http://www.youtube.com/watch?v=BxJfLgxkyWw 

So we know that Kirkland stole a fake list of RJ suspects and because RJ has the good list i think he is not a suspect anymore so we have only 5 suspects:
- Bret Stiles - Visualize church leader                                                                                           - Gale Bertram - CBI director                                                                                                       - Raymond "Ray" Haffner - private detective and Visualize member, former FBI and CBI agent        
- Reede Smith - FBI agent 
-Sheriff Thomas McAllister - Sheriff of Napa County 

From the "pigeons theory" and the 6X03 episode we know that Sheriff Thomas McAllister "He doesn't scare of high place, like the church's deck, but he hates pigeons, and he practice hunting." Probably he kill Brett Partridge so he is accomplice.

Gale Bertram - CBI director he just doesn't seem like the type. Would be surprised if he was.

Reede Smith -  FBI agent  more likely a disciple than RJ himself. But I don't think he is even that.

Bret Stiles - Visualize church leader  there has been too much that points to him not being Red John. Plus I'm sure they would want to keep him around for after RJ is gone.

-Raymond "Ray" Haffner - private detective and Visualize member, former FBI and CBI agent it's the only caracter that  have been in all the 3 "institutions"(i don't know how to call them) he was in the Visualize at the time of "Red Barn" murders.
-He and Sheriff Thomas McAllister are the suspects that appears only in episodes with the word "red" in the title.
-He shook hands onscreen with Jane.
-Probably is a former football player (like coach Amos Van Pelt, and three of Red John's friends or accomplices: Todd Johnson, Craig O'Laughlin and Manuel Montero). He has an award in his office, lightly similar at the real "Heisman Trophy" (the word "He is Man" are written by Jared Renfrew, with his own blood and before he die at Red John's hands, in Red John's Friends).Maybe He is Heisman like the trophy.
-He's shown to be a good whistler, when leaving Lisbon's room in the Hospital. Important because Sophie Miller stated that Jay Roth (Red John) is an excellent whistler.

P.S Bob kirkland it's a mistery for me because i don't think he is Red John and way he kill that man in the hospitall.I think he will die in the 6X04 episode "Red Listed"

I think its Ray Haffner based on jane psychiatrists description . I think he didn't kill Teresa Lisbon because he is in love with her. The psychiatrists said that the person is a good whistler when Ray left Lisbon room he was whistling she also said he was narcissistic and Ray seem cocky when talking to Lisbon. I think the whole scared of height is a red herring i don't the person fear of height maybe fear of high objects or fear of flying hmmm. 

I've rewatched the episode 3 times now, ignoring the obvious clues/red herrings (fear of birds, middle aged, good posture, able to creep silently), and that one moment on top of the church, just before he extends his arm to PJ says a lot to me. In a body language sense, i read that he feels totally in control, almost as if he's sending a message to PJ, saying "I don't have to rescue you, i can kill you at any moment, but why spoil our game?"

.

I really dont know if i believe in this.
But as you might know William Blake has made painting called a brace of partridge.
We have also seen a lot of pidgeons in the last episodes. The painting is two dead birds.

painting: http://www.1st-art-gallery.com/William-Blake/A-Brace-Of-Partridge.html

I might be wrong, but its a weird coincidence, if it doesnt have anything to do with Red John.

I know partridge might be dead, and i also think it would be weird if he isn't.