John Kost, 28th Security Forces Squadron flight chief, simulates a firing scenario with an M4 rifle at Ellsworth Air Force Base, S.D., March 10, 2015. 28th SFS members engage in more than 200 hours of training annually, from combative skills to taser and law enforcement training. (U.S. Air Force photo by Airman 1st Class Rebecca Imwalle/Released)