Second Lt. Caleb Alsup, 3rd platoon leader, 411th Military Police Company, 720th MP Battalion, listens to the words of Armando Ramirez, a retired San Antonio Police Department officer and instructor of the ALERRT center, as he provides a Basic Active Shooter training to members of the battalion, as well as local civilian law enforcement agencies March 27 in Killeen. In the last 12 years, the ALERRT Center has trained more than 50,000 police officers nationwide in dynamic, force-on-force scenario-based training.