Most people believe that Kirkland being red John is to obvious, but I'm a firm believer of Occam's razor. Every time we see Kirkland it's related to RJ. The first time we see him is in the flashback which shows he has been watching over pj during his whole CBI career, when he meets and SHAKES pjs hand the red John theme plays in the background, plus he is shown killing of an RJ accomplice and he also got himself all of James RJ research which whould explain how RJ knew the seven names. He is creepy and intelligent which are defiantly two personality traits RJ whould have. I'm 99% sure this guy is RJ but heller is that brilliant you just never know.

  " You Think You're Very Clever...I'll Show you Clever "

1.-My Name Is bret Partridge,I'm Red John.When I Made The List Of The 7    Suspects I Put 6 Others Before My Name,I'm Not Stupid Enough    To Put My Name First...    Clever ?

2.- " Hello Mr Yardley,Who Did This To You Mmm ? ( I'm Expecting  A Reaccion From You Mr Jane )     " You've Been Really Sullen With Me,And Now you're Staring At Me     Stragely And I Don't Know Why "  ( What Is The Matter You Don't    Want To Play Mind Games Anymore Or Should I Show My True Self    As Red John And Play Some More. )3.- Teresa-What's Your Take On Partridge?      Jane-If He Is Red John He Is A Very Good Actor.    Teresa-He Had To Be,Wouldn't He ?
4.- I bret Partridge Staged My Own Death In Order To Capture     Teresa Lisbon And Take Myself Out Of The Suspects List.    Because I'm A Showman,And Artist And I Have A Strong Sense Of     Theater.I As Red John Will Make It Look Like My Body As     Bret Patridge Was Taken Away By Me Red John By The Time    Teresa Lisbon Wakes Up...And You'll Have No Choice    But To Belive Teresa Lisbon tHAT i Bret Partridge am Dead.5.- Killing More Often And Get Away With it...That's Not Clever....    Faking My Own Death....NOW THAT'S CLEVER.6.-One More Thing,There's Something I Left By The Sink,   Something I Use When We Have Our Satanic Rituals....   Tyger....Tyger Burning Bright...Something We Say   On Our Rituals...But You Won't Know That...'till   Next Time....We're Face To Face....

First of all, I'm uploading an important image below in the comments, showing a comparison between the back shots of Rebecca's killer and Haffner. And also proposing a theory as to how RJ got the info on Aileen and her connection with Jane's memories and also the whole Loreli, RJ's List ordeal.

For most of the time Bertram has been at the top my list and so has Haffner. Since they both can be Red John I'm going to explain why the either can be RJ.

Haffner

1. Fit's Rosalind's description quite well except for the voice (although RJ has to be faking that pitchy voice, he wouldn't make such a silly mistake).

2. The visualize connection, and they "screwed-up kid" remark and the whole thing in The Red Barn episode where he tries to manipulate Lisbon.

3. He is an ex FBI Agent (that explains RJ's connections in the FBI) and ex CBI agent who specializes in Creative surveillance techniques. Which means he has the skills and resources and the intelligence to hack the CBI Network (while attacking Bosco's team or when Jared Renfrew escaped or when He followed Darcy and in this episode as well.

4. The handshake and more importantly his demeanor during his first appearance. He seemed a little friendly towards Jane, no? As if he really admires him on some level and was glad to be finally able to get a chance to spend time with Jane. And the through out the episode where he show's his manipulative and inquisitive side.

5. Consider looking up the personality traits of a psychopath and compare these guys with that. Both Haffner and Bertram do seem to have some of the traits. (Of course Jane has been diagnosed in the show as a clinical psychopath, but I think we can exclude Jane and just spare him of that accusation :) )

Bertram

1. Did shake hands with Jane, and called him "Boy wonder" as he was called in his early days.

2. His involvement in the RJ related cases such as the Todd johnson murder, Hightower frame-up and Loreli Martins.

3. Just like Haffner, Bertram too behaved in a friendly way with Jane initially and did say that he admired Jane's skills.

4. He's the opposite of Rosalind's description. Now think about this - RJ has killed everyone who can identify him except Rosalind (and the little girl Haley too). So why not Rosalind? She already gave his description way back in season 1? He must keep her alive because she hasn't broken his trust by giving the CBI the wrong description! She said Roy is just under 6 ft tall, Bertram is the opp - as tall as 6.2 or 6.3. Has short straight hair and Bertram - BALD :P. Not muscular but still strong (Well he is that) and the voice - which as I explained above, is fake.

5. I read a theory on this site somewhere that the "He is MAR..." message could actually be Renfrew writing "BERTRAM" in REVERSE, which would have been MARTREB. I really liked this and this supports my theory well. Cudos to whoever wrote this theory! :) 

6, In the latest episode, Bertram says he know's about Jane getting closer. But At that time, only Teresa, Patrick and RJ knew that Patrick got closer. Cho and the guys didn't even know! And the way he talks to them and the line where he says i am many things to many people, doesn't that remind you of what Timothy carter said after BERTRAM left him and Jane alone at the mall?!

Now finally, a theory about how RJ could have come up with the list just like Jane's and also know about Aileen

Either Bertram or Haffner, could have kidnapped or somehow in the past have been in contact with and gotten the info about Aileen from people who could know about Jane's childhood. And there are 3 people who could possibly know that - Alex Jane, Sean Barlow and Dr.Sophie Miller (if I got her name correct).

Now we've all seen the way Bertram approved Kirkland access to the RJ investigations. This almost seems like him cleaning up his mess and not getting his hands dirty. Which also means the the mysterious Mr.Kirkland is actually an associate of RJ. That explains why he asked Lennon if he knew him and not RJ and still killed him and said that thing about having a friend who would do this for him. IT just means he's doing the dirty, risky work for RJ.

And about the list, I'm sure that Patrick has a different list and RJ has a different one. And that's because Jane suspected a break-in and that's what happened. And as we know who broke in we can say that the real RJ, either Bertram or Haffner has been given the wrong info by their associate Kirkland.

I hope my theories have interested you and if you have and complaints/suggestions/criticisms/corrections, please let me know! :)

And don't forget to check out the picture I'm uploading below in the comments!!

Am I the only one recognizing the voice of Brett Partridge?The one who calls Patrick in the end,  has the voice of Brett Partridge!!  go check it out, and then continue with your theories.

If red john did not kill lisbon when he captured her then there has to be a reason for doing so. Red john would kill anyone that is somewhat close to patrick jane. So for not doing so to Lisbon makes me think does he have anything towards her? Season 5 episode 13. Ray haffner talking to Lisbon and wanting her to move out of her current job where he is located and shows hints of him kind of jealous of how she wanted to stay with Jane. I feel like he likes her and for that reason he didn't kill her, therefore red john is Ray. I Hope this makes sense..