Now, Now, Aren't bars, even in AK, gun free zones. And is the shooter legal to purchase and possess a firearm?
If not, there you go, just ask AK to pass a law making illegal to take a gun in a bar, and illegal to hit people in head with a gun, and illegal to shoot people. Problem solved.
My solution is what sounds like yours. one 9mm in the head. GUARANTEE he'll NEVER break another law or harm another person.