Don't go chasing people down shooting at them. There's no reason for it and at that point the cops were preventing an attempted homicide. Sad for the store owner that he is critically injured because of a couple of scumbags but there's no flashing good guy beacon in the real world to tell the cops who's who. Someone posted a video of an officer being slaughtered by a man with a rifle I've seen it before and if you haven't is absolutely horrifying. I can't fault an officer firing on an active shooter outside in public view.
Remember you are shooting to stop the threat, be it making them DRT or at the point where the bad guys are outside in a vehicle fleeing they are no longer a threat.
Remember you are shooting to stop the threat, be it making them DRT or at the point where the bad guys are outside in a vehicle fleeing they are no longer a threat.