If he's waving a gun around he's a threat, If I get an opportunity to shoot without endangering others I will do so.
If the situations escalates, he fires the gun, starts taking hostages, or moves towrd me. I will engage him.
Problem here is there is a good chance of injuring an innocent bystander, if you start a gunfight. Thats the last thing I would ever want to happen.
Lastly if he's fleeing the scene without firing a shot I would let him go. Once again remember that every bullet you fire will have a lawyer attached to it.
