KB, I appreciate your comments! The question.."how do cops know things"....well, this is going to sound strange but I can guarantee woggle bear can back me up. After cops are on the job a while, you get an extra sense about you. You can feel things! You can look into a person's eye's and tell what they are getting ready to do! Most times I can tell when someone is getting ready to run..and yes I have chased several! You get an eary feeling sometime that something just isn't right.....you better watch out. Because someone is getting ready to hurt you! Just as WB said, most cops are scared for their lives because of what they face everyday! Most criminals don't care if they hurt or kill you..all they want to do is get away so they don't go to jail. And things do escalate very quickly..sometime you don't have time to think what to do. If you do your dead! And police are trained to use force(whatever necessary) to counter act an act of aggression until the threat is no longer a threat! Now...that is where is gets fuzzy. Everyone sees it different. I might not see a threat as long as you do or vice versa! And is verbal communication a threat? You bet! If cuffing a guy and he's still trying to fight you and saying "If I get loose I'll kill you", is that a threat that needs more reaction from the cop? You decide?? Sometime you do have to be in the cop's shoes!!