to police officers and members of the public. In extreme situations, the policy recommends that covert police officers fire on suspected suicide attackers without warning, aiming multiple shots at the brain stem to minimise the risk of detonation of a bomb. The Metropolitan Police and other forces also issue Kratos officers with hollow point ammunition, but this has not been incorporated into national guidance. 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. London bombings and the de Menezes shooting After the London Tube and Bus bombings of 7 July 2005, an internal email was sent to specialised police units reminding them of the secret tactics for dealing with suicide bombers. Operation Kratos was first described publicly in an article in The Scotsman on 15 July 2005. Between 21 July and 5 August, Designated Senior Officers were alerted on 11 occasions, with Armed Response Units deployed to 6 of these incidents. On one of these occasions, they opened fire. In the evening after the attempted 21 July 2005 London bombings, Specialist Firearms Officers supporting the search for the bombers were issued with hollow point ammunition. When police linked Hussain Osman and another suspect to a block of flats in Brixton, the block was placed under surveillance. Commander Cressida Dick, who would also act as Gold Commander of the operation, was appointed as Kratos DSO. The firearms team were informed that they faced suicide bombers, that a DSO was in place, and that they might be required to use "unusual tactics". On the morning of 22 July, surveillance officers believed that a man leaving the flats might have been Osman. In fact, the man was Jean Charles de Menezes, who had no connection to the bombers other than his home address. As the firearms team was not at the site (for unknown reasons), one of the watchers followed him onto a bus. de Menezes's innocent actions were misinterpreted as counter-surveillance measures, and a firearms team