Red John is of the seven - now just 6  - suspects.

SO! RJ inst:

-Jane himself, Lisbon , Van Pelt, Ron. ect...
- Brett Partridge already dead, Bruno Hller confirmed, Jack Plotnick confirmed

We get closer to the RJ mystery step by step, episode by episode until episode 6x08 called Red John. The 6x09 title is My Blue Heaven.

My top suspect is Kirkland:

- He hates Jane it seems at the closing scene in 5x18
- He knows Jane spent a half-year in an insane asylum, and probably knows his psychiatrist named Sophie Miller
- Red John's got a friend in the FBI, Kirkland have closed prelationship with FBI Director Alexa Shultz
- He met CBI Director Vrigil Minelli az 2x08
- His limo appears in 2x08, and 5x05 and this very similar to what we see at 4x24, when Lorelei cathes Jane.
- That way he kills Jason Lennon, similar to the way when RJ kills Rebecca in 2x08.
- He calls Jane first time Mr. Jane, after just Patrick, likes RJ

I've read a lot of theories, and I was one of the ones who tought it was Brett Partridge...
People still thinks it's him but I don't think it's Partridge.
In the episode 1 season 6 the real Red John was hiding in the bathroom.Nobody noticed that the bathroom's door was closed and when Lisbon turns it was opened?
That's why she looks scared and suspicious when stares at it...it also seems she is grabbed from behind and she is giving his back at the window, she mantains the same position since when she get up, this means Partidge body is in front of her...how could him get up and grab her from behind withouth being noticed?
Sure, it's television and everything is possible but now I think that the theory that RJ is Partridge is poor..

Sorry for my english.

Another stupid theory i've already heard:

Red John is not on the list. RedJohn is Dennis Victor (Ray Wise) who was appeared on episode 4x23 "Red Rover, Red Rover"

And just for the following reason: "To make a wink to the TV Show "Twin Peaks" (1990) where he was the famous killer who killed Laura Palmer. 23 years later, Ray Wise is the killer, again."

Whoever Red John is, my theory is that he is someone from Patrick Jane's past in the circus. They may have met before (and Lorelei's words about shaking hands may refer to some distant past), but for some reason Patrick doesn't recognize him (RJ was a child/a teenager or perhaps in disguise?). That would explain how he knows about Patrick's happy memory. Bruno Heller says in his latest interview that this question is going to be answered in the next episode - I'm really looking forward to it.

  Latest comment of mr Bruno Heller about a "very big clue" in last sequence of episode "The Desert Rose" had only strenghten the idea that Red John is the devil himself (pentagrams, 666's, marks of the beast etc. on walls when Lisbon enters the abandoned house and many other signs in previous episodes). He uses his minions to fulfill his deeds. Brett Partridge is nothing but another tool in this episode, like every person on the list that Patrick had made. The list of suspects is a second great plan (another one after his "year of despair") to roundup the real killer. Jane knows that he can't keep a secret unnoticed and just let it spread, Red John might take action and might make a mistake.

In my humble opinion the character known as Walter Mashburn is a human personification of devil, Red John, the only bed lover of Theresa Lisbon.

Just an observation really and something that i haven't seen brought up, when lisbon enters the house (whos house is it??) there are signs on the wall in red (possibly blood) that say "DIE" "666" and a pentagram?? 
Now they may not be significant and i can't really think of any theories for the symbols other than its religious? and the poem tyger has been analysed as a religious poem. 
Sounds weak i know... just wondered if anyone had any thoughts??

First of all: I have an idea who RJ really is, but I'm not shure.

Partridge is dead. It is confirmed by Bruno Heller and Jack Plotnick. Jack Plotnick also stated, that his voice was nerver used for RJ. Bruno Heller also stated, that Partridges death was a part of RJ's plan. Partridge HAD TO DIE that early. In addition to that he stated, that there was a major clue in the final scene of 06x01.

According to this, I think I figured out the "major clue".

Fact: Partridge is dead. But AFTER he died, RJ called Patrick and spoke to him with a voice very similar to Partridges voice. He did the same a couple of times before and he also spoke with a voice similar to Patricks (Lorelei in the limo). Some of you thought, RJ used a voice maipulator. But I think, you're wrong.

Fact: RJ painted Lisbons face in a "clown stile". Remember: There must be a link to Patricks carnie days.

Now adding this: Here is the "major clue".
In fact Red John  is a quick-change artist and an impressionist.

And that's how he could "act like Waldo" for so many years. No, no, no! He is not imitating Elvis or Tina Turner, maybe in his own carnie days. :-)

In this way, he collected the informations to make the list. We all know, that Lisbon is a "chatterbox". She was the only one, Patrick told about his plan to make list. She may have told that to...no, not RJ, intentionally...but  RJ, disguised as (maybe) CBI- Ron?

Do you think, this is nuts? Well have you ever heard about a french 60s crime-comedy movie called "Fantomas" featuring Jean Marais and Louis de Funes?