6/21/2012 - RAF MILDENHALL, England – Capt. Meghan Norwood, 100th Security Forces Squadron, walks through Washington Square, RAF Mildenhall, while pretending to be a disgruntled Airmen-turned-assailant, during an active shooter exercise June 20, 2012. The exercise was held to help teach and prepare Team Mildenhall members how to react in a real-world active shooter situation. (U.S. Air Force photo/ Senior Airman Ethan Morgan)

6/21/2012 - RAF MILDENHALL, England – Airmen from the 100th Security Forces Squadron clear out the 100th Comptroller Squadron Finance Office after reports that an assailant with a gun had entered the building during an active shooter exercise held at RAF Mildenhall June 20, 2012. Security forces first responders were evaluated during the exercise on their ability to respond, access the situation and neutralize the threat. (U.S. Air Force photo/ Senior Airman Ethan Morgan)

6/21/2012 - RAF MILDENHALL, England – Senior Airman Marcus Pace, (left) 100th Security Forces Squadron patrolman, calls in the status of the situation to the base defense operations center during an active shooter exercise held at RAF Mildenhall June 20, 2012. After reporting to the BDOC, Pace provided self-aid-buddy-care to Tech. Sgt. Joshua Lewis, (right) 100th SFS, after he sustained a simulated gun-shot wound during the exercise. (U.S. Air Force photo/ Senior Airman Ethan Morgan)