He is Red John.
In the season 3 finale when Jane tells Bertram about Hightower, in the very moment that Jane leaves... Bertram picks up the phone...  to arrange the fake Red John encounter with Jane. (also in order to cover his back).
He knew about the trap and decided to sell O'glaughling in order to force Cho and Rigsby to run away from the place where the encounter should have took place. So Bertram said the phrase about the "man reached the end of his rope".
Bertram had Jane alone without support. Then left, leaving Jane and the fake RJ alone.
You can notice that Bertram the prevous day was reading the same newspaper that the fake RJ was reading at the meeting. It means that Bertram gave it to the puppet and told him how to behave.
He quotes William Blake in a moment of euphoria. Jane told that RJ would have been euphoric about the capture of Hightower.
Hightower is an accomplice of RJ and the confirmation of this theory is that O'glaughling could have shot her instead of Lisbon. He died anyway so why not fullfilling RJ whish? Why? Because Hightower is an accomplice. And everything was set from the beginning in order to create the perfect trap for Jane.

RJ till now is more capable of Jane. He must be older, more experienced and totally able to play dumb. REMEMBER RJ doesn't want to be caught. Why acting in his full potential in front of PJ? To be caught? Sounds stupid. Bertram shows his weakness (like the one at poker) that he refuses to lose. He plays dumb and there is a conversation between him and Kirkland about the fact that they can't trust anybody. Why? Because Gale Bertram is Red John and Robert Kirkland is his left hand.

He is powefull, full of connections with rich and powerfull people, even in the law forces. He appears when Minelli leaves showing that there was a change in the game between RJ and PJ.

Who would you call Red John? The killer, or the master brain? If your RJ is the killer, then I believe that we will not wait too long to have him in hand. But if you refer to the master brain behind all this puzzle as Red John, then we will have to wait till the end of the show. Because I still believe that there is one killer and one instigator. They will first give us the killer and we will realize that it's not over yet and there's a bigger picture. Then shall come the real deal.

I think Brett stiles Made the smile face along time ago on the barn, But I think brett partridge is Brett stiles son. Maybe that's how brett stiles is getting all the information

I am sure PJ is not RJ ! Because when he remembers the scene of discovering his wife and his daughter dead, he is always surprised and at the same time terrified, is just his memory, nobody knows it, nobody can read his mind so he don't have to act in his imagination. The only theory which can be approved is that PJ has serious mental problems, like multiple personality. But it can't be possible, it would be noticed and also his thinking would be affected. Don't you see how many cases ended with charities made ​​by him? He is a good man !!!