I think even if you ban guns, will it not be able to be bought in the black market?
It's like drugs, it's illegal but you can't get rid of it.
So those are the only solution, ban all guns and be faced with a black market or just have everyone a gun to defend themselves. Because maybe if everyone at the club had a gun you might have had less dead.... Or maybe more we don't know. But any option you take it won't be as easy as people paint it to be.
I personally would like to see how it would go if everyone had a gun.....