Shoot to kill tactic developed after studying the methods of suicide bombers
The series of strategies that include shooting suspected suicide bombers in the head have become some of the most controversial police tactics.
In the aftermath of the terrorist attack on the 11 September 2001, a Met team visited Russia, Israel, and Sri Lanka to investigate suicide terrorism. The police studied how common types of devices are made and worn, and intelligence- gathering practices.
Scientists said baton guns, Tasers, or firearms could cause devices to explode. The police were also told suicide bombers would detonate devices if they believed they had been identified.
The most controversial tactic adopted is the shooting in the head without warning of a suspected suicide bomber. This is lawful if it can be shown "reasonable force" was used to prevent a crime.
A new command structure has also been designed in which specially trained senior officers, acting as the "Designated Senior Officer", commands these operations. It is the DSO who gives the order to shoot. There is always a DSO on call. This policy was adopted throughout the UK in January 2003.
But it was not until the killing of an innocent Brazilian on 22 July that the tactic became publicly known.