Some points that R "clear" to me:

Partridge IS dead...
Bruno Heller might be lying to us (he has done it before...) but it's hard to say where that lie could be...
Rosalind H description of RJ is LAUGHABLE... She's blind and she's lied before too...
The list of 7 is a trick from Patrick...
Sheriff McAllister did not appear in pilot episode BUT in 2nd and that "little detail" is waaaaaaaaaaaaay important in my humble opinion...
He fits the man who poisoned Rebecca's description IMO and, "as a Sheriff" seems very capable of several facts that could lead us to think he might be the one...
All persons included in the list of 7 are close to RJ...

Sheriff McAllister will be Red John...

red john/roy tagliaferro spent few months in relationship with rosalind h. and nearby with someone(cant remember his name, but i think he got killed later, they kidnapped twins) so in my opinion that man couldn't be bertram or anyone in cbi because everyone would notice someone's absence for such a long time....?

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I noticed one very interesting thing from the list of 7.I dont know if its really important but its worth to mention it.From the 7 suspects of the list there is only one of them whom his appearance on the show isnt connected at all to the Red John case.And this man is Sherrif Thomas McCallister.In his appearance in s01e02 we have zero mention to Red John and it seems one episode with another killing that PJ and the team will solve in a smart way.Think of it.
1)Brett Partridge:All his appearances except one were in episodes referring to Red John.
2)Bret Stiles:Helps PJ to get Lorelei out of prison and also in another episode talks to PJ about RJ and how RJ takes all the things from PJ's life.
3)Gale Bertram:He is also connected to the Red John case in s03e24 where we thought at the beggining that he was RJ's accomplice before we find out that O'Laughlin is RJ's accomplice.
4)Reede Smith:His only appearance is in s05e01 where he and Mancini at the beggining have an argument with Lisbon and her team about the Red John case.Also take a look at his face when Rigsby says "We were this close on catching Red John...etc".
5)Bob Kirkland:Well what can i say about BK.He killed Jason Lennon.He is the chief in finding Lorellei when she escaped from prison,he break into the room of PJ.All his appearances are connected to the Red John case.
6)Raymond Haffner:S04e01.He and his team replace Lisbon's team cause of their suspection in killing Timothy Carter(fake RJ).And of course s05e13.The episode that we learn that RJ started to kill in the late 80's and was a member os Visualise as Haffner too.

Something interesting I noticed about the suspect list is all the photos Jane had (the one's Teresa laid out as Lorelei read the list) are current except McAllister's.  Take another look at the opening scene to Season 6, Episode 1.  The picture of McAllister is from his younger years.  I'm wondering why that is.  I'm not saying Red John is McAllister, I'm just wondering why Heller chose to show a younger picture of him rather than a more current one like he did with the other six suspects.  

A weak thought but possible is that I remember that lorilli martens said that red John rapped her sister. Sherriff Thomas McAllister looks to me like he could be a rappist. Also he liked van pelt.

There is absolutely no evidence to support this theory that Sheriff McAllister is RJ, just going on the fact that Xander Berkeley is not the sort of actor you bring in for 1 episode, in such a small role, and then never see again. That's how thin this theory is.

He doesn't fit the physical description, he wouldn't be able to gain access to the CBI, he doesn't look like the Visualize type, and he's probably too old. But again, why cast a good actor in such a small role, and why is he on Jane's list? 

My theory is that RJ is older than people suspect him to be. Haffner (if my maths is correct) is 46 years old, Bertram would appear to be about the same age, Partridge is dead, Kirkland looks in his late 30's, Smith looks too young, and Stiles is too old. 

Which leaves McAllister, who is based in Napa county (which O'Laughlin mentioned before), roughly mid 50's (right age for a serial killer, would have been about 40 when he started). 

In RJ's friends, the writing "he is mar" is seen on the wall. As the hooker was mexican, maybe she misspelled McAllister "Marcallister" ( i did say this was thin).

And finally, maybe he changed his appearance to fool everyone? Xander Berkeley cleans up pretty well for a man his age, maybe McAllister is the same.