Being "Criminally Charged" after a shooting incident depends a lot upon the recommendations of the Investigating Detectives. Being a non-cooperative prick will not make you any friends. And, could put unwanted focus on your behavior. Being cooperative, and promptly responding fully to inquiries...
When it's necessary to bring a gun into the interaction, a small gun, although deadly, may not sufficiently impress your attacker to forget you and go somewhere else. Upon seeing a full sized pistol, which looks like you mean business, may stop the fight without anyone getting shot. So, Look...