MT. PLEASANT, S.C. - Chief Master Sgt. Tim Winfree (left) and Tech. Sgt Bradley Krause subdue an aggressor during a mock hostile situation at the Active Shooter Training Course here, Feb. 23. The AST course prepares first responders on how to react to a hostile situation. Chief Winfree is the 50th Mission Support Group superintendent and Sergeant Krause is the NCOIC of training with the 50th Security Forces Squadron, both are from Schriever AFB, Colo. (U.S. Air Force photo by James M. Bowman/released)