Hell no, not a chance. Your wife's complete illogic in this situation is a very bad omen. If he screws up, your wife is probably going to bend over backward to help him out. You could be stuck with him in some way or another for years. Best to never to provide a chance to let any of this happen in the first place.
I banned my BIL from my house permanently after a few week stay, just because I think the guy is a freeloader and a loser. The guy doesn't drink these days and has never been in prison, but I just think he's a bad influence in general, so I put my foot down despite pleading from my wife and even his parents. And my house is way, way bigger than yours. In your situation, I'd probably wouldn't even let him in the house for a visit, or at most I might let him come by for Xmas dinner or something and that's it.
That may not sound very charitable, but my kids come first.
BTW, I don't like guns and won't have one in the house, but this time having a gun in the house may have helped you.