In this Thursday, Aug. 9, 2012 photo, Danville police work on “response to active shooter” training in the hallways at Danville High School in Danville, Ky. The school closed down in the afternoon and all of the teachers and staff where gone for the day. The training is commonly referred to as ìdiamond formation,” where a team of police officers learn how to respond to an active to shooter in a building with two officers on wing, one on the point and on the rear. Training takes place about once a year. (AP Photo/The Advocate-Messenger, Clay Jackson)
