U.S. Army Engineer Research and Development Center security guards review operations during active shooter drills at the Department of the Army Security Guards Mobile Training Team Train-the-Trainer Course held on the ERDC-Vicksburg main campus, February 3 - 13, 2020. The course, the first of its kind at ERDC, was designed not only to train guards in their duties, but also to teach them the skills necessary to pass that knowledge on to their peers.