Petty Officer 1st Class Jon Palmer, a maritime enforcement specialist from Coast Guard Station Niagara, N.Y., searches the hallways at Coast Guard Sector Buffalo, N.Y., for an active shooter during an exercise held at the sector Jan. 29, 2015. Law enforcement teams worked together to clear the hallways and rooms of the building during the exercise that simulated a real-life active shooter event. (U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Laughlin)