The famous Sheriff Jim Wilson was called to testify in an alleged homicide case. To make his point, he had a bailiff unload his weapon and come point it directly at the sheriff. The sheriff, with his weapon unloaded and sitting on the stand told the baliff to "fire" when he made a move for his gun. The sheriff drew and clicked an empty chamber before the baliff could do anything.
Two things can be learned from this. 1. If you are fast enough, nobody can get the drop on you. 2. Most cops can't shoot for scat. (I personally think this is funny)
Even though it was a movie, John Wayne had good advice in "The Shootist", when he told Richie Cunnigham,"most men will hesitate, I won't."