The Special Reaction Team with the Provost Marshal’s Office aboard Marine Corps Air Station Iwakuni, Japan, go through a scenario during the Advanced Active Shooter Course April 7 - 18, 2014. According to Mike McSwain, an instructor at Marine Corps Police Academy East, the active shooter course came about as a result of the Columbine High School massacre for the patrol officer to be able to make an entry during an active threat scenario.