Not saying he's RJ because i seriously doubt he is, but couldn't he be Red Johns contact in the FBI that is mentioned in the series 4 finale ? 

Thats why i think he's on the list. 

We
can't technically rule any of the 7 out, that's how they've done it on purpose.
If Jane doesn't know, we can't know. But it's about what fits best.



Haffner started out in FBI and was known for creative surveillence. This allows
him to make friends in the FBI and later CBI. It also allows him to keep a
secret eye on Jane, which would explain how he could work out Jane's list
without him knowing, and means there's no need for it to be Kirkland (who broke
in after Lorelei read Red John's message with the list). It also means he's
bound to be good with techonology, which fits all the hacking into CBI
networks, and perhaps mental hospital records (the only logical place where
Jane's memory of Eileen Barlow could have come out).



As Haffner, he's actual incredibly likeable, which would fit with gathering
followers. He's in the show little enough, but also just enough, that he'd
appear a red herring.



His two episodes are important though. S4E02 is when everyone except Jane
thinks Red John is dead, and presumably Red John thinks Jane thinks it too. So
what better way to stay close to, and maybe mess with, Jane than to become his
new boss, since he can't do it as Red John anymore? It would also fit if the
original plan was for Timothy Carter in the mall to actually be Red John, but
they had to switch once they got renewed for another season.



S5E13 sticks him alongside a Red John investigation, which he keeps a close but
secretive eye on, accidentally giving away his spying by asking about evidence
which he wasn't supposed to know about. At the same time, he tries to take
Lisbon away from CBI (a few weeks before Lisbon's wrist is mysteriously broken,
shortly after which Lisbon reacts differently to Haffner's name on the list compared
with the other names, perhaps a "Oh wow, Jane actually suspects Red
John!"). When Lisbon asks him whether he was at the barn, he dodges it in
a creepy, suspicious way (as if to say "I know you know I was there, but
you can't do anything about it"). Along with his Visualize membership,
this suddenly moves him from completely insignificant to blindingly obvious, so
much so that we just assume he's a red herring to throw us off.



The Visualize connection would explain Stiles' knowledge of Red John, how he
could have the money has, as well as another way for him to gather committed
followers, as many of them could be Visualize members too. It also fits with
the apparent connection between 'Tyger Tyger' and Visualize ("What
immortal hand or eye..." and the picture of a hand and eye on the
Visualize building).



As an extra pience of subjective evidence, the Red John smiley fits with a
Visualize connection (although since Red John was connected to Visualize in
1988, this could work for any of the 7). The Visualize eye is like saying
"I'm watching you", and the face could be too, which would fit both
Partridge, who is at most Red John crime scenes when CBI (and Jane) are. It
also fits with Haffner if he used creative surveillence to watch his murder
sights being investigated. Alternatively, the face appears a variation on the
eye: where the eye says "I'm watching you", the face looks to be
saying "Haha, look what I did!" in a smug way, which would be a
taunt, inspired by the Visualize eye. But again, very subjective.



Haffner also fits all the physical clues we have of Red John, such as his
height, his build, his hair, his being "not hard but not soft" (even
though Harker's testimony isn't necessarily reliable). Haffner is bland and
forgettable, but also likeable yet slightly creepy (his face just screams 'Red
John!' at me, but that is completely subjective), which would fit with nobody
batting an eyelid when he's been around CBI (poisoning Rebecca, walking in and
out with a cap on, riding a bicycle around.



We believe Red John to be married and have a wedding ring, and although I don't
remember seeing a ring on Haffner's finger, there could well be, and he seems
like the type to be married.



On top of all of this, Bruno Heller has said we would be disappointed by who
Red John is. Partridge, Bertram and Kirkland are too obvious to be
disappointing, Stiles is too awesome (and maybe too obvious) to be
disappointing, and Smith and McAllister have nothing to make them more likely
than any others (plus Smith is too fat). Since any of them COULD be Red John,
this isn't really evidence, but could be taken into account if you like. He
does, in a sense, hide in plain sight. Plus he shakes hands with Jane on
screen.

Icing on the cake of awesomeness that is this theory: 'Roy' and 'Ray' are a little bit similar.



The combination of actual plot presence, as well as the formula of writing such
a mystery, and the hints we've been given by writers, makes Haffner a perfect
fit. It's not hard, infallible evidence, and Red John could be any of the 7,
but Haffner makes most sense to me.

Let's first admit that there's not enough information too be sure of our choice.
My suspect is Ray Haffmer, he's the only one left after a process of deduction.

I started with the description of Rosalind. I do not count height because they are all very close together and I don't think a blind woman (or anyone without a measuring tape) can be precise to the inch.
Rosalind's description removed Bertram, McAllister and Stiles from my list.
Bertram is obviously bold, and too heavy to be RJ. Even if Rosalind's information is incorrect, he doesn't match the body type of RJ. (We must not forget that we have seen him when he rescued Jane from his copycats)
McAllister is too old to be RJ, his skin texture differs too much to go unnoticed by Rosalind. He is also too creepy and awkward for RJ. RJ is charismatic, intelligent and a charmer, otherwise he would never have managed to create such a loyal groups of followers. He might try to hide these things to protect himself, but his narcissistic nature won't allow him to play a fool.
Stiles is also too old and probably doesn't have strong hands. Stiles is into manipulation and is at the top of an cult. He doesn't do physical chores, so his hands are probably very soft. He does enjoy to play games with people, and thus enjoys to play mind games with an intelligent man like Jane. This is very like RJ, but Stiles methods are different. RJ likes to play games and teach his component that he (RJ) is always smarter, always one step ahead. Stiles games are puzzles that Jane can solve, and Jane (almost) always profits from the outcome of the riddles. Stiles is however involved in everything, I think he is pretty conflicted. On one hand he wants to help Jane, but on the other hand he protects RJ.

What really bothers me is the popular thought that Partridge is RJ. I can't understand that one.
It is shown that RJ gets very angry when his work is copied. He can't help himself once that happens, he has to harm or kill that person. Otherwise he would never have killed Panzer 'for' Jane, since RJ likes to be in charge. The first time (I think it was) we meet Partridge is when he shows Jane and the team around on a fake RJ case. He is in his element, very theatrical. This seems like RJ, because RJ likes dramatics (playing with emotions with his smiley face). But RJ wouldn't be able to be this way when he is talking about a (very bad) copy cat job.
An other point is his behaviour in general, he seems a bit foolish and Jane talks down to him without any payback. Remember that that is exactly what caused the death of Jane's wife and daughter. RJ hates it when people make him feel small or stupid and goes to great lengths to prove he is the smartest man alive.
His body type matches pretty good, he doesn't look bulky or very soft. He probably isn't strong enough to take people down hence the taser.
But I don't think the taser is a sign of a weak body. It is very effective and clean, and that's why RJ uses it. RJ works very precise, sees his kills as a work of art. With a taser he can avoid a struggle and minimize the risk of leaving evidence.

I had to look up Reede Smith, because I didn't know who he was. Purely looking at his character, there isn't much to say. Only that he is too broad to fit the body type (at least, it seems so in the picture). Of course his name is perfect, but it is too obvious.
When you look at the build up, it would be weird that RJ gets introduced in the 5th season and only gets one episode. I cancel him from my list based on this fact, it's very feeble and I am aware of that. It is mentioned that we would be dissapointed to see who RJ is and that would certainly be the case with Smith. But I don't think that is enough to make him RJ.

Then it's down to my two 'favorites'. 
Kirkland seems to fit the part, with him killing the guy in the hospital and stealing from Jane. That however, is exactly why I decided it isn't him. I have to admit, it is only because of the way the series is filmed, so I won't be surprised if I am wrong about this.
Kirkland lacks the subtle, almost elegant vibe that RJ has. He is very 'solid', while RJ is as solid as thin air. RJ is able to go everywhere without getting noticed, there is always that sense of mystery.
He is however cold as ice and a good lair. He would be an excellent accomplish of RJ.

Then we have Haffner lets start with his career.
He worked at the FBI as an expert in wiretaps and creative surveillance techniques. Wouldn't that be handy for connections and skills. It would certainly explain how RJ is always a step ahead (because even a good spy wouldn't be able to get into Jane's room to view the suspects).
Then he came to the CBI, he shook hands with Jane and it is clear that Jane doesn't like Haffner.
Haffner is a member of Visualize and has learned to profit from is charismatic and charming manners. He also has the right age to be at the farm.
When Jane was on his team, he tried to control him by being smarter, which failed. RJ is very intelligent, but is used to the advantage that he knows and sees his component while Jane is fighting an invisible force. So it is very plausible that RJ can't compete with Jane when he is out in the open and isn't surrounded by people who are his puppets. RJ needs his followers to cover up mistakes (to kill witnesses etc).
A few fun things about Haffner, his name Ray comes incredibly close to Roy (the name Rosalind uses for RJ) and it is kind of a mindf*ck that Haffner and Jane were in the same team for a short time.
There are a lot of things that I have forgotten to write down, but my fingers and brain hurts from typing this. I apologize for mistakes, English isn't my first language.

I'm struggling to see how Jane could be Red John ?

In the episode Red Johns friends, Jane is at the CBI with the team while Red john kills someone. 

Need more evidence ?

In the season 2 finale Jane is tied to a chair by 3 people who are going to kill him when Red John appears and shoots all 3 people and then knifes them to death. He then picks Jane's chair up and sings a poem at him, we see them face to face !

He can't shake himself by the hand.

And lastly in the Season 4 finale Jane gets into a car and talks to red john down a phone. Red john responds and hangs the phone up.