Does anyone remember the episode where they show RJ holding a cup of tea with his left hand? If you zoom in on his hand you can clearly see what looks like a wedding ring.

Only two of the suspects wear a wedding ring: Gale and Tom.
Though Bertram doesn't strike me as a killer type persona, I'm still suspicious about him.

Guys, you guys are so stupid, or are on laxatives. Obviously it's one of the 5 left. If it so happens to be Brett Partridge, send me to the morgue: Everybody, everyone who found him dead, all the the doctors and morgue attendants must be his minions. All the CBI. Jane must be stupid too; I don't think he could be played that easily.

People saying it's Walter Mashburn: Come on, he was gone so far back! Just face it: He's not on the list! All those who are saying: Heller said Patrick would face Red John in the end of the 3rd season, but it was a fake, so Bruno is screwing us again.... Dumb! For one, CBS wouldn't approve. Second, he said it's one of the 5 remaining. In Lisbon's latest interview, she says... I was very surprised, I wasn't expecting to be that one on the list...

I have narrowed the list down to two suspects: Gale Bertram (Michael Gaston) and Reede Smith (Drew Powell) . I got those two by: WIKI ing all of the suspects. All of them (but two) 's final episode is either Fire and Brimstone (Bret Stiles and Sheriff McAllister and Ray Haffner). Only Reede Smith and Gale Bertram's last episode is Red John.

One of the two is RJ. Now let's make a list about the two.

Reede Smith could be a good RJ. He definitely has the tools (in more ways than one) and connections. It would make sense: that's how RJ knows about so much going on in the FBI. He has the personality: not afraid to kill, example Bob Kirkland. He is very antagonistic, and there is definitely much we don't know about him. But in the records of Janes old psychiatrist, she says that RJ is in good health. Reede Smith is so fat, I'm not sure that would be in good health. The writers had this in mind while they were writing the script. They wrote it after they revealed the final suspects. He hair would be like they said though: short and straight. According the Rosalind Harker, RJ is under 6 feet tall (in think so with Reede Smith) has a gentle voice (not sure about that) and not muscular but not soft, either. Smith isn't muscular, but definitely to soft.

Another thing: Ray Haffner is very muscular. Remember in the second episode of Season 6? It shows Haffner doing intense pull-ups. He is muscular, yet another way to rule him out. Bret Stiles is, I think, way to old to be killing and raping 31 women (so far). Sheriff McAllister seems like a likely candidate: seems like a perv to me, but also to old.

Gale Bertram is middle-aged, has short, straight hair, has the connections (it would explain his knowing what the CBI is up to, he is very high up on the rank, and even quoted a poem from William Blake in the episode Red Queen. Don't forget: William Blake wrote the infamous Tyger Tyger poem. I think I have also heard him whistling at times: again, Jane's psychiatrist said her patient was a very good whistler. He is probably a member of the Tyger Tyger conspiracy. Something from the WiKi:
Bertram R. Forer was a scientist that experimented The Barnum Effect for the first time (also known as Forer Effect), which is related to cold reading (the ability to gain information about someone without that person realizing that they are actually giving the information themselves) which is what Jane often does and a skill that Red John must be very good at. It might be a coincidence, but it can also be something that Bruno Heller wants the viewers to think about. In a previous interview Heller stated that Red John likes the cold, a statement that has been often interpreted for cold weather, but there is a possibility that cold in the sentence is related to cold reading instead.

But then again, also in the second episode of this season, it shows Sheriff McAllister whistling in his police car.

ANYWAYS, IT IS ONE OF THE TWO. I HAPPEN TO THINK IT IS.........

one of those two. I'm not sure.

the main reason that made red john kill jane's family is because jane insulted and disrespected red john in public, we understand of this that red john is proud, sadistic and enumerate any evil characteristics. it is like a message for jane "Don't you ever show irreverence to someone you don't know".
apparently, in S1E1 jane described brett as "ghoul" which the red gohn is but the interesting thing watching partridge's face expressions, like he says don't mess with me he hated that jane humiliating him every time.

just a thought ^-^

(Scoop from TVLINE)
I was told to email here if I wanted scoop on The Mentalist, so here I am. –Olivia

Indeed, you are. “Armed” (heh) with the new tattoo clue, Jane
sets out this Sunday to round up all five remaining suspects, only to
find that one of them has gone missing. Long story short, the
aforementioned ink leads to a rather surprising reveal, and that shotgun
Jane is waving around in the promo does go off.
Do you know who made Van Pelt’s wedding dress on The Mentalist? It is very pretty. –Mitch

Vera Wang. And yes, it was.

I think the "plausible" button should be the red one.

PATRICK JANE IS RED JOHN

I think that RJ is Oscar Cordero, the guy who brought papers on Bob Kirkland murder to Rigsby. I know that he isn't a major character in the whole series, moreover I think this is the first time he showed up (let someone correct me if I'm wrong).
 From the beginning of the season 6 I never bought the story with 7 suspects. I know that there are a lot you guys who believe that Red John has to be on the Jane's list (list he told to his CBI partners) because Bruno Heller officially confirmed it. That's OK, but honestly if that's true, I think the series will turn out as one of the biggest flops in recent years. Why would you simply tell your audience after 5 seasons who the "real" RJ suspects are when you haven't told them almost anything in last few years. A wise man, good director is never going to do that, now I only hope Bruno Heller is a wise man.
Why do I think Red John is Oscar Cordero? I don't know. I got a weird feeling when he showed up. He is so neutral. He matches RJ's description, short hair, average height, kinda normal voice, not muscular but he doesn't seem physically week. Actually, when the idea of Red John being him crossed my mind was when he said to Rigsby that maybe one day he will do favour for him. That's what RJ wants, other people to follow him, to obey him, to do favours from him. By the way, on IMDB it says that he features in "The Great Red Dragon" and "Red John" so he's not a character of zero significance. The only thing that doesn't match is his age, he looks like he's barely 30.
I don't know guys. That's just my guess I wanted to share with you. Most probably I'm wrong, but I wanted to contribute to this site before it shuts down, before saga is over.  

The original Patrick Jane is Red John.
The Jane that we see now is in reality Jane's wife. She didn't die.

Next episode Jane's wife will try to perform inception on the 5 suspects while Lisbon drives the car.