Hunting him down will push him further underground and his support will close in. He knows you are looking for him and will call on his mates to protect him.
I can assume he has run away as he is unhappy with how things are at home? I don't want to drag your personal stuff in the public arena, but maybe try a different approach.
Is there a friend of his you can talk to who can pass on a message to mediate, maybe see if you can meet him at a neutral place, or initiate a phone call, even if for now to establish he is ok and work on it from there.
Without knowing what is really going on though, it is hard for me to offer solutions.
Hang in there.