First off, great job in being involved in this guy's life. He really needs people like you to help him get on his feet and recover.
I'd say introduce him to a recruiter who has a lot of connections and can get something going for him. If that doesn't pan out, perhaps some biz owner here on HN might hire him.
It probably depends on exactly what the crime was, but bank robbery or fraud are going to be tough.
(I'd be ok with hiring someone with a manslaughter conviction or other thing if it were not calling character into question. Or, something like a principled hacking conviction would probably be ok in most roles, although clients often care about felony status.)
I'd say introduce him to a recruiter who has a lot of connections and can get something going for him. If that doesn't pan out, perhaps some biz owner here on HN might hire him.