Last night, they replayed "Red Letter" which was the second episode that Kristina Frye appeared in.  It was also the episode which directly preceded the Season 2 finale and the introduction of 'Tyger, Tyger'.  I've long thought that Kristina Frye will be found to play a role in Red John...perhaps RJ's wife, maybe she's the young girl who Jane conned while in the carnival, maybe she's related to someone he conned when he was a professional psychic years later, etc.

In an earlier theory, I listed a lot of reasons why Fry could be involved...but a new one jumped out during Red Letter.  The CBI was investigating the murder of a wealthy, high-ranking California activist campaigning against human-trafficking.  Kristina Frye was called onto the case before the CBI.   During the investigation, a huge mystery centered around the victim's illegitimate daughter...Carmen.

When the Dr. entered Lisbon's room last week and asked if she was Mrs. Carmen Lee...Jane stopped and obviously pondered something when he heard the name.  Could he be thinking back to this case, and making a connection to Kristina?  To the Sheriff, who bore a striking resemblance (looks, voice, and mannerisms) to McAllister?  To the victim's associates who were obviously well connected within the state?

Kristina Frye first appeared in Season 1, so she's been part of the story since it's inception.

The most obvious suspect is Bob Kirkland. In fact, I think it's so obvious that many of us have gone in a different direction thinking that Heller would never make it that obvious. Then there's the hospital scene. If Kirkland is looking for RJ himself, then why not question him about RJ before killing him? I think that scene is meant to throw us off, while at the same time building the suspense around Kirkland. If he turns out to be RJ, it will be explained why Lennon didn't recognize him, which  could be for a number of reasons. Kirkland could merely be working for RJ, but he has only interacted (on screen anyways) with Bertram, and he seemed to be the higher power in that scene.

Kirkland looks, acts, and sounds like he could be RJ, more than any other of the suspects. Haffner was served up to us last episode, but if you watch his past appearances, he has been outsmarted by PJ, and talked down to by Bertram. In fact, before this season, Haffner had done nothing to make you wonder what he was up to, other than his involvement with Visualize.
Then there is the Kirkland handshake scene. The only one of the seven suspects to have their initial handshake showcased dramatically on screen, complete with ominous music. Finally, Kirkland is one of only two suspects not to have appeared yet this season, which sets him aside for something. We'll see.

This isn't a theory; it's musing...

Key unanswered questions, in my opinion:

If the 1988 killing at the Visualize farm was the work of the same person as the Red John killings since 1998, why were there apparently no killings for ten years?  Was he in prison?  In the military?  In law enforcement training and/or rising through the law enforcement ranks?  Serial killers typically don't just take ten years off.  Why did RJ?  Or did he?  Could the 1988 killing have been his inspiration rather than his handiwork?

What's the deal with Lorelei's bullet wound and her appearance in the list of suspects video?  Something there doesn't add up, and the simplest way to resolve the conflicts is to assume that she's not really dead.  If the video was actually shot much later (with a living Lorelei), it would explain how RJ supposedly got the list before PJ made it.  Namely, he didn't; it was a trick, just like PJ said.  The list was stolen from Jane's office while he slept, the video was made the same night, and given to Jane the next morning.

Why did PJ's daughter (in his hallucinations in "Devil's Cherry") ask him "Does anyone know who you are?"  She could have just meant "Has anyone come to understand you and know the real you?", but somehow I don't think so. The wording seems off for that...

Lastly -- and most importantly -- there clearly seems to be a mole (knowingly or not) who is providing RJ with an enormous amount of info on happenings at the CBI.  And I don't mean Bertram, because it includes even minor day-to-day stuff, and often gets to RJ literally within minutes. So is RJ himself a CBI member, or does he have an accomplice (again, willingly or not) within the team?  It seems like he must...