Sir John Stevens, the commissioner of the Metropolitan police, said the law needed to be reviewed in the light of the threat from terrorists faced by armed officers.
He made his comments at the successful conclusion of peace talks with members of the force's SO19 firearms unit, who had vowed to down weapons in protest at the suspension of two colleagues involved in a fatal shooting.
Sir John said: "We need to have another look now at where we are in terms of protection for officers in the use of firearms. Since September 11, of course, we are having to handle the possibility of suicide bombers and suicide attackers attacking London. We want to have another look at where we are with officers and the use of firearms since September 11."
The home secretary, David Blunkett, last night promised to examine the issue. He said: "We will, in consultation with the police and the other criminal justice agencies, review the way in which shootings involving police are handled - including looking at how the law in this area operates."
The row between the Met and its most highly trained firearms officers had threatened to leave security in London seriously compromised.
Inspector Neil Sharman and PC Kevin Fagan were suspended from duty on Friday after a coroner's court decided that they had unlawfully killed Harry Stanley, 46, when they shot him dead in 1999. The officers mistook a table leg he was carrying for a shotgun.
More than a quarter of the 400-strong unit had agreed to down weapons by Tuesday evening, claiming that the decision threw all police firearms training and tactics into doubt.
The Met's top brass worked quickly to get the officers back on side.
Sir Ian Blair, the deputy commissioner, said the case "brings home the difficulty of balancing the protection of the public against the horrors of gun crime while playing fair by the police officers who risk their lives".
He said that as part of the review of murder law, the government should look at ways of offering more protection to officers who killed in the course of duty.
Sir John met members of SO19 and the Police Federation yesterday. Outside Scotland Yard he announced that the firearms officers - who have now ended their unofficial "strike" - were returning to their duties, "putting the safety of Londoners and their fellow officers ahead of their own concerns". He said the suspension of the two officers would be reviewed, but stressed the inquest's decision could not be ignored.
Sir John, who is to send Mr Blunkett a detailed report on his concerns and those of his officers, said: "The bottom line is police officers who have firearms obviously must be subject to the law like everybody else, but it does mean that if they are acting lawfully protecting themselves and members of the public and acting in good faith, with reasonable knowledge, then surely in those circumstances they require a certain level of protection." The commissioner also expressed concerns that it had taken so long for the Harry Stanley case to be resolved.
Mr Blunkett agreed, describing the delay as "deeply unsatisfactory".
However, Daniel Machover, the lawyer acting for the Stanley family, expressed concern that the review would be carried out by Sir Ian, though he had spoken out for the suspended officers.
