Scotland Yard has admitted that a man shot dead by police hunting the bombers behind Thursday's London attacks was unconnected to the incidents.
Police cordoned off the station after the shooting
BBC correspondents Gordon Corera and James Hardy look at the implications.
Q: Will this have an effect on attempts to foster good community relations?
The issue of community relations lies at the heart of this situation.
Since the 7 July bombings there has been a lot of emphasis by the police on the need to maintain community relations as some of the best intelligence comes from these communities, and because of fears of rising tension.
There had been some concerns from minority communities - especially Muslims - about the incident at Stockwell, even before we knew he was not connected to the inquiry .
Now we know, there is likely to be even more concern about what some people have termed, a "shoot-to-kill" policy.
It is a loaded term, but tensions are likely to rise because of the incident and because of the revelation that he was unconnected to the inquiry.
Q: What impact will it have on the way the police investigate into the bombings?
This is going to be very, very difficult for the police, but the threat of suicide bombing means these are very different times to those they have faced in the past.
The police have been looking at tactics to deal with this kind of situation for a few years now, but those tactics are going to be under even more intense scrutiny.
It is a sign of this whole new environment that the police, the security services, and the general public are now operating in and the new tensions that will create.
Q: Are we sure police officers were responsible for the shooting, and what is their policy in such cases?
It was definitely the police who were involved in the shooting, but it is not quite clear which unit.
For a number of years the police have been looking at which tactics can be used in the eventuality of suicide bombers operating in the UK, and it is a very difficult thing to cope with.
The police do not make their exact tactics public. There is a broad policy that if officers feel there is an imminent threat to the public or themselves, then they are entitled to open fire, but their exact tactics for dealing with specific situations are kept confidential.
It is not clear whether these officers would have been authorised to shoot whenever they felt it was necessary or whether they would have to call in a senior officer at Scotland Yard to get that authorisation.
All of those issues will be looked at in the internal and the independent inquiries.
Q: Does the shooting represent a setback for Prime Minister Tony Blair?
Tony Blair is content to let the police launch its own investigation to see exactly went wrong in this case.
Number 10 has also reiterated its support of the security services and the police in this difficult situation of trying to trace the bombers still at large.
But this is the last thing the prime minister needs at the moment.
He is going out of his way to stress the importance of close community relations and get the police working to try and bring everybody together at a time when the attackers appear to want to try and divide society.
The last thing he needs politically is for an innocent man to be to be shot, and to be shot so publicly in front of so many horrified witnesses.