U.S. Air Force Staff Sgt. Amanda Cubbage, 509th Bomb Wing Security Forces Squadron military working dog handler, pursues a suspect during an active-shooter exercise at Whiteman Air Force Base, Mo., Feb. 11, 2015. The goal of the exercise is to familiarize members with how to respond to a real-world scenario. (U.S. Air Force photo by Airman 1st Class Joel Pfiester/Released)