26) — mandate, reporting lines, jurisdiction, field offices, LEGAT offices, founding and renaming dates, headquarters. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^2]: Wikipedia contributors, *Federal Bureau of Investigation*, "History" section (rev. 1382077765, retrieved 2026-10-26) — background to and creation of the Bureau of Investigation, May 27 and July 26, 1908. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^3]: Wikipedia contributors, *Federal Bureau of Investigation*, "Mission, priorities and budget" section (rev. 1382077765, retrieved 2026-10-26) — mission statement, priorities, FY2019 and FY2021 budget figures. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^4]: Wikipedia contributors, *Federal Bureau of Investigation*, "Controversies" section (rev. 1382077765, retrieved 2026-10-26) — Operation Pacifier, Puerto Rican files, Bulger, Latin America, 1985 domestic-surveillance finding, Hanssen. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^5]: Wikipedia contributors, *Federal Bureau of Investigation*, "Legal authority" section (rev. 1382077765, retrieved 2026-10-26) — 28 U.S.C. § 533, RICO, Civil Rights Act of 1964, Controlled Substances Act, USA PATRIOT Act, Abscam hearings and guidelines. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^6]: Wikipedia contributors, *Federal Bureau of Investigation*, "Organization" section (rev. 1382077765, retrieved 2026-10-26) — branch structure, reporting lines and National Security Branch divisions. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^7]: Wikipedia contributors, *Federal Bureau of Investigation*, "Infrastructure" section (rev. 1382077765, retrieved 2026-10-26) — resident agencies, legal attachés, Quantico and Clarksburg, Records Management move, Washington Post report, FBI Laboratory. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^8]: Wikipedia contributors, *Federal Bureau of Investigation*, "Personnel" section (rev. 1382077765, retrieved 2026-10-26) — employee counts as of December 31, 2009, line-of-duty deaths, hiring requirements, director appointment. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^9]: Wikipedia contributors, *Federal Bureau of Investigation*, "Firearms" section (rev. 1382077765, retrieved 2026-10-26) — issued sidearms, May/October 1997 adoption, June 2016 contract. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^10]: Wikipedia contributors, *Federal Bureau of Investigation*, "Publications" section (rev. 1382077765, retrieved 2026-10-26) — Law Enforcement Bulletin, crime statistics history, Uniform Crime Reports. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^11]: Wikipedia contributors, *Federal Bureau of Investigation*, "eGuardian" section (rev. 1382077765, retrieved 2026-10-26) — January 2009 launch and Guardian predecessor (2005). https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation [^12]: Wikipedia contributors, *Federal Bureau of Investigation*, "Media portrayal" section (rev. 1382077765, retrieved 2026-10-26) — the bureau's depiction and involvement in popular media. https://en.wikipedia.org/wiki/Federal_Bureau_of_Investigation