In The Informant, historian Gary May reveals the untold story of the murder of civil rights worker Viola Liuzzo, shot to death by members of the violent Birmingham Ku Klux Klan at the end of Martin Luther King’s historic Voting Rights March in 1965. The case drew national attention and was solved almost instantly, because one of the Klansman present during the shooting was Gary Thomas Rowe, an undercover FBI informant. At the time, Rowe’s information and subsequent testimony were heralded as a triumph of law enforcement. But as Gary May reveals in this provocative and powerful book, Rowe’s history of collaboration with both the Klan and the FBI was far more complex. Based on previously unexamined FBI and Justice Department Records, The Informant demonstrates that in their ongoing efforts to protect Rowe’s cover, the FBI knowingly became an accessory to some of the most grotesque crimes of the Civil Rights era—including a vicious attack on the Freedom Riders and perhaps even the bombing of the Sixteenth Street Baptist Church. A tale of a renegade informant and an intelligence system ill-prepared to deal with threats from within, The Informant offers a dramatic and cautionary tale about what can happen when secret police power goes unchecked.