Camp Pendleton -- U.S. Marines with the Provost Marshal’s Office, Security and Emergency Services Battalion, Marine Corps Base Camp Pendleton, participate in a simulated active shooter scenario during exercise Semper Durus 23 on Camp Pendleton, California, April 11, 2023. Semper Durus is designed to improve regional command and control, enhance interagency coordination, and improve installation capabilities to respond to, and recover from, a crisis event and validate the installation mission assurance all-hazard plan. (U.S. Marine Corps photo by Cpl. Wilcox)