U.S. Air Force Tech. Sgt. Franklin Mosley, 633rd Security Forces Squadron trainer, instructs Airman Dylan Coady, 633rd SFS installation entry controller, on firing the M-4 carbine during emergency service team tryouts at Langley Air Force Base, Va., Jan. 20, 2015. The EST is a specialized element within 633rd SFS that deals with specialized threats at Air Force installations. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)