At the request of Reps. Blagojevich and Waxman, the Special Investigations Division and the Office of Special Investigations of GAO investigated criminal organizations that use fifty caliber sniper weapons. This investigation found numerous instances in which these weapons were involved in serious crime, including the use of fifty caliber weapons by Branch Davidions at Waco, during multiple homicides at a shopping center in Colorado, and in a foiled assassination attempt against Cuban leader Fidel Castro.