Active shooter
Senior Airman Benjamin Edwards acts as an active shooter during the Anti-Terrorism/Force Protection exercise March 20, 2012 at Joint Base Charleston, S.C. Joint Base Lewis-McChord, Wash., officials announced that a similar exercise will be conducted Dec. 12, 2012 at both Lewis Main and McChord Field. (U.S. Air Force photo/Airman 1st Class George Goslin)