Portrait of an active shooter
Tech. Sgt. Ajenna Smith, 422nd Security Forces Squadron noncommissioned officer in charge of training and simulated-active shooter, waits for the fake blood from her artificial head wound to properly set during an exercise at RAF Croughton, United Kingdom, July 22, 2014. As an active shooter, Smith said she would have exhibited signs of frustration, anger and isolation that friends and coworkers could have identified prior to the actual rampage. (U.S. Air Force photo by Staff Sgt. Jarad A. Denton/Released)