Per my post and @Cubs79 - it might be worth knowing more about the context and timing of his crimes before putting him on blast. Maybe he was an 18 year old who had sex with a 17 year old GF, who knows. He may very well be the scum of the earth, he might have been guilty of something a little less disgusting. OP knows the guy well enough to plow his driveway, so there's likely an adult way to start that convo that doesn't involve the phrase 'kiddie diddling'."Hi neighbor, still into kiddie diddling?"
Really, what's the expected outcome on that conversation?