This isn't a theory on who Red John actually is, but I actually think that Teresa Lisbon might be a Red John accomplice. I know this theory is way out there, but imagine what an amazing twist that would be. All the troubles Patrick Jane has gone through trying to catch Red John but fails every time, and it ends up that he hadn't had a chance from the very beginning, or even him knowing she has been part of Red Johns "crew" this whole time! I don't know why I want this to happen so much but I personally think it would be awesome for her to end up being an accomplice of Red John. (Just my opinion please don't be upset with me, and sorry I couldn't find proof to support this. Please don't spoil the show for me I have only seen up to season 5 episode 4. Thanks!)