Online murder game that then happens in real life.

Hello my movie peeps, I'm looking for something that I saw years ago (within last 15 years maybe older). I'm not too sure if it was a movie or a TV series. The plot was this young man finds an online game (at least he thinks its a game) where you can plot and plan a murder. I think one of the 'murders' he plans was to hide the body in an abandoned train tunnel. He then hears on the news sometime later that a body has been found exactly as he had planned down to every detail. From what i recall a serial killer uses the game for his murders. Thats all i can remember from it I'm afraid. Thanks in advance