Andy Anderson, 4th Security Forces Squadron lead security forces law enforcement special weapons and tactics officer, instructs Airmen how to ensure hallways are safe with a weapon during an active shooter training exercise, March 3, 2016 at Seymour Johnson Air Force Base, North Carolina. With 20 Airmen per class, the training course provides basic information on how to defend yourself or escape from a building during an active shooter incident. (U.S. Air Force photo/Airman 1st Class Ashley Williamson)