170201-N-OH551-051 PATUXENT RIVER, Md. (Feb. 1, 2017) Navy law enforcement officers from Naval Air Station Patuxent River and deputies from the St. Mary's County Sheriff's Office check equipment and checklists during the Solid Curtain/Citadel Shield 17 emergency response exercise at NAS Patuxent River, Va. Solid Curtain/Citadel Shield is an anti-terrorism and force protection exercise conducted by Navy installations within the continental United States to ensure that the Navy is ready to respond to changing and dynamic threats at all times. (U.S. navy photo by Donna M Cipolloni/Released)