Elementary, it has to be Jane.

CBI staff can solve no crime alone.
Jane solves every crime.

Thus, Red John is Jane and will not get caught until Sherlock is brought in. I understand that Sherlock's contract has been completed since the 2nd season of the British show.

Ok even if I dont like it My Theory is that its Patrick Jane. It was especially when his daughter in à hallucination asked him if anyone knows who he is. I think that Patrick may have split personalities and La Roche was on his tracks Being an psycologist.
I also red this interview with the creator, warning spoilers....http://screenrant.com/the-mentalist-season-5-spoilers-aco-172407/
And it got me thinking that its Jane. I really hope that its Brett Patridge or Walter Mashburn or his Dad or an evil twin brother but that wouldnt make sense beacuse the creator wants us to experience something special in this show!
Since I think that Patrick has split personalities I dont think he is aware of that he is Red John and therefore he continues his hunt. That is My Theory for now

I really doubt that Jane is RJ just because I think writers/producers of this show are smarter than that.
Imagine how stupid would all the fans of this show (myself included) feel if they found out that the character they love and sympathize with is actually hartless and cold killer. I know I would be disappointed and feel kind of played because I cared for a character who is a monster.
That is why I doubt writers and producers would go that way.

Jane has to be red john. It is very logical. No one else would make much sense. For the people who think its Brett P. they are wrong. How could someone like him have so much money and have so much resources with a john like his?

Red John has to be someone with extreme manipulation skills. Someone who has great resources and money. It occurred to me that everybody who has been on the show that is an associate of Red John either ends up getting killed or they commit suicide. Out of all of these people who give their lives for Red John seems a bit misguided. Maybe Patrick hypnotize them before they become his "associate?" And if they are ever to get caught they are to take their own lives and never say that Patrick is red John.

Regardless of what we might percieve as Red John. We must look to the facts that the producer of the show would have to have shown Red John in a couple of episodes before they (if ever) reviel who he truelly is. Otherwise fans would be furious if some random person we have never seen before turned out to be Red John. Because the fans need a relationship to Red John.

Out of the movie who would you say you have the most relationship towards? I would want to believe a lot of people would say Patrick.

Wife and child: i don't want to say that patrick killed his own wife and child. Because thats just not the "patrick jane" we came to know and love. However there are many plausible explanations to why his wife and child died by Red John. A lot come to mind but none that i think the producers would like to give reason to if we were to find out that patrick is Red John.

In conclusion i don't want it to be Patrick. I would rather have it be someone else. But logically speaking (doing elimination of the people we have seen on previous episodes)Patrick is the only one with all the resources. And everybody at the CBI is stating that red john has to have great resources, otherwise he would be caught already.

Watched 5x02 last night, and there his daughter asked him if the people he worked with knew who he is?
What does that mean? He is Red John???
I couldn't think of something else.....

She was even smiling when se sat in the car next to him, just like he's fooling you Lisbon, my father is RJ.

And when his daughther says she doesn't care about Red John, he looks very sad. Like he was doing all the killing for his wife and daughter.
His daughter rolled her eyes like on that awnser like she new he had been Red John the hole time. Then PJ looks very sad, especially during the last minutes of the episode, when he is sitting in front of the window.

Jane is in a mental hospital. We are viewing his world through his mind.

The only reasons I chose to accuse Jane is, 1.) I had to choose someone and 2.) that was his voice coming from the back seat of the limo.

Of Course -  This would conflict with the fact that Jane was sitting in the passenger seat of the car.

Even if Jane doesn't end up being Red John, for some reason the producers used his voice as Red John in the finale of last season. 


My reasons for this are the following:

1.) Jane's voice rises in pitch during certain situations, and if you compare these instances to the RJ recording in the limo, they are identical. Everything from the tone, the manner of speaking/pronunciation, and over-all phonetic acoustics of the voice.

2.) I ran them through my voice recognition software (torrented), and although their pitches differ, they have identical baseline signatures. 


Conclusion

I don't believe Jane is Red John, but for some reason they used Simon Baker's voice in last season's finale.