First, 16 rounds fired? The officer would have to dump an empty magazine and load a new one.
Secondly, no action of the part of the victim to trigger the shooting? That wouldn't make any sense.
America's gun shop shelves are loaded with pistols that have standard magazines of 15 or more rounds capacity. Glock, Ruger, SIG-Sauer, Smith&Wesson, Beretta, etc. all make them.
And NO, you don't have to be a cop to buy the standard capacity magazines.
The idea that this individual had to reload to fire 16 rounds is ludicrous.
See #41. No reload required for many standard police-issue guns.
The “victim” probably did something to trigger the shooting.
Nonetheless, the cop emptying a full magazine+1 into a perp, who spends most of the rounds on the ground not moving, does seem seriously excessive.
Those looking for an excuse will likely find one in this video.
And the video will likely come out.
Prep, people. Festivities will commence soon.