Two US Marine Corps (USMC) Special Reaction Team (SRT) members (both standing) cover USMC Sergeant (SGT) Mark Thompson (lying prone, left) and USMC Lance Corporal (LCPL) William Papple (lying prone, right), both playing the role of perpetrators who had taken a hostage, during a Force Protection Exercise (FPEX) being conducted on Camp Smedley D. Butler, Okinawa, Japan (JPN). This phase of the base-wide FPEX was conducted so that the Camp Foster USMC SRT could test and improve their base security procedures and emergency situation response time in preparation for a real event