MAYPORT, Fla. (Feb. 2, 2021) Naval Station Mayport Security Response Force member Cpl. Keith Shaheen, right, a civilian patrolman, plays out security protocol with Master-At-Arms 1st Class James Conroy, assigned to Mayport Security Division, during an on-base active shooter drill for Exercise Citadel Shield-Solid Curtain 2021. The exercise is a two-part, anti-terrorism force protection exercise that is being conducted nationwide on Navy installations, Feb. 1-12. The annual exercise is not in response to any specific threat, but is used to evaluate the readiness of fleet and installation security programs. (U.S. Navy photo by Mass Communication Specialist 2nd Class Alana Langdon)