one or two plain clothed, working the crowd. a lot of people in the audience paying attention to what is happening. then you have a chance to spot something. often times with a lone wolf the first time you notice something is when they start an attack. but if you have one or two officers you can get a quicker respops and reduce fatality and injuries. but the problem is if people want to reduce it to zero, they will minimize the access to people whose job it is to provide access to them. >> mike: morrison, for all of us who see trace of this behavior with our friends, what are the tell-tale signs to look for among those we know? people in the circle of family and friends? >> someone who has had a change of behavior.