I believe Bret Stiles is Red John. (If this is the wrong person i am talking about and his name is different, excuse me for that :P)

Firstly, Bret knew where Kristina Frye was kept after she got stolen under security of the Team.
He gave exact directions to the house she was in (Why did he do that? I do not know) and when Patrick Jane got there she was in a room with no furniture and only a chair and she was sitting in it. Her face blank. she only gave contact to Patrick Jane when he "summoned" her from the dead and talked to her in a dark room with a candle. But easily that could be hypnotism and Bret can easily do that. He could have hypnotised her and made her believe she is dead and can only talk to the people who summon her from the dead and forget who killed her.

Lastly, Bret has a lot of power which he can use. In Season 5 Episode 8, In the beginning, Jane goes in the movie theatre and watches an old movie with him. They used that as a secret meeting place. And Jane asked Bret to get Loralie out of jail for him and he neglectively agrees. ( Neglect a sign of "i don't wanna do this !"?) He does it easily. And Loralie was in a very high security prison. Bret's nickname could be Roy. (Im not sure about this next part) Bret might dislike Jane very much but not show it... also a sign of (Season 5 Episode 8) I can't believe you weren't good friends the moment you shook hands with Red John. (Loralie says that.) 

P.S Bret Stiles (not sure his real name) plays the bad guy ALWAYS in movies. 

P.P.S for the "I disagree" people who read this:
He might not be Red John. He looks very kind and doesn't look very serial killer-ish but then again he could get other people to do his dirty work for him, He might not be Red John but there IS some sort of connection between Him and Red John. 

I think its Bret Stiles. He is The one that would enjoy Jane Boeing tortured as well as leasing him in The dark, pulling strings for The search. He is a psycic like Jane and he us The one that can read him better than anyone else. Kristina Frye was also an psycic and she us friend with Red John hence Bret Stiles.
Bret also likes to control people and that is also what Red John likes...controlling people to do what he wants them to Do like puppets or marionettes.

I think Red John is Brett Stiles because:
-He is powerful because he is the leader of visualize
-The cult is brainwashed and afraid of him so he can get people to do what he wants.
-We know Red John drinks tea{1x23 & 4x13} and also Bret Stiles does{3x03}
-Bret Stiles shows interest in Jane and Red John
-He gave the location of Kristinna which led to nothing
-He is smart enought to be Red John as we have seen many times
-After Jane talks to Bret Stiles in 3x03 staright away we meet O'Lauglin who was a proven accomplice of Red John.I think that Bret Stiles sent O'Lauglin to spy on the investigation
-Bret Stiles has already killed and got away with it.
-In 3x03 we see Bret Stiles arrive in a limo which is Red Johns favourite choice of car
-Jane has even called him Red John

Red John (not me.... or is it?) is Brett Stiles and i know this because Brett is the only person that knows secret information about Patrick Jane which noone else knows, this implies that Brett Stiles has studied Jane or been in his house and the only time that Brett could be in Janes house would be to kill his wife and child. Brett Stiles is also a very powerful man meaning that he has the money so that he can cover his tracks by framing other people.

just my opinion

My Main solution is that episode when RJ killed his "accomplis'es" friend in Mexico he wrote on the wall "he is,m....." there was another letter after that but I could not make it out

I am about 75% sure he could be red john . If not then probably someone inside the CBI who's under the radar