I think the police are generally supposed to have a bit more to go on than "looks a bit like the criminal" before they start arresting people! I think they should also have a bit more to go on than "was named by a single informant who was basically bribed and/or threatened", if what that lawyer says is true. As I said, I can understand the fear of missing a genuine tip-off amongst all the baseless ones, but surely a theat this serious needs more thorough investigation and a better use of resources.