When there is a high profile attack the police often say that, as far as they know, it is not terror related. This seems to be a standard procedure. I have a couple of questions about this. Firstly, why do they do this? Is it to re-assure the country that they are not anticipating further attacks. If so, that seems sensible to me. And then my other question, how many times have the police said it isn't terror related, but we found out later that it was.