First thing I'd do is visit him in the jail. Tell him that it's time he went out in the world and worked his problems out. Not knowing the situation or any of his other resources I can't opine any further than that. Probably should help get him into some housing of his own and tell him that's it. He is going to have to grow up. He's going to have to have a job and housing in order to make it. other than that, he's just another homeless nitwit running around looking for trouble. Sorry for your troubles. So if he is her grandson what about his actual parents?