I don't believe in warning shots, and I don't believe in threatening, Personally I would have retreated and took up a good defensive position and awaited police response, if they came through the door, well then its time to act, act hard and fast make it all count. At the most on initial contact, told them in no small way to leave my property, police are on their way. Then back in the house, lock the doors, keep 911 on the phone, putting shots into the ground impresses no one, and achieves nothing. I don't think he deserves jail time, but does need someone to take him aside and ask, WTF were you going to do?? He was escalating, not deescalating, I am not going to take on 20+ individuals in my front yard, with any weapon, hide and watch and wait. Hide behind hard cover.