Book excerpt: This authoritative set provides a one-stop resource for understanding specific FBI controversies as well as for those looking to understand the full history, law enforcement authority, and inner workings of the nation's most famous and important federal law enforcement agency. This authoritative two-volume reference resource uses a combination of encyclopedia entries and primary sources to provide a comprehensive overview of the FBI, detailing its history, most famous leaders and agents, institutional structure and authority, law enforcement responsibilities, reporting relationships to other parts of government, and major events and controversies. Today the FBI sits squarely at the intersection of major controversies surrounding the presidential campaign and administration of Donald Trump, foreign interference in U.S. elections, and politicization of law enforcement. But the FBI has always been in the political spotlight—its history is dotted with episodes that have come under heavy scrutiny, from its surveillance of civil rights leaders during the 1960s to the methods it employs to combat domestic terrorism in the post-9/11 era. And all the while, FBI agents and offices across the country continue to investigate a wide range of lawbreaking, from organized crime (in all its facets) to white-collar crime and corruption by public officials.