I'm just going to share some thoughts with you, and i warn you straight forward - this post might change the way you look at the whole Red John issue.

Let's start at the very beginning.
In season one we were already given a lot of information about Red John. Bruno Heller is, no doubt, a genius in storywriting and planned everything the way it's going to make sense to us rewatching all the past seasons after Red John is revealed. But nobody seems ever to care about the fact that even Bruno couldn't know how many seasons that would be granted to 'The Metalist' - so he must have kept to possibility to reveal his identity at the any of any season. In simple terms - with every new season there have been more red herrings and misleads. I believe it's not necessary to analize all seasons but the first and the second. We are now down to seven names, and can exclude a whole punch looking at the physical data given. So with the few names left, lay down on your comfortable bed or sofa and rewatch the first two seasons. I believe that there's enough information.

All based on the assumption that the seven names are correct, but I believe Bruno wouldn't lie about that, would he?

As many of you guys already know season 6 episode 1 the desert rose will be about gale and bob kirkland and patrick learning info about wether gale bertlam is in fact red john and if you didn't know already one suspect will die by the end of the episode....http://thementalist.wikia.com/wiki/The_Desert_Rose  also check this http://au.ibtimes.com/articles/494592/20130726/mentalist-season-6-spoilers-premiere-red-john.htm#.Uh......
sherriff mcallister shows up in episode 3 http://www.imdb.com/title/tt3073036/ and gale bertram in episode 2 http://www.imdb.com/title/tt3073034/ so is safe to think that bob kirkland gets killed on episode 1 because bob and gale are the only suspects that show up in that episode and only gale bertram is in the second episode....so if in fact bob gets killed and the sherriff shows up this early in the season i'm pretty sure he will no longer be a suspect thus leaving us with 5 suspects....i'm not putting bertram off the list just yet because the first few episodes are going to be about him,how the team reacts to him being a suspect and how patrick is going to learn information wether he is in fact rj or not.

Haffner's conversation with Cho in "Little Red Book" and his conversation with Lisbon at lunch in "The Red Barn" were to some extent indicative of Haffner's true nature. 

In his conversation with Cho he first reminded him of Rigsby working downstairs as Security, somehow pointing out how Cho might end up the same way if he didn't cooperate with him. Then he started asking weird questions like : "You think Jane's smarter than me?". I remember at that point I was surprised even though no single soul back then had suspected Haffner to be Red John. Of course at the end Cho turned his back on him, but it's the manipulative manner in which Haffner was trying to lure Cho into spying on Jane that interests me the most.

In his conversation with Lisbon at lunch in front of the State House he acted even more artful than he did with Cho. Trying to persuade Lisbon to quit the CBI, constantly bombarding her with all the sad possibilities she might face in the future if she stayed at the CBI, especially Jane dropping out; and the happy ones if she joined him.

The peculiar thing is that he's ever acted even remotely like this in front of Jane. Actually he's done quite the opposite, he let Jane ridicule him.
Haffner is neither too far-fetched nor too obvious. He's a perfect choice.