Red John is:

Dean Harken (attention to the anagram for the lover of Red John, Dear Karker - Rosalind)

or Dr. Royston Daniel

or Max Winter

or else, Ray Haffner (In the last episode, when haffner is in the elevator behind him appear the letters R. .... ED)

Heller must give a great twist on the show, or else soon will reveal a big surprise. Otherwise the show will be the biggest disappointment in the history of TV. I love The Mentalist, would be a shame. 

Excuse my English, is not my first language.

I think no one from the List is actually Red John, but Dean Harken(some information there are in my previous post). But I think I wasn't clear enough. Now let me tell you why the list is wrong:
Bret Stiles: Jay Roth was in his 50s, Stiles is 70

Bret Partridge: Dead and Buried. We saw his corpse, so no faking of death. Sorry.

Robert Kirkland: By the looks of Episode 4 Promo, he simply wants to know who Red John is. We know he already has a fake list, plus, he got that list 2 Months AFTER Lorelei was murdered, John had it before she was murdered. Plus, don't forget:
 This is the first debut of Robert Kirkland’s
character in the TV Series. In episode 2x08 “His Red Right Hand”, Kirkland
appears briefly (and un-identifiable) after Virgil Minelli finishes his speech.

After what may have been, an off-screen meeting,
Minelli resigns even though he told Lisbon earlier that day that he would never
give up.

Minelli is replaced by the most capable, Madeleine
Hightower, ex Intelligence Agent in Fresno, CA.



Gale Bertram: He supports Kirkland, he is bald and he is waay too tall, so he can't be. I think Bertram is a multi-functional Red Herring that Heller uses every time he needs.

Reede Smith: Red John has to be really cold-blooded. Smith is the opposite, very brutal, very violent and very stupid. Red John's high self-esteem and idea of nobility(classic music) wouldn't accept to pick a public fight with CBI Agents. Plus, he's in league with Bertram and McAllister. He wants to capture John.

Thomas McAllister: He allied himself with Bertram and Smith, he saved Jane and he's really a secondary character. There is also no phobia of birds, just a natural reaction to a bird flying in his face. Most likely Heller knew that the community would think of Ornithophobia after the first 2 episodes: Admit it: He was expecting you to think of pigeons!

Raymond Haffner: Haffner is not the brightest of the Suspects. Red John wouldn't need Cho to spy on Jane, and also, he would have recognized Jane's writing in the Notebook. On short words, he would not have been fooled on S04E02. Plus, we know Red John's strongest point is his persuasive ability, while Haffner has a very bad relationship with Teresa, doted to the lack of his Persuasive Skills. And it becomes too obvious in The Red Barn, when Lisbon asks Haffner if he was in The Barn at that time. John would have lied to her right in her eyes. However he may be Red John's mole inside the CBI, else, how could John enter the CBI Intranet?

THE RED HERRINGS: Whistling and Lisbon's Dream are more Red Herrings. This kicks out Bertram, Smith, McAllister and Haffner. We see Haffner Whistle and cut Lisbon's throat, a very typical Red Herring from Heller. Same works for Reede Smith, he whistles+he's in the dream. Bertram paints the smiley, and McAllister whistles. Red Herrings my friends.

So, I'm sorry, but I think we have to point someone else. I insist on Harken: Why? Because every point of evidence leads to him. I made a compilation of Evidence that point to Harken:


-        
Dean
Harken is 43 years old, just under 6 feet tall, with short, straight hair, a
soft voice and an odd Scottish accent.


-       
Dean
Harken has a private army/private security, which means he is very influential
in terms of Money. Red John is too. This gives Dean Harken access to many
places via his followers. Note that Patrick made the List of Seven supposing
that Red John has direct access in all those places. He forgets that John needs
only one of those guys from the list either as disciple, either corrupt to gain
“access”. I bet it’s Ray Haffner, Red John’s mole inside the CBI.
-        
Dean
Harken is skilled in informatics. Red John is too since he has access in the
CBI intranet. Again, this may be doted to what I suppose is a partnership with
Ray Haffner.(See my file on Raymond
Haffner)


·        
Dean
Harken has Red Hair. Macbeth(historical) got the name of Red King(Ri Deircc)
because he had red hair.


·        
Dean
Harken is married. So is Red John. Both have rings in their finger. Most likely
to Rosalind Harker. Most likely they are not married officially, and Rosalind
got the name of Harker, not Harken. This way, if Rosalind is married to RJ no
one can track this, because the wedding is not legal and the change of last
name is done by one part only.


 -       
Patrick
can’t stand for Harken, he calls him a person who likes “Scared People”. Harken
too seems a little uncomfortable with Jane and Lisbon around. If he was John,
be may have been worried Patrick would identify him.

·        
Dean
Harken has friends at FBI, at least that’s what he tells Patrick. Friends,
plural, more than one. In the 4th season, 24th episode,
Red John mentioned he had a friend at the FBI. But at the time of Season 2,
John had two friends(Craig O’Laughlin too). Is it possible Dean Harken, a
suspect for being Red John, had more than one friend at the FBI, just like Red
John? For me it’s too much a coincidence.
 -        
Dean
Harken is very cold-blooded in his investigation, Red John must be cold-blooded
in all those homicides.
 -        
He
says that requested CBI’s help himself. Why? Why the CBI? Why not the FBI
where he had many friends. Why, unless he wanted to meet with Patrick, what
other motives could there be behind that?



I KNOW SOME OF YOU THINK IT IS NOT PROBABLE FOR HARKEN, BUT, FROM ALL THE PERSONS OUTSIDE THE LIST HE IS THE ONE THAT CONVINCES ME MOST. THOUGH MASHBURN AND ROYSTON DANIELS WOULD BE GOOD ALTERNATIVES.

Van Pelt look too naive especially in season 5 when Stiles played with her mind like she is a toddler.
But maybe all that is a mask and act she is playing,
I don't have any clues or explanations but i believe that Jane is playing some games for a long time and he don't believe in that list. No matter what Bruno Heller said.

And also those clues that we know about RJ about physical look, age, even gender can all be lies.
Also it is clear by know he is not just some serial killer. He created a cult,like I said before he is on some kind of mission in his own mind.
We don't know his motives and we can only guess.

First of all, I would like to state that there are two theories. The first:
He Is MaCBETH

  The ones who have read the play will know, that RJ and Macbeth have similiarities in their Modus Operandi: Both awake their victims, see their fear and then cut their throat.

  Red John goes by the name of Roy Tagliaferro. Roy, has two roots, the Celtic one which means Red, and the latin one which means King. The historical Macbeth was known as the Red King, because of his red hair. Red hair is something Heller is putting up through the whole show, to every recurring female character(even Lisbon and Hightower, in early episodes have a reddish-black hair glow)

  Dean Harken is 43(age of R.J), the actor Tim Curry is scottish(like Macbeth+Odd accent), he fits description, has informatic skills, is very cold blooded, according to Jane he likes scared people, he is member of the CDCA, a fictional agency, like CBI(counterpart of Jane), and he has Friends(it was plural in S2,i.e. O'Laughlin and ?Mancini on my opinion) at the FBI.

  The Character of Jane is the Shakespearian Counterpart of Macbeth, Hamlet. Note the similiarity between 4x24 "The Crimson Hat" and Shakespeare's play. Hamlet is also featured in 4x20 "Something's Rotten in Redmund", where Jane plays the Ghost.

  The Name, Dean Harken:Dean means Leader of a Cult, while Harken means bowing, obeying, and is spelled same as Harkin, which means Blood-Red color and Pig(at the Elliston farm, the animal shot was a Pig).


  The list is not trust-able. I don't understand how did people
expect for Heller to say "Don't trust the list"... It would spoil the
show. And the Characters: Bret Stiles is a reasonable suspect, but it's
my 2nd theory, Bertram, Haffner and Smith are too stupid all of them
played by Jane, Kirkland too obvious, McAllister is long-forgotten,
while Partridge, I think Heller reads this forum and is using Partridge
to ignite the Fans, plus, Red John is cold blooded in his homicides, almost a purist, Partridge gets very exited by blood and violence.

  Dean Harken is not a psychic, but his wife(or maybe his sister) Rosalind is. In the ancient religions, blind people had psychic powers such as clairvoyance. In this case, Rosalind is a mix of the characters of Lady Macbeth and the Three Sisters, who push Harken into killing, maybe she is the little girl Patrick and Alex frauded years ago and she wants vengeance.

  During the Series, we've had hints of the existence of psychic powers: In the first season, the Witch who bows Cho before the lion(Jane says it's coincidence, but in a later episode he admits that there are no coincidences in the world). Also, Christina Frye is never exposed as fraud, thus leaving only the fact she is a psychic. Same with Sean Barlow. And in a moment, Jane tries to "solve the RJ case in dream", and says to Lisbon Mendelev had seen the Periodic Table in a deam(i.e. psychic vision).

  Most likely, Jane had paranormal visions when he was in deep trance(strange how he never uses self-hypnosis to solve the cases). The paranormal phenomenons taking place while in deep trance are known by the old norse as Seidh. Seidh is a woman's magic, and Jane is, strangely a woman's name. Also Jane is too good to be simply a mentalist, he is a little more than that, maybe because he is very good at what he does, too good for my opinion...

My prime suspect is Dean Harkin

1) First lets look at his name and the meaning. As we know this show there alot of cryptic clues that we have to decipher.

*Dean (Definition of *) - The head of a faculty. The senior member, of any group, organization.
A man who is the senior member of a group
(Red John as alot of followers and clearly he is the Head and Senior member of this group)

**Harkin (Definition of **) - Irish and Gaelic origin, and the meaning of Harkin is "Dark Red".
Irish: Anglicized form of Gaelic Ó hEarcáin
‘descendant of Earcán’, a byname or personal name formed
from a diminutive of earc ‘Red’, ‘Bloody'.


2) In Episode 11 Season1, when Jared Renfrew writes on the wall "He is Mar" - could he have instead meant to have written "He is Har" as in "He is Harkin"  (Just a thought)

3) Rosalind Harker - again a play on names - both Dean and Rosalind have very similiar surnames Harker and Harken.
RJ and Rosalind were lovers and this could be a clue that links them together.

4) He as powerful friends in the FBI - in the episode Code Red he states
"I'll call my friends at the FBI, get them to take over from you. In fact, I will do that."


5) Hes description - He as Red hair and fits the description of what Rosalind describes.

6) He's probably married (has a wedding ring at finger), and Patrick Jane describes him as one who scares people, and an irksome man.

More on Dean Harkin

"I'll call my friends at the FBI, get them to take over from you. In fact, I will do that."
―Dean Harken, on his powerful friends

 Dean Harken is a character in Code Red.
He's an Agent of CDCA (California
Disease Control Agency), based on real CDC (Center of Disease Control
and Prevention), that investigate on biological menace, especially on
dangerous diseases.
He's probably married (has a wedding ring at finger), and Patrick Jane
describe him as one who like scared people, and an irksome man.


He has friends in FBI, possibility of money (stealing the flask of GMO virus), and poison Rebecca with special venom.


In episode Black Cherry, his name is in Jane's List of
Suspects to be Red John, with the notes: Agent CDCA - Red Hair - Biotech
Facility. Jane talks briefly on him with Lisbon.

My theory is Dean Harkin...why....well lets whittle it down

Dean
Definition: a man who is the SENIOR member of a group

Harkin
- The surname Harkins is an anglicised form of the patronymic Irish
surname "O hEarcain", which is derived from the word "earc" meaning
"red". Thus the surname would have originally been born by "a descendent of Red". First name origin & meaning:
Irish: Dark red
First name variations: Harkan, Harken, Harkon, Harkyn
Last name origins & meanings:
Irish:
Anglicized form of Gaelic Ó hEarcáin ‘descendant of Earcán’, a byname
or personal name formed from a diminutive of earc ‘red’, ‘bloody’

He is Har (S1 Ep11)- Harkin!!! Dean Harkin is Red John!!!

CASE CLOSED!!