In his capacity as a high official in the International Brotherhood of Teamsters, Sheeran was a leading figure in the corruption of unions by organized crime. Shortly before his death, Sheeran confessed to killing Teamster leader Jimmy Hoffa, and notorious mobster Joe Gallo. Sheeran made a deathbed confession to his Lawyer, stating that "the JFK Assassination was a mafia hit." According to Sheeran, Mafia bosses Carlos Marcello, Sam Giancana, and Santo Trafficante, Jr ordered the JFK Assassination, Sheeran stated that he provided the sniper rifles to the four mafia hitmen, and that there were four shooters in four different buildings. Sheeran stated that "Carlos Marcello, Santo Trafficante, Jr, and Sam Giancana paid off Lee Harvey Oswald to be the fall guy, and also hired mafia hitman Jack