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.