Looking at the crappy video

 Where the bad guy tried to assassinate those two cops sitting in their cruiser...

The perp plants his feet, brings the pistol up to his sight line, and doesn't hunch his sight line down to the pistol, and uses a two handed grip.  Decent form.  

The adrenaline is still coursing through him, and you can tell with the furtive fleeing.  He get's headshots, but it seems his accuracy sucked (thank goodness) and his victims survived.  Why did his accuracy not tell worse?  Guessing.  Adranaline, again, rushing himself, very little lifetime target practice.  But you don't get the stance and grip right by not working on it.  Evidence here is he worked on that.  Hollywood didn't train him.  Someone may of told him, "Naw, do it like this," and he may well have drilled it a time or two. 

The gun community has little respect for the gun handling abilities of gang banger types, but you underestimate these bad buys at your peril.  It wouldn't have taken much range practice to make this particular perp much more deadly, is what I am thinking.

A total bodger can shoot you dead, too, with only a touch of luck.