Gale Bertram can be Red John.

First of all, Rosalind was in a defensive state when CBI accused Roy for being Red John, so her description of Roy might be a lie. Or, Rosalind was told to describe Roy that way by Roy, we don't know.

We also see that from the list. Gale Bertram is on the list despite he is bald. This means Patrick doesn't take the description of Roy by Rosalind into consideration.

The only thing he takes into consideration is that he has shaken hands with RJ. This is true because Lorelei said that when she was super angry.

Now, let's have a closer look at season 3 finale. I am a fan of Timothy Carter character and my favourite episode so far in mentalist is season 3 finale.

To understand season 3 finale better, we first visit season 4 episode 1.

1) Ron Deutsch, the security guy who removed the gun and cell phone from Timothy Carter's body, is found dead. 

He was asked to remove them. And in the end, he was killed to make sure he tells nothing.

The question here is: Was he planted there before the meeting to remove the stuff, or was he a regular guy working there and when it was understood that meeting was to be held at mall, a guy of RJ told him to remove the stuff in exchange of huge money.

I think he was a regular guy and maybe they offered him a million dollars. This way he accepted it.

Now let's finally go to season 3 finale.

2) It is only a moment between Timothy Carter's death and security guy's removing gun and cell phone. This can only mean one thing. The deal was made before Timothy Carter died, possibly when Jane and Bertram arrived at mall, or within few minutes after that. Security guy was planted before meeting or deal made after meeting, doesn't matter. 

This only means one thing. RJ knew that Timothy would die. 

How does he know that? If Jane had never met Timothy, Timothy would just drink his coffee, read the newspaper and leave the mall.

So we look at the reason why Jane and Timothy met.

3) Jane spotted Timothy because he made the phone call with Lisbon. 

Why? Because Craig O'Laughlin was dead and Lisbon used his phone to call last dialed number.

So, if Craig O'Laughlin was not dead and killed Hightower, Lisbon, Van Pelt, Jane would never spot Timothy and he would not die. This means that O'Laughlin had to die that day.

4) Craig O'Laughlin died because Jane realised that the real mole was O'Laughlin, not Bertram.

Bertram: You just sound like a man who has pushed himself too hard, who has reached the end of his rope.

This was the reason why Jane understood that the mole was O'Laughlin. Without this sentence, Timothy would walk again.

Now, Timothy was there to die, but I doubt he was aware of it. But the plan of RJ was that Timothy would go to mall, talk to Patrick Jane, and Jane would kill him. And only one thing would make this come true, that Jane realizes that the mole is not Bertram but O'Laughlin. And without this sentence, it would never be possible.

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I have always thought that there were 2 moles in CBI. Now let me show you why. I had written theories about it before, but could not find link, so this is a re-write.

The assassin takes fire stairs, goes to Bertram's room, puts rope and stuff on the bed and just waits. And when Cho and Rigsby arrives, she is not surprised at all. She just smiles and jumps to death. How do you do that, if you weren't expecting it.

This means that RJ knew it was a trap. Why? Because both O'Laughlin and Bertram were moles ( Or Bertram is RJ). Two different hotel numbers coming to RJ, meaning it was a trap.

So RJ sent an asssassin with rope, and Bertram used a sentence with "reaching end of rope". And this way everything happened according to RJ's plan.

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Now I want to tell another reason why Timothy was there to talk to Jane and die. It was a historical meeting, and hence planned before. It was very important for RJ, so the content of the chat must be important too. RJ can't just tell him to go there and improvise. Whatever Timothy says, it must be RJ's words. So either:

A) RJ and Timothy practiced it before. RJ told Timothy what he should say and also how Patrick's wife and child smelled.

B) RJ was there, listening, telling Timothy what to say through a bug in his ear. This can also explain why Timothy answers Patrick's questions with 2 second delay and stopping here and there. If this is the case, Bertram could be directing Timothy his speech.

I find first option more likely. Either case, this was a very planned meeting by RJ.

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With Bertram's key role in this episode, even with one sentence, I think he is more likely to be RJ than anyone.

fake red john in season 3 finale : I've been thinking , new face , new identity. 
kirkland has been red john's new face and identity ( long before season 3).
that is why he asked jason that if he seeing him before.

I´m not sure but it won´t surprise me if Kirkland was Red John. People say he can´t because it´s too obvious. What if the writers are making Bob look too obvious so people think he is not Red John but he really is? You know, hiding a truth inside a truth so it can look like a lie. Also, Bruno Heller said we will be dissappointed to know who Red John is. If Bob Kirkland really is Red John people will be dissappointed because it was very obvious. 
I don´t really think it´s him, I think Kirkland is looking for revenge against RJ or he works for him, but  I can smell the trick that the writers are playing.

Maybe too obvious to be him (especially due to the William Blake poetry thingy), but I think out of the 7, he is most likely.
I think that Sophie Miller (Jane's doctor from psychiatric ward) is probably involved with RJ regarding Jane's old memory.
I can't see Partridge having the connections and power that RJ would have to have.
If RJ is Kirkland, why would he break into Jane's room for info when he had already rounded down the 7 suspects (as proved by Lorelei being alive (and don't give me any of that multiple recordings/cutting crap) before Jane got there himself. Also Kirkland seems waay to obvious, my theory is that maybe he has personal experience with RJ, wants his own revenge for something and wants to beat Jane or anyone else to it.
Stiles clearly has the ability to manipulate people in the way that RJ seems to, but in my eyes he doesn't have the right kind of personality. He is one of the most likely people I think, but again it may be too obvious, as his connection with RJ has not been hidden.
Haffner could be involved with Bertram and/or Stiles with regards to RJ, as Bertram assigned him to RJ case perhaps to find out exactly how much they knew. Or there could be some kind of visualize connection between Haffner and Stiles, if Stiles is RJ, Haffner may have been keeping him in the loop as Haffner is shown to be open to manipulation with visualize as proof.
I don't really have anything to say about Sheriff McAllister or Reede Smith, other than I would be disappointed if either of them turn out to be RJ, as I think it would be quite boring and I doubt the show's creators would choose anything so dull.
These have just been my ideas, and they show that I don't really have much of an idea of RJ's identity, but please comment if you have anything to question/add