Alex Jane.

This is my first post and I really don't have a guess who Red John is.  I would, however. like to discuss some things from the series as I have seen it.

I think that the secret on how the memory was detected by Red John has to do with Patrick's stay in the mental hospital.  He has no set memories of what happened during this time ,and I believe that a psychiatrist helped him.   He  seems to have only fond memories of her.   She, however, may have discovered the memory during his treatment and told Red John what the memory was about. 

I really think that Lisbon is the key to this epsiode.  She has an injured arm (from where we don't know)) and was the only witness to the end scene.  I think that she was essential as Patrick already knows from the DVD what the list was going to be.  He gets her to deal out the suspects (not him) ans she seems genuinely surprised.  I think the final scene was an act for her and will serve Jane's discovery of Read John.

Seems as RJ knows things so private about PJ that I am wondering if PJ may have been hypnotized at some point and doesn't realize it. The touching of the past memory that he never shared, the fact that PJ had to learn to be a "mentalist" from someone and how that has been an element along the way in the show would answer how he knew the memory and the seven that PJ had come up with.

Suspect - undetermined at this point of the game.

I believe that we've known who Red John is for quite some time
now. I think that Jane has a very strong theory that he doesn't want to
believe...I say this because whoever Red John is could very well be
someone from Jane's past, Perhaps his Father? Jane's Father encouraged
Jane do trick people while they were apart of the Circus, although Jane
did not feel comfortable doing so with the tricks of physic powers. But,
Jane ends up doing that very thing for a living, fooling and tricking
people for a financial gain, I believe that Jane's Father was upset
about this and saw Jane as a Hypocrite. Jane's Father has sought out to
teach his son a lesson. At first I thought Jane was Red John, how Epic
would that be, huh? Jane himself sets up all these Murders and has
accomplishes that only very few know who he really is. Perhaps Jane is a
psychopath and will ultimately lead the CBI team directly to him and
have them not believing what they see or what all the evidence is
pointing to. BUT, that is just a wild theory that I had in the very
beginning, LOL! I really think it's Jane's Father and the Finale of
Season 5 taking Jane back to his past really makes me think its Jane's
Father, who else would know about Jane's childhood secret and use it to
hurt him?   

This are some of the clues the executive producers of the show (Heller, Gable, Szentgyorgyi, Gable, etc.) have told us about Red John.

- It is very possible that Red John is more than one person. (https://twitter.com/mentalistwriter/status/114527763079245824)

- It would certainly explain a lot if Red John is or was a Mentalist. (http://twitter.com/#!/mentalistwriter/status/114528098116042752)

- Red John has been visible in prior episodes. You’ve got to look for him like Waldo. (http://twitter.com/#!/mentalistwriter/status/114530384280158208) [This comment was made before season 4 premiered).

- Jane is not Red John. (Bruno Heller in an interview)

- "Season 6 apparently they’re going to catch Red John. Seriously, that’s what I heard. I don’t know if I’m allowed to tell you. I don’t know who he is. But apparently we catch him!" (Amanda Righetti in an interview.)

- [Question: Will you cast Red John next season? (this was published before season 5 premiered)] Will I cast him? He might already have been cast. You might already have seen him. (Bruno Heller in an interview.)

- [About the list of 7 suspects] Yes, we can trust that list. As much as much as Red John has been one step ahead, Lorelei Martins’ intervention changed the game. So as much as Red John is trying to play from a position of strength in reality Jane has gotten a lot closer. This last episode of the season really sets us up for next season: The hunt is on, no messing about.

- [About the season 5 finale] This season has been about Jane digging into the notion that it’s not that Red John could be anyone; it’s that Red John is one of a very specific set of people that Jane is uniquely qualified to investigate. The finale is going to pay that off in a way that will completely change the hunt for Red John. We are going to know some very specific things about who he might be. (Szentgyorgyi in an interview.)

- [Question: The arrest or the death of Red John will determine the end of the series?] For me, yes. There will be no follow-up or spin-off. (Bruno Heller in an interview.)

- [Question: Are you spreading clues about Red John's indentity?] Yes. But we're also sneaking in some false clues. Fans will have enough elements to find the solution before the end of the last episode. (Bruno Heller in an interview.)

- [About revealing RJ's identity, before season 5 premiered] Sure, if season 5 we just opened a door and said “tah-dah!” and it was some mid-range actor, that would be disappointing. The trick is going to be — and this is coming — bringing the audience along and making them second guess themselves and ask, “Is that him? Is that him?” Red John ultimately is just a man — whenever you see the great criminals reduced to the flesh it’s sort of disappointing. I have two seasons or so to make it come true. [Joking dryly] I can guarantee that people will be disappointed. (Bruno Heller in an interview.)

That's all I could find so far. If you have any more clues from any of the show producers, please post it in the comments.

David Charles is Red John.

Season 2, episode 3.

Red John is Reede Smith.
He is the least likely suspect on the list and we know how to expect the unexpected on The Mentalist.
Also the play on the names Reede Smith and Red John.
Reede is derived from "Reed" which means "Red"
Smith/John is a generic name sometimes representing "everyman" or "the average person."
Why would a guy who only acted in 1 episode and have a 10-15 min role be on Janes 7 main suspects list unless..