Sorry, I have to disagree with Batman (now there's a sentance I never thought I'd say!)
The man, yes at 25 your son is a man, is old enough to know right from wrong and blaming any problems he gets into at that age on a family breakdown is a kop out I'm afraid.
A vast majority of kids went through their parents divorcing at a young age, me included- I was five, but we don't all end up in court on assault charges because of it!
It's time to stop worrying about him puddicat- he's assaulted someone, and if it all goes pear shaped in the courts for him, he's only himself to blame.
I appreciate you might depend on his 'dig' money, but you can't always be dependant on that can you? He wasn't going to stay with you forever was he? Time for you to look for other means of aquirring extra money, so you're not so dependant on his- and let him suffer the consequences of his actions.