Ok, First of all. Let us assume that all what Bruno Heller said was true. He said that one of the 7 suspects is infact Red John. Let us do an elimination process by connecting the things Heller said.

Brett Partridge - Heller said he is dead so let us cross him out of the list

Bob Kirkland - On 2011, Heller said that Red John is someone we know and Kirkland appeared on 2012 so let us cross him out as well.

Reede Smith - We all know that he cannot be Red John since he is too fat to fit the Red John we saw who kidnapped PJ.

Bret Stiles - Sophie Miller said on the recorder that he is on his mid-thirties and Stiles obviously is not.

*That leaves us with 3 Suspects: Bertram, Haffner and Sheriff Tom McAllister.

Most of you thinks it is Haffner which is possible because of the whistle he did after talking to Lisbon. And he calls her Teresa just like Red John does. And when Sophie Miller said on the recorder that he is a great whistler, they showed Thomas Mcallister so you all assume that it is Haffner since they didnt show him.

But they obviously meant to do that so that we will think it is Haffner. I mean we all know how the Mentalist writers think, and it is usually difficult to predict who is the murderer in each episode.So I dont think they will make it that obvious.

That leaves us with Bertram and McAllister. 
Personally, I think that Bertram is innocent just in my opinion. So I'm going with Thomas McAllister. But its still possible it is Bertram or Haffner since there is no valid point that they cant be Red John.

I continue with my theory Sheriff Rj   Dr. said that whistling good, well Haffner whistle, but not very well... at the end is the that whistling Sheriff gives to think many things but highlights a tidbit Bertram had said that they had a private meeting Jane refers to as to Sheriff,, Sheriff mcAllister and the sheriff say Tom also answers the great confidence. The Sheriff tells details of operation in the zone . see the scene 4 times remembered an important detail of RJ that when you open the door the first thing you see is your smile and drawing Jane opened the room the first thing you see is the Sheriff

My top 2 choices have been Ray Haffner and Thomas McAllister, and last night's episode further confirmed my belief.

Several things I've noticed:

1. When Lisbon tells Haffner that RJ did not hurt her, he does not give the response you would typically expect from someone who's genuinely concerned.  Instead of saying "wow! you got lucky! That's great!," he responds matter of factly "good for you."  It almost seems like Haffner wanted Lisbon to get hurt, but somehow the plans got foiled.  Perhaps RJ has a phobia of pigeons and had to leave the house due to all the birds?

2. During the meeting with the 3 RJ suspects, Bertram and Smith look visibly nervous while McAllister is not.  He looked genuinely surprised, as if he has no idea what Jane is talking about.  Perhaps RJ is a great actor?

3. Based on Sophie Miller's description of "Jay Roth," I think we can safely rule out Bret Stiles and Reed Smith.  The former is not middle-aged, and the latter is obviously not in good health.

4. I think the big clue in the last sequence of the season premiere is that Red John is left handed.  On last night's episode, we see Sheriff McAllister walking casually.  His left hand is at his belt while his right hand is swinging freely.  Something off about that.  It's not how normal men walk around. 

5. I think there's a good chance that Haffner is Stiles' son.  I don't think Stiles is RJ, but he definitely knows who RJ is and has a connection to him that goes way beyond what anyone else has presumed.

I don't think that there wasn't a leader.

When Patrick tells about how his former psychatrist was murdered Reede Smith looked to Sheriff Thomas McAllister like what the hell have you've been doing, I am shocked (almost disgusted) by it. 
So I think Reede - with 3 e - ;o))) works for Red John and Call me TOM ;o) is Red John.

You guys are overthinking this.
Put yourself in Heller's shoes. As a head writer, you can't plan too far ahead. Only two suspects of the seven appear in Season 1: Partridge and McAllister. Now that Partridge is out, only McAllister remains.

I can't believe that I missed this before. If you see "Red-Hair and Silver Tape", this is kinda a really creepy conversation :

Mcallister : Who is this guy?

Lisbon : He's a consultant. You want CBI assistance, he comes as part of the package.

Mcallister : (@ Jane) Consultant, eh? What are you, clairvoyant or some gizmo? You've got psychic powers?

Why did he come up with the 'consultant' thing in the first place? Also, when you see the look on Mcallister's face, he's not mocking Jane. He's taunting him..

Yep, he is whistling much better than Haffyboy ;oPPPPPPPPPPPPPPPPPPPPPPPPPp