Can you help me plz I tihnk a kid is in trouble plz help me its very important?

I had a friend name Devin anyway I think he is a pedofile or has pedo behavior he when he was younger like 15 he was charged for well molesting a 3 year old but he got off because they had no evudence anyway.He told me that story and said it was a lie but this weirdo i caught him talking to a 14 year old on world of war craft about like whats her favorite positions.By the way just incase you dont know he is 21 that freaked me out ever sence then i have been weary after that. He told me he cant get caught doing that because he talk to her on a private line on warcraft like on whisper well i dont know really I dont play anyway. that creeped me out waht should i do. oh and one time i told him to stay off some site they might be illeagal he said perosnaly he say check for illegal (suck as child) and he says its not on the internet its actually email through out pedo to their friends.Like take pics in real life and ppost them to their friends tell me what can I do to help