The shooting of an innocent man has raised questions over police tactics and strained the relationship between security services and Muslims. Nick Morrison looks at how a policy of shoot-to-kill is combating terrorism.

FOR Jean Charles de Menezes, Friday was just another day. He was due to fit a fire alarm and had rung to say that because the tube was still not running properly, he would be late. In this, as in so many other ways, he was just like millions of other Londoners, trying to get on with their everyday lives in the face of the disruption and the climate of anxiety caused by the July 7 bombings.

But to police, 27-year-old Jean Charles was a possible suicide bomber. His home was in a block of flats linked to the attempted attack the previous day, when four bombs failed to explode. And this suspicion was enough to make him a victim of the anxiety now gripping Britain.

After he left his flat, Jean Charles was followed onto a bus and then to Stockwell tube station, south London. According to eyewitnesses, when confronted by armed officers at the tube station, he vaulted over the barrier and onto a train waiting at the platform. He fell to the floor and a pursuing policeman shot him five times in the head.

Yesterday, it emerged that his only crime may have been to outstay his welcome. Reports suggested his visa had expired, which may provide an explanation for his panicked reaction when confronted by plainclothes officers.

It may be that the death of an innocent man was an inevitable consequence of the heightened tension in a city where suicide bombing appears to have become not just a horrific one-off, but an ever-present threat. According to Metropolitan Police Commissioner Sir Ian Blair, the policy of "shoot to kill in order to protect", may see more people die at the hands of police marksmen.

But it is wrong to see this policy in itself as a new development in the fight against terrorism, according to Alisdair Gillespie, reader in law at Teesside University.

"Normally they go for the torso, and there is a fairly good chance that if you use a sub-machine gun on somebody's torso they're going to die," he says. "All they're doing now is going for the head instead of the torso.

'IF you have got somebody with a body bomb, the only way of stopping them is to make sure they're dead."

The tactic of aiming for the head has been developed following advice from the Israeli and Sri Lankan police, who have long experience of dealing with suicide bombers, and is part of the Operation Kratos tactics, which have been made adopted by police forces across Britain.

The family of Mr Menezes, shocked at how an innocent electrician can have been killed in this way, have already indicated their intention to sue, but Mr Gillespie says the legal position for the officers concerned is clear-cut.

"As long as they have got an honest and reasonable belief that they need to take somebody out in order to protect the public, there are no legal issues. In this case, he did ignore warnings, he did bolt over a ticket barrier, he came from a house that was under surveillance and he was wearing a quilted jacket," he says.

The suicide bombings represent a threat of a different order altogether to the last bombing campaign to grip the nation, that of the IRA. The IRA usually gave at least coded warnings and, unlike suicide bombers, they had something to lose.

"All the suicide bombers need to do is press a button and it blows. How do you stop that? If you hit them in the chest or grab them, there is a risk they will detonate their bomb. The only thing you can do effectively is take somebody out," Mr Gillespie says.

"The police have got this awful dilemma. Do they not do things like this, in which case you get another 50 people dead, or do they shoot somebody? It is quite conceivable that you will get another one or two people killed in these circumstances."

Rules of engagement for firearms officers drawn up by the Association of Chief Police Officers (ACPO), state that they:

l Must identify themselves and declare an intent to fire, unless this risks serious harm;

l Should aim for the biggest target (the torso) to incapacitate and for greater accuracy, and

l Should reassess the situation after each shot.

These guidelines were introduced following the shooting of Stephen Waldorf in west London in 1983, after he was mistaken for escaped prisoner David Martin.

The number of armed operations authorised by police forces in the North-East has soared in recent years. In the Cleveland Police area it rose from 170 in 2003 to 453 last year, in Durham from 83 to 156 and in North Yorkshire from 100 to 147. Only Northumbria bucked the trend, with a fall from 1,275 to 1,140. But no Cleveland officer has ever opened fire in the line of duty, and a Durham officer has done so just once, to end a siege in Darlington in 1992.

Both Durham and Cleveland forces declined to put up for interview an officer trained in firearms for this article, but in an interview with The Northern Echo two years ago, one Cleveland Police officer spoke of the prospect of using a weapon in the line of duty.

"If you have to wake up for the rest of your life knowing you have taken somebody's life away from them, that is an issue you will have to deal with," he said. "It is something you hope and pray will never happen but it is something you have to consider."

David Blackie, a former firearms tactical advisor for Durham Police, says great care is taken to ensure officers are aware of the consequences of discharging a firearm.

"What I always used to tell people is that if you discharge your firearm, and you do what is required and you do it properly and you get the right result, you will be the loneliest person in the world," he says.

"Everybody will expect you to account for your actions, nobody else can gainsay why you did what you did. It is a judgement call and it always will be."

An officer faced with a life-threatening incident must make a decision, there is no not making a decision, he says.

"If you fire there might be a 50 per cent chance of being right and a 50 per cent chance of being wrong. But if you don't fire, you could be 100 per cent wrong. It is that fine a line," he says.

"Obviously, everybody's sympathies are with the young man who died, but equally some thought should be given to the police officer, who will be going through agonies now."

But the shooting could also affect the relationship between police and Muslims, the very community the intelligence services need to rely on to provide information which could prevent future attacks. Although Mr de Menezes was Brazilian, his death has added to the sense of anxiety many Muslims feel following the July 7 bombings.

Sir Iqbal Sacranie, secretary-general of the Muslim Council of Britain, says that Muslims and non-Muslims must be united in helping to bring terrorists to justice, but that everything possible should be done to protect innocent members of the public.

"While we accept that the police are under tremendous pressure to apprehend the criminals who are attempting to cause carnage on the streets of London, it is absolutely vital to ensure that innocent people are not killed due to overzealousness," he says.

BUT despite these hopes, according to Mr Gillespie there is a real possibility that more people will die as a result of police actions, and a risk that some of those will be, like Mr de Menezes, free from any connection with terrorism.

"If you are a member of an ethnic minority, you don't want to be running for a tube or a train, particularly if you have got a rucksack, and if you are told to stop, then stop," he says.

"If you want to look at it in a callous way, the police have killed one innocent person and the terrorists have ki lled 50. In this case, the police were suspicious because of the way he acted, and if you are heading for 40 or 50 people what do they do?

"Can you imagine if he was a terrorist and he blew up those people and then it emerged he was being followed? There would have been a lot of resignations by now. Could they have done anything else? Probably not."

But while Mr de Menezes' death may have been the result of the tension across Britain after the July 7 bombings, by adding a new dimension to the threat felt by Londoners it has also raised those anxieties still further. The aftershocks of his death may be reverberating for some time to come.