He got out of the car, showed the first cop the gun. Then he walked another 5 paces, then turned and pointed the thing at him. After pointing, and not having the gun fire, he turned his back, kept walking, and it looked as though he put his left hand on the gun, in what could have been an attempt to jack the slide back and put a shell in the chamber.
I believe this is how the second officer interpruted the action, and fired to prevent the next step, wich would have to wheel around (again) this time firing a loaded gun.
If ever there was a suicide by cop, this was it.
The first cop should have fired as soon as the man pointed the gun at him. He didn't ( i guess) because the 'victim' turned his back right away. (to load the gun?)
Anyway if you wait until he turns around again, it's too late because even if the cop fires first, the perp (tv word

), will get at least 3 shots off before he is stopped by shock, or pain. Unless he gets shot in the head, a determined shooter will fill you full of holes...At that close range, the first cop prolly would have died...