There's an active shooter in the building – what now?
Marines assigned to Delta Company, 4th Law Enforcement Battalion, search for an active shooter threat while conducting high-risk response training at the Exchange on Joint Base Elmendorf-Richardson May 15. Pacific Air Forces High-Risk Response Training is a project that provides security forces personnel with an intensive course based in real-life scenarios emphasizing effective tactics to eliminate active shooters and other threats. (U.S. Air Force photo/Alejandro Pena)