Nope...its an attempt to understand what happened. I think if you want to arrest someone you do it. If you know where they reside ...even better. If you see them leave them leave the house...an ideal opportunity.
ISP,
this is a good topic, and one which people will be talking about for many years.
The reason police don't arrest suspects immediatly is that they are trying to find out information that would allow them to either gain more proof that this person is either going shopping, or going to his mates place to plan the next attack. He was a suspect, not a criminal. He became a criminal the moment he refused to obey the instructions of the police. His whole actions after that moment were more than a little suspicious. People don't do or act what he did.
The police tried to stop him when he entered the tube station, maybe they could have done it a minute earlier. Who knows?
When you are trying to gather more information it is sometimes better to have people under survailance.
What if this ordinary good citizen, of asian decent, was aerested at gunpoint in the street for going shopping? Would the title of this topic be, Police are violating ordinary peoples rights, because they LOOK suspicious........er Why?
steve