Leading article: A tragic death that continues to raise questions about the police

The initial response in this country to the news a week ago that the police had shot dead an innocent man in the mistaken belief that he was a suicide bomber was shock and bewilderment. But now those feelings appear to have hardened into anger in some quarters.

Why, it is asked, was it necessary for the police to shoot the suspect? Yasin Hassan Omar, who was arrested in a police raid in Birmingham in connection with the failed 21 July bombing, was incapacitated with the use of a non-lethal Taser gun this week. If the same technique had been used on Mr de Menezes, the Brazilian would still be alive today. Or so it is claimed.

The Metropolitan Police Commissioner, Sir Ian Blair, has a simple answer to this. He points out that a Taser works by delivering a powerful electric shock to the body - something that is very likely to detonate a suicide bomber's explosives. But this raises the question of why the West Midlands Police used a Taser on Omar. Sir Ian Blair has offered no answer to this. He suggests, "It may have been that they were clear there wasn't a bomb. I don't know what the situation was."

The Commissioner is probably correct in his analysis that the use of Tasers against suspected suicide bombers is not feasible. But is it not rather disconcerting that he does not know the details of the Birmingham raid? This admission raises legitimate questions about the lines of communication within the police's anti-terrorism operation. However, it is worth reasserting a few things with regard to the tragic death of Mr de Menezes. This was not, as some have wildly argued, an act of "state murder", or "police terrorism".

The officer who shot Mr de Menezes was faced with a truly awful situation. He had to make an instant decision - whether to hold fire, and potentially see innocent people die in an explosion, or to kill the suspect and risk being responsible for the death of an innocent person. To suggest there were any considerations in the policeman's mind other than preserving life is irresponsible and quite reprehensible.

If there were any inexcusable mistakes made, it would seem to have been further up the police chain of command. Why, for example, was Mr de Menezes not apprehended before he entered Stockwell station if he was under surveillance? And why was he allowed to board a bus, if the police thought there was the slightest chance he might have been a suicide bomber?

Such questions will have to await the inquiry into the incident being conducted by the Independent Police Complaints Commission. So too will problematic questions such as whether Mr de Menezes vaulted the ticket barriers and whether the police vocally identified themselves to him. (Incidentally, of all these, Mr de Menezes' immigration status would seem to be the least relevant.)

It is healthy for a society to demand answers, especially when its police forces apply lethal force. The task for the police is to do everything possible to minimise the chances of something as dreadful as the death of Mr de Menezes occurring again. But it is equally important to bear in mind the deadly context within which those who protect us are now working.