1. It's all about syndication. In sorting this out the first thing to keep in mind is that The Mentalist is not a novel or an indie movie, but a rather large business enterprise. Simon Baker, for example, got a $30 million contract for seasons five and six. That only pays out if the show does well in syndication, and the show won't do well in syndication if a Red John is unveiled that kills the appeal of the show. That means that you can be sure Red John won't turn out to be one of the attractive heroes of the show - it won't be Patrick Jane or any member of Lisbon's team. 

2. They may never tell us. The Fugitive was a long running TV hit in the 60s, and everyone thought it would dominate in syndication. It flopped in syndication because the final episode solved the mystery by allowing the protagonist to finally catch the one armed man who had killed his wife. Once the mystery was solved, no one cared about seeing the reruns. That has haunted producers of long running TV mysteries with long running plot arcs ever since. You will remember that The Sopranos ended with a deliberately inscrutable and vague ending so as not to put a cork in it. The producers might make that same choice here.

3. There are lots of characters it could be. If they choose to name a Red John, there are lots of candidates left open. It could be anyone from Brett Partridge (seems a bit young and light, but who knows) to Ellis Mars (ditto, but he could be playing dumb), to Virgil Minelli (a bit too likeable, but not so likeable or core that he's out of bounds), to Brett Stiles (certainly capable of it on several levels and definitely twisted enough) and on. It's a fools game to think viewers can nail it with certainty this far out.

4. My gut - go with the paranoid choice. I like Robert Kirkland as Red John, although I recognize he's just one of many possibilities. He meets all the essential criteria, he's the right age, he's figured into the plot appropriately, and so on. Most importantly, to me, it fits into the zeitgeist of the age, which is paranoid suspicion of everyone in any kind of power. Who better to be a deranged serial killer than a Homeland Security operative charged with protecting us from evil enemies? Who could be better positioned to stifle investigations than someone who can reach out to all the black ops operations of the most powerful government in world history? Because of that zeitgeist, it can be done in a way that doesn't kill all the suspense - yes, Red John is unveiled, but we can be left wondering what even darker conspiracy is left in place that nurtured and protected such a monster.

I am not sure who RED JOHN is but I very sure that HE is NOT KRISTINA FRYE. WATCH the last episode in SEASON 2 - Red Sky In The Morning.

In the event where PJ was saved by Red John from the two insane students, you can listen to his voice. Though RJ may sound feminine, he definitely sounds like a MAN. Now when he mentioned "Roll Tide", which in the event was the one that Kristina Frye said to the waiter in the start of the show, it was actually because HE WAS LISTENING TO THEM WHILE THEY WERE DATING. Look closely at the scene and shots when PJ and KF were talking to the waiter, during the time before she mentioned "Roll Tide", you can see a man wearing a black suit on the table next to them. He has black straight hair. You would see that in the left side of the screen, near Jane. He was actually interested in ROLL TIDE because the waiter mentioned the phrase "CRIMSON Tide" where his uncle belonged to. CRIMSON, a shade of RED. You can check the episode, see for yourself. Kristina Frye is not RED JOHN.

Watching over 4 seasons of "The mentalist" has provided us with a quit handful understanding of Bruno Heller's strategies.He's an Expert at distracting us from the truth lying in front of our eyes; so according to his methods of scripting I think he's going to surprise us as he always does.but considering PJ , BP or BS as Red John isn't much of a surpise cause we've all thought about it. I believe RJ is someone we see each episode but can't think of him(if he's a man) as RJ.someone like Cho or Gale Bertram.

Just Wanted to put it out there anyone remember Dr Roysten, the hypnotist. he was in season 1 episode 18 russet potatoes, he has the charming look, he also has the ability to read people abit similar to the way patrick jane does. I just find it intresting however im not sure if he could be red john, i dont think red john is patrick jane!

Ellis Mars

1.White male
2.Mid 30s or older
3.Approximately 6’ tall
4.Brown hair
5.Shook hands with Patrick
6.Mentioned Patrick’s tragic loss.
7.Has attached himself to at least one CBI investigation (helping Patrick)
8.Business card with a red, tiger-faced image from which light is emanating
9.False psychic
10.The name ‘Ellis Lomar’ on a dossier on Bosco’s desk
11. written in blood on the wall: "He is ma..."  He is Mars!
...

BOB KIRKLAND of the homeland security.

it's not bret stiles. when Red John was following Darcy at a convenience store, it shows that the guy is not a known fellow. Everyone knows Bret Stiles and people would have been starring at him at the store for sure.