Rowe succeeded Bill Holt in the office of "Klokan Chief" of the violent Eastview 13 Klavern in August 1960. In May 1961 he was part of the mob of Klansmen and neo-Nazis that "greeted" Freedom Riders at the Trailways Bus Depot in downtown Birmingham, severely beating several passengers with chains and clubs during a 15-minute "window" reportedly arranged beforehand by Police Commissioner Bull Connor. Rowe's participation in the fray was documented by Birmingham Post-Herald photographer Tommy Langston.
In June 1963 Rowe was one of six Klansmen arrested at a traffic stop between Birmingham and Tuscaloosa on the day that James Hood and Vivian Malone enrolled at the University of Alabama. The Alabama Highway Patrol may have acted on an FBI tip when they pulled the car over. They found the trunk full of weapons and explosives. The men were released and their weapons returned.
Members of Rowe's Klavern were responsible for the bombing of 16th Street Baptist Church in September 1963, killing four girls. Rowe himself was considered a suspect by state investigators, but solid evidence tying him to the plot was never produced. Some fellow Klan members claimed that Rowe had failed lie detector tests when denying any knowledge of the bombing plan, but those claims could not be substantiated.
Rowe was one of four people in a car that followed Civil Rights activist Viola Liuzzo down a country road in Lowndes County and sprayed her car with bullets, killing her on March 25, 1965, a day after the Selma to Montgomery March. The four men, all members of the KKK, were quickly apprehended by the FBI. Rowe's role as an informant became known when he was the only one of the four not indicted for murder. He testified at two trials in Lowndes County that ended in a hung jury and an acquittal on state murder charges, as well as in the federal trial that convicted the three men under the 1871 Ku Klux Klan Act. Afterward, Rowe was placed into a federal witness protection program and returned to Savannah as "Thomas Neal Moore". In 1975 he testified before the United States Senate Select Committee on Intelligence wearing a cotton hood to conceal his features. Based on new evidence from the other men involved, Rowe was named in a 1978 indictment for Liuzzo's murder, but was not extradited to stand trial.
He died from a heart attack in 1998 and was buried under a headstone with his assumed name.
- Rowe, Gary Thomas Jr (1976) My Undercover Years with the Ku Klux Klan. New York: Bantam Books.
- Kaufman, Michael T. (October 4, 1988) "Gary T. Rowe Jr., 64, Who Informed on Klan In Civil Rights Killing, Is Dead." The New York Times
- May, Gary (2005) The Informant: The FBI, the Ku Klux Klan, and the Murder of Viola Liuzzo. Yale University Press.
- Hebert, Keith S. (April 7, 2015) "Gary Thomas Rowe, Jr" Encyclopedia of Alabama online - accessed August 28, 2017