Leading article: How to forfeit the public trust

At the heart of the matter is the question of why police used such lethal force. Before the 7 July suicide bombings on the London transport system, armed police officers followed some straightforward rules. This was itself a result of some high-profile mistaken shootings in the past - such as Stephen Waldorf and Harry Stanley. Officers were required to identify themselves to the suspect. They were to aim for the torso. And they were to reassess the situation after each shot.

None of this happened in the case of Mr de Menezes. This is because after 7 July, the Metropolitan Police's Anti-Terrorist Branch established Operation Kratos, based on the experiences of the Israeli security forces. This stipulates that officers should shoot suspects in the head if they are believed to be suicide bombers and pose an imminent danger.

It is nothing less than a shoot-to-kill policy and constitutes a fundamental change in policing. And the police should not have implemented this without announcing what they were doing. The authorities are entitled to argue that the only way to deal with suicide bombers is bullets to the head without warning - but the public should have been given an opportunity to challenge them on this point. The decision must now be subject to proper democratic scrutiny.

Some have taken the view that, faced with the threat of suicide bombers, armed police should have maximum leeway to use their discretion. But this is quite wrong. The police themselves must be subject to the rule of law and follow agreed procedures. More fundamentally, we must ask whether a reflexive shoot-to-kill policy is more likely to result in an innocent person being killed than innocent lives being saved. In the wake of the tragic case of Mr de Menezes, it would seem that the risks associated with this policy are simply too great.