I cannot say who Red John is at this point, but I don't think Brett Stiles is Red John.  The reason is that the rivalry between BS and PJ is too obvious, not to mention how SIMILAR they are.  Both men have a "cult" like following, are highly charismatic and know how to work people -- of course, they'd be uneasy toward one another, they cannot influence each other!!  For now, it is a sore spot, but someday, I predict it will turn into something almost resembling mutual respect, and they will possibly work together to get Red John. 

ONE thing I know for CERTAIN:  neither PJ or BS are RJ -- because RJ is a power hungry sociopath incapable of caring about others.  Both BS and PJ deep care for others, no matter how much they play it off.

RJ probably has an ordinary, mundane life,"invisible" because of a seeming respectable or meek quality, or he is in an enviable position as a sort of prodigal son, in a family of wealth, power and influence where he is always in the shadow of a more power person within his family.  No doubt, RJ feels "robbed" and wants to achieve the glory that both Stiles and Jane enjoy daily and experience effortlessly, but that EJ secretly fears he's incapable of [which is true!].  RJ wants to be like PJ and BS, and deeply admires both.  He's someone who has likely positioned himself very closely to both men.  LOVE THIS SHOW!!

Hello Guys.

Please, stop the nonsens theory that Patrick Jane is Red John!! This is absolutely bullshit and if I well remember Bruno Heller said before Jane isn't Red John!!

My opinion is the simplest answer is the most probably (Occam's razor) so looks like Brett Partridge is Red John. Of course, only Bruno Heller knows who Red John is. I hope cooming soon he will be revealed.

Not really a theory on RJ but I am really looking forward to episode 18:  Behind the Red Curtain.  It involves a murder that interrupts a musical preparing for Broadway.  I would just love it if Jane made some disparaging comment about musicals and Lisbon declared her love for Phantom of the Opera to which Jane could reply that the Phantom is a singing serial killer then Lisbon could zing him with his similarities to Sweeney Todd.  I just watched that today and the similarities are interesting.  Both Jane and Sweeney lost a wife and daughter.  Both are on a quest for revenge that gets people killed around them (Bosco, Panzer, Jared, etc might have all lived if Jane hadn't been actively pursueing RJ).  There may be more similarities depending on how Jane's story ends - will he learn like Sweeney that it would of been better to "learn forgivingness and try to forget."  I really can't see Jane catching RJ without one of the team getting killed to give weight to the victory.  Hopefully that's why Lorelei was brought in so that the team doesn't need to lose someone but frankly I don't see Lorelei living past episode 16 in this season and definitely not past the S5 final.  Someone important is going to have to die at the very end of the show and it better not be Lisbon.

And for a single RJ thought:  I believe Mashburn is RJ and I scan the summaries of the episodes to look for clues as to which one he might be in this season - it better be one of them . . .  Well, like IKWRJI said, Mashburn is part of the nouveau riche and could easily be patron of the arts.  Maybe he's sponsoring the show.  Too bad the cast list isn't out yet.