For everyone out there that thinks Red John is  'many,' it does not matter. Jane wants the person who killed his wife and daughter, which is only one person. He will probably bring Red John's associates to justice. If Red John consists of multiple people, then I would want to know the one person who killed his family more than the multiple people that make up Red John.

I really love theories on this site,they were very few bad theories abouth who Red John is( Van Pelt,Lisbon,Cho,Rigsby,even Jane himself...those were really bad theories) but now I see a whole bunch of Michael Kirkland theories and I am sorry guys but this one beats all of them...it is the worst theory ever,making Red John someone we have heard about until 6x4...come on,if Michael Kirkland would have turned out  to be Red John it would be the stupidest ending of all time...I am really surprised how many fans this so called theory has because I see a lot of plausible hits on that kind of theories.

With the list ever dwindling, it is quite obvious that RJ is Bertram.  Outlined below are my reasons why.

1) It all goes back to the end of season 3 and revealing the Mole. Heller said we would see RJ face and if it is Bertram then that statement was accurate

2) revealing the mole actually proves Bertram is red john as well.  Betram and Craig O'Laughlin (COL)  are both suspects  as the mole and hence both told different room numbers where Hightower is staying. COL tells Bertram what he knows  and thus he realizes it is a trap.  He knows how smart Patrick is and he will figure out the reason the hired hit man has the rope. Therefore Bertram sets up COL and thus takes the focus off himself at the same time. 

When meeting in the Food Court, Timohty Carter is called in to be "red john"  and have Bertram's back. Otherwise how would he know to be at that exact place with a gun....  COL couldn't have told him cause he didn't know Bertram would be there. 

3) Moving to this season, the reason he doesn't kill Teresa in the opening episode is quite simple.  The Jane - Red John dynamic is all a delicate game of chess. Bertram knows the kind of relationship Lisbon and Jane have (review the Jane-Bertram conversation in S4E2) and if he kills her, he is not sure the effect it could have on Patrick. If it takes him "out of the game" so to speak like it did when he killed his wife and child, it ruins the relationship RJ wants to have with Jane.
 
4) Bertram has told Jane he wants to be there when he reveals RJ - why?  Simple, it is the final move in their game of chess. If Jane is right and confronts Bertram.. he wins the game. If Jane is wrong and confronts someone else, RJ wins and Bertram is there to live in his glorious moment.

SPOILER AHEAD




5) Rumor has it that starting in episode 9 after Red John is killed, the story moves 2 years in the future. There's been a thorough house cleaning in California Law enforcement as a result of the vast conspiracy led by Red John. . What could cause a bigger fallout than a notorious serial killer leading the California Bureau of Investigation?  It all points to Bertram.....

anyway that is just my take on it... I would be really surprised if it is anyone else other than Bertram...

     Here is my thoughts , here is my theory....
                     Please Read it...

  After the last episode , it's obvious 3 suspects had a tatoo on their left shoulder and the three are "good" whistlers ; those suspects are Gale Bertram , Reed smith and Sheriff Thomas Mccalister.
 
    We begin with Reed smith the unlikely suspect:
 - He is fat , doesn't fit any descriptions  and didn't appear in 4 first seasons, even if Bruno heller tries to make him suspicious, especially in the last episode but no way, he can't be RJ.
 
    And now Sheiff Thomas Mccalister is a good one , smarter. sometimes he appears alike Jane.

  The last One Gale Bertram he has many friends , he is a showman , Good posture , good speaker , high law enforcement.

   There are two things from the last episode that we should discuss it :
  
   1)  Gale Bertram after the discussion with Jane and Lisbon about closing in on Red John  , he makes a call, he said : " Yes, it's me , i had a very interesting discussion with patrick jane "

     =>  He calls a person who knows him , and who wants to keep informations about RJ. We don't know whom this guy. We should discuss that point.
.  
      2) Why Brett stiles cares when patrick wants to shoot Sheriff Thomas mccalister , and Stiles asks Patrick to see others two whom had the tatoo too :
     
     Did he want to protect Mccalister from shot , because he knew Sheriff is RJ , and patrick will shoot him 100% , because he waits 10 years for that moment.?
     OR
     Did he want to help Patrick , because he knew Mccalister is not Red john  and  Reed or Gale is the real RJ  ?
     OR
     Did he want patrick to know about the sign maybe of the organization "Tyger Tyger" , because Vizualize have some problem with them. ?

    Thanks to you all , don't forget to Share your points of view ...