I think Kirkland is either working FOR Red John (understudy?) or has his on agenda against Lennon, something we don't know about Miranda's/Lorelei's death.

As we know Red John has connections and needs money. This is why I think Kirkland didn't like Lisbon following up on Volker, because he is a source of money for RJ and his antics. I think this money could have funded an appearance change, but I personally think that surgery is unlikely, and the Kirkland and Lennon had history, which will come to light over the next 6 episodes.

I don't think that RJ will be revealed in season 5, but I believes that on discovery on who it is, it will link Kirkland, Visualize, and a mole in the CBI/FBI, and the farm from the past. I don't think its a relation to PJ because the murders at first were not related to PJ until the murder of his wife and daughter; only then it got personal.

A part of me thinks Virgil Minelli could be involved, but unlikely. My bet is on Ron because for those viewers who aren't googling the theories, it would be beautiful.