At the very least if you're gonna shoot at least aim for the legs or arm to disable them so they can be tackled to be arrested. Start shooting to kill all looters then that's gonna make the situation 1,000 worse than it already is or will become. Talk about a riot in that case.
Not a flame, merely an observation. As a person trained by the military, and later on in a career in law enforcement, this is something you would never do.
Not only is it difficult enough to hit your target in general, (after all you are pointing a weapon at them, of course they don't want you to hit them) if the decision is made by yourself to use deadly force, you do just that. Your sidearm, weapon, M-16, whatever is NOT a tool to disable.
The decision to fire your weapon is made if the person on the receiving end is about to utilize deadly force on YOU, if they are an immediate threat to someone elses life, or under orders (in the case of the military). You NEVER shoot to maim, that just lets them get up and attempt to use deadly force back on you.