You know what's wrong with that? I've seen it done too many times just as you describe it, on television. If some dumb sob was guilty of something and you said that to him, it seems he would know you were not telling the truth, because they show just exactly that on tv all the time.

I've often thought that tv cop shows educate badguys to the methods of cops. But not being a badguy, I don't know...

I saw a movie where only the military and the police had guns. It was called Schindler's List.