Oh my goodness.

You needed to make some changes years ago but the good news is it's really not too late.
You're going to have to have balls of steel though.

Children whose parents let them get away with all kinds of unacceptable behaviors, skipping school, violence and disrespect, drug abuse...grow up thinking nobody gives a rats ass about them.
To them it appears that they must not be worth the effort it would take to correct them.
YOU AND YOUR WIFE have created a monster.
His mother is the primary culprit but make no mistake, you should have put your foot down YEARS ago.

DO IT RIGHT NOW.

If that means kicking his little butt if he bows up and takes a swing at you, so be it.
Now I don't mean kick his butt like you would another man, I mean you PHYSICALLY STOP HIM from continuing to react violently at that moment.

I'm not sure what you mean about your wife wanting to get rid of him.
I assume you mean putting him in Juvenile Detention.
Well, let me tell you that has about a snowballs chance in hell of bringing out any redeeming qualities the boy possesses.
More than likely, you will lose him to the other hoodlums already IN the system.

The only question at this point is how willing are you, how dedicated would you be, to helping him save himself?