Tech. Sgt. Ajenna Smith, 422nd Security Forces Squadron noncommissioned officer in charge of training and simulated-active shooter, braces the door of an office during an exercise at RAF Croughton, United Kingdom, July 22, 2014. After her rampage, Smith found an unlocked and empty room where she could hide from Security Forces before either continuing her assault or ending her own life. (U.S. Air Force photo by Staff Sgt. Jarad A. Denton/Released)