I believe the clue Heller was going for was this at the end when rj was painting the face on lisbon it symbolized working at the circus were pj worked at rj has never painted the face on anyone also the knife part with the blood when clowns or performers put on make up they use two fingers so my theory is it is someone who worked at the carnival remember what Heller said he's like waldo what better way to know someone then to work close to them also the voice rj uses is some what like a clown or performer I believer rj performs parlor tricks. To me out of everyone mcallister has the clownish or performer look. In my eyes stiles and haffner do not need to kill they are allready master mind controllers. It is someone who knows Jane very well and are either mentalist or someone who is just like jane. Also I am not going off rosalind description remember red john wants you to find what he wants you to find I believe she is in on it as well remember red john has women working for him rosa= red Kristina red hair why Kristina remember the episode were she tells Jane your wife said your daughter was asleep etc no one and I mean no one has made Jane cry put rj and Kristina has. I would not be surprised if van pelt Kristina Lisbon and Rosalind have been playing Jane the whole time now that would be a double edged sword.

In the promo for 6x02 episode, you can see Sophie Miller's (Patrick's psychiatrist) face in the picture on the fridge. Above that picture is note from Red John. So, Red John probably found out Patrick's happy memory from Sophie Miller.

As for who RJ is, Partridge was my favourite, but since he is 99,99% dead, I will say McAllister only because we know very little about him.

If Brett Partridge is dead and he isnt RJ and i say IF because this photo here from s02e08 http://thementalist.wikia.com/wiki/Forum:Red_John_Theories?file=Vlcsnap-2012-10-09-23h24m43s165.png tells me that Partridge is either Red John or a very faithful servant of RJ who accepts to beat till death by real RJ just to misslead Lisbon for RJ to catch her ,then there is only one option.Sherrif Thomas McCallister.First of all he and Partridge are the only ones from the list of 7 who appeared in season 1. Second Dumar(s01e23) was a sherrif more than 10 years as he says.He is too young dont you think?So someone else who is also a Sherrif put him in that place.In s01e02 where McCallister appears we have the same thing with S03e24 where the fake RJ revealed.And of course RJ isnt gonna be Gale Bertram as many of you suggest..Come on you saw that dialogue between him, PJ and Lisbon...Way too obvious!!!!I really cant wait for the next episodes !!!

Remember the episode where kirkland and bertram were working together? They appear to be hidding something, well ... I think kirkland told bertram that jane is getting closer to red john because he entered janes office remember? Its not because bertram is red john ... Too obvious and way to far fron the rosalind harker description ....

Haffner was easily fooled by jane in the first episode he appeared, reede smith is simply doesnt appear to be redj ohn,no arguments ....

Brett partridge didnt say tiger tiger!! I hear .. Mc ... Mc .. Thom mc a ... Something like that ... Also ... He is mar ... Mcallister! He will be appearing in episodes 2 and 3 .... Inteoducing him more as a suspect.

"There is a clue buried in that final sequence that will pay off big time in the finale of the Red John story. A very big clue. No one will get it from the clue as it is laid out in the episode, but it will pay off later." - Bruno Heller

My guess: Is that Red John is left handed, something that's been suggested in previous episodes; after he ran out of the house Dumar and Jane were in, his tea cup handle was shown pointing to the left. Later, Rosalind Harker calls Jane and Roy is shown holding a tea cup with his hand.

I've checked for left handed characters in all previous episode.

There were a few possible ones, but I'll stick to the remaining suspects: 

Stiles, Haffner, Kirkland, Bertram are all right handed.

With Smith and McAllister and it's not certain, and both of them are displayed as "in transit" on the cell tracking monitor.
 

Lets look @ the 7 suspects and how many times they have been seen (Bret Stiles 4 Episodes) (Gale Bertram 12 Episodes) been seen to many times so he’s not rj (Ray Haffner 2 episodes ) maybe (Reede Smith 1 Episode) (Bob Kirkland 6 Episodes) way to obvious (Sheriff MCallister 1 Episode) Brett Partridge 4 Episodes) My bet is mcallister think about it he is been  seen less (M)c(A) lliste(R) = He is mar plus red john is older than jane comment if you agree

Lets look @ the 7 suspects and how many times they have been seen (Bret Stiles 4 Episodes) (Gale Bertram 12 Episodes) been seen to many times so he's not rj (Ray Haffner 2 episodes ) maybe (Reede Smith 1 Episode) (Bob Kirkland 6 Episodes) way to obvious (Sheriff MCallister 1 Episode) Brett Partridge 4 Episodes) My bet is mcallister think about it he is (M)c(A)lliste(R) = He is mar plus red john is older than jane comment if you agree