Tolman Bunting.

I'm little surprised that no one actually things that he might be Red John?

Tolman Bunting is played by veteran actor Fisher Stevens (Oscar wining Producer) in episode 18-5-4 in season 2.

He is displayed as very, smart, and to likes games. He is also a Social engineer and Professional codebreaker - something that can give him a lot of conections in high places.