So I am several seasons behind and just now catching up.  So while I am watching season 3, I see a particular episode where Gale Bertram quotes I believe it was Faulkner (some poet) at a crime scene.  This is a continuous theory and point for several episodes, about the "tiger, tiger" poem.  Now I am about halfway through season 4 and during the episode ( I think it's 16 -18)  Bertram talks to Lisbon asking for an update.  After she leaves, Kirkland emerges from a room behind Bertram. Kirkland asks Bertram if they think they can trust her; Bertram responds "can we trust anyone".  Now we know that there is a connection between Visualize and RJ and of all the connections, you never see Kirkland with any one of them.  However, this past episode, Behind the Red Curtain, Kirkland asks J. Lennon if he recognizes him and Lennon says no and even still, Kirkland kills him before Jane can even see him.

So either
1 )Kirkland and Bertram are confederates of Red John,
2) One of them is Red John OR
3) they are part of Visualize OR
4) they are part of an investigation into Red John.

Bertram I don't think is RJ simply because he is easily manipulated and not clever enough to be conscious of his own tells during a poker game.

Kirkland is an enigma and that is what I expect RJ to be.  Though I'm not completely convinced he's RJ.

Stay tuned....