I'm going to throw the old felony murder rule out to see what the splatter sticks to. If a shot at the nutjob misses him and hits someone else there is a good chance the prosecutor will try very hard to make the nutjob legally responsible for any injury caused. That does not resolve the moral or ethical issues, but sure does do a lot to lessen the chances of winding up sharing a cell with the nutjob.
Do y'all remember the stunt one of the TV networks pulled a little while ago, giving a gun (OK, so it was an airsoft fer crying out loud) to someone who had little idea of which end the bullets came out of, dressed them up in a baggy sweatshirt at least 7 sizes too big, and stuffed the airsoft into their pants with some cheap, floppy nylon IWB holster, and then had them try to take out an active shooter in a small classroom setting? Even then the folks who were not playing active shooter or "Our Hero" tended to drop to the floor as opposed to standing tall and sprinting for the exits. From what I have read and heard, that's what most of the folks in the theater did until the shots stopped. Part of it may be (my reading between the lines) because the aisles were jammed even though there were not a great number of folks trying to use them, and folks were getting hit there moreso than were those hiding behind the seats.
Moving on - the situation raises a large moral dilema for me. Why should I be responsible for saving the backside of anyone who is not willing to assume any responsibility on their own for trying to protect themself? Add to that the usual list of attendees at any given movie theater, and a midnight screening especially, and I become hard pressed to see why I should want to save their backsides at the risk of my own.
Someone riddle me that, please.
stay safe.
