So this is not an elaborate theory, just some thoughts.

I think that it's suspicious that Stiles is the only suspect that we haven't seen this season. I'm not certain that he is Red John but I believe that Red John was a Visualize member at one time, or still a member. It's possible that the "tiger, tiger" conspiracy group are all Visualize members. I believe the next episode is about a murder at Visualize, I wonder if Stiles is the next Red John victim?

When considering that Bob Kirkland asked every victim "have you seen me before? Are you sure?" before killing/torturing them, I believe that Bob suspected his twin brother of being Red John. He told Jane that his brother was drinking and got sucked into a cult (Visualize) where he later became a prominent figure in the cult, mastering the con arts of manipulation and brainwashing.