The law and the system is dealing with him right now, you save him for what? By the way, I'm a 100% Chinese man, just got back from China after several weeks trip. I type in English only because it's easier.
The point is just simple: for anybody that assaults, just stop it, then let the system handle it. Don't know how to do it? There are tons of ways around out there, really don't know it?
Worry about personal interest? Just move on and build a better life? Is it simple enough?
Sorry, busy, wouldn't talk too much here in the future.