It can't be Jane because it would damage the character for syndication. Granted, it might be "neat" & make headlines, etc.; but - in the long run - Jane can't be a serial killer w/o damaging the series' potential revenue in syndication. No one messes with syndication. It's probably someone insignificant so they don't damage their revenue streams.
Red John is Agent Kirkland.
In season 5 episode 18, he kills the witness who knew Red John, and before that he asked him: "Do you recognize me?"
When he is asked by Lisbon in an older episode (season 5 episode 13) if he was at the Visualize farm, he doesn't answer.
He is the only person whom full name is unknown, so it's probable that he is Red John.
Damn, that part "It's ok, I'm here for you. I won't leave you" was sooo Christopher Walken !
Quick notes - no ring on Kirkland's finger ; definitely Jason knew him but couldn't recognize him (only a planted suggestion or face transplant make sense) ; if it is face transplant and that last night really was RJ, than it is safe to say that he assumed Kirkland's identity.
It would be stupid if RJ was an HS agent all along, and he changed his appearance to look like this for at least this last 10 years.
But I don't think Kirkland or whoever that was in Red Curtain is RJ.
This is not a theory about who red john is, but something that I noticed. Bruno Heller is giving all the suspects of being RJ as the theories all over the internet more roles in the past few episodes. My guess is that he is revealing RJ this season.
I believe Red John has been introduced to the viewing audience in another identity.
I decided to look at this as more of a casting issue.
The actor they choose for this character must have "acting chops".
Most likley:
Male
Mid to late 30's
Caucasian
Around 6 ft
Member of visualize.
Has shaken hands with Jane.
He is not often selected on these type of sites, which is odd because he is one of the few characters that meet all of the requirements(that isnt dead yet).
I believe they have selected Agent Ray Haffner, played by REeD Diamond, a Julliard trained actor.
My theory is Kirkland. In the end of the last episode, he kills Lennon. But what's most important is the timing: it was after Lennon woke up from his coma and Kirkland realized that he remembered him. Lennon was the one person that could lead Jane to Red John. Coincidence? I think not.
Kirkland was calm in administering the deadly poison--very stealthy, very cool, very collected. And when Jane got there, his manner did not change.
The words Kirkland spoke struck me: "I'm so sorry. He didn't say a word." Was he sorry? Maybe. But the second sentence finalized Lennon's death and the link Jane saw to Red John.
But the most important clues come right after. With three fingers, Lennon strokes Jane's shoulder as a sign of apology and friendship. But do most people stroke in a semi-circular arc? I see a connection to the distinct three-fingered smiley faces Red John paints after killing a victim.
As he walks away, Kirkland's face is blank, cold, hard, emotionless. It's like he wipes the memory of the death clean off and moves on like nothing happened. It's the face of a cold killer.
Earlier in the episode, Patrick's inside man (the nurse) comments how Kirkland and his partner feel like monsters in human skin. Could it be that they really are? That Kirkland is that monster--that monster known as Red John?
Then, notice how Kirkland's ties throughout the episode are a deep red: the color of dried blood.
And he dresses neatly, and he is well-groomed. Notice how all his killings are neat and have the same attention to detail as Kirkland does in his dress.
And it is that detail and his perfect history of not getting caught, his power and influence through TV shows and more, and his connections within the city would rule out a man in his twenties, and likely any man over 60. Kirkland has a touch of gray in his sideburns and slightly-graying hair. I'd say he's 40 or 45, putting him in the perfect age range for our Red John.
From this overwhelming evidence, we may have gotten a glimpse of our cold serial killer.
The last episode does not mean that Kirkland is RJ. From Red Dawn we know that Kirkland has watched the RJ case from a distance since the beginning. Why is he suddenly getting involved? What changed? Simple answer: Lorelei was arrested. Kirkland does seem to have connections with RJ but it's entirely possible that Kirkland is involved because of his own connections to Lorelei, Miranda, and Lennon. Kirkland only seems interested in the killings connected with Lorelei. He didn't show up for The Red Barn episode because his interest isn't in RJ but in the Lorelei mess.
Let's consider some possibilities:
Kirkland knows RJ and asked him to kill Miranda for personal reasons. Similar to Red John's Footsteps, RJ got one sister and killed the other for Kirkland. Kirkland interferes with Jane's investigation and kills Lennon to hide his involvement.
RJ knows about a terrible crime Kirkland committed. Therefore, Kirkland kills RJ's friends when they surface just in case RJ told them about Kirkland's crime. That could be why Kirkland asked if Lennon recognized him - to see if RJ had told him. Kirkland gets in Jane's way because he knows that if Jane ever finds RJ, then RJ might tell him about Kirkland.
Kirkland is RJ's main friend. The one that killed Rebecca and now Lennon. He'll be the focus of the season final as Jane tries to capture or interrogate him. He asked Lennon if he knew him to see if Lennon recognized him from eight or so years ago when Lennon brought Miranda to RJ and Kirkland was presumably there.
I really do not think that Kirkland is RJ. Please add other plausible theories explaining Kirkland's role.