The decision whether to take such drastic action would be made by a Designated Senior Officer (DSO), an officer of Commander or Deputy Assistant Commissioner rank designated for that incident. The Met had previously used an on-site Designated Senior Officer in policing the Notting Hill Carnival, to decide whether to employ baton rounds should a riot develop, but the situation never arose. To deal with the more severe challenge of suicide bombers, Kratos DSOs would be centrally located, and would be available at all times.