Petty Officer 1st Class Craig Case, from Coast Guard Station Niagara, N.Y., stands guard in one of the hallways of Coast Guard Sector Buffalo, N.Y., during an active shooter exercise Jan. 29, 2015. Case was part of a five-man Coast Guard law enforcement team responding to the active shooter during the exercise. (U.S. Coast Guard photo by Petty Officer 3rd Class Lauren Laughlin)