Members of Biloxi Police Department's Special Response Team sweep through a room during an active shooter exercise at Keesler Air Force Base.
Bilox PD's Special Response Team is a Special Weapons & Tactics (SWAT) unit.
SWAT teams are trained to respond to crisis situations outside the capabilities of regular police officers such as active shooters (shooting sprees / workplace shootings), high risk warrant servings / arrests / searches, riot control and VIP protection.
As shown in the photo above, civilian SWAT teams may also be called on to respond to crisis situations at military installations.
In such scenarios they will operate in coordination with that installation's in-house security forces which may include military police SWAT teams such as Air Force Emergency Services Teams.