RJ!

Considering Lorelei was a lover to Red John. It'd be disgusting if it weren't any of the younger ones; Ray Haffner or Brett Partridge & since partridge is announced dead from bruno Heller, that means it's Ray. Come on people

With the next episode revolving around Haffner, I thought this was the right time to put in a theory. 
-From the physical description from Rosalind, Haffner fits the best.
-He is the right age (5x13) 
-In the episode Haffner first appears in Lisbon tells Jane that "He was an FBI agent in the Organized Crime Division, and was an expert in wiretaps and creative surveillance techniques". In the season 1 finale we see that Red John has set up some surveillance to watch Jane and I don't think any of the other suspects have expertise in surveillance. I'm pretty sure RJ has set up other types in other episodes but I would need to look back.
-He works for Visualize and he used to work for the FBI both have some type of connection to RJ.
-Lisbon already thinks that he is Red John.
-This might not mean much but Haffner's first episode was wrote by Bruno Heller and it shown Jane shaking his hand.
-I thought it was strange how he asked Cho if he was smarter than Jane.
-He's an excellent whistler.
-If Haffner was Red John it would explain why he left Lisbon alive.

If Haffner isn't Red John I would say that it's Bertram, but with 5 suspects left it was always going to be tough to decide. I would say there is zero chance that its Reede Smith though. 

I already said how I think it's Haffner for so many reasons and for his feelings towards Lisbon leading to not killing her.
What I want to say to you most is, BOB KIRKLAND and PARTRIDGE are DEAD. Stop making theories about them.
Another thing is, now I'm getting carried off by this Michael Kirkland :P As someone said there is no way we've seen him on the screen, but maybe we did ? IT'S a TWIN, maybe we were sometimes looking at Michael thinking it was Bob ? Maybe in the hospital scene it was Michael, maybe he just uses his brothers position to ge into places like the closed wing of the hospital ? 
Haffner VS Michael:
Haffner just doesn't have the thing, the looks. Kirkland twins (supposing they look the same) have it. They look scary, freaky face, very suitable for serial murderer.
I can imagine now in the last episode the flashbacks from all the scenes where we looked at Bob but it was actually Michael (RJ), where Michael dissappears and Bob shows up.

Like some of the theories on here say, I really want RJ and the "Tyger, Tyger" group to be two separate things. Also, I want RJ to be against the "Tyger, Tyger". This would explain the death of Partridge, is RJ slowly taking out the members of the group? Lets hope so. For some reason I want RJ to be a kind of a sympathetic villain, I want him to help PJ take the "Tyger, Tyger" group down. As for who RJ is, Haffner seems the obvious choice, firstly he fits all the physical description, then there is his relationship with Lisbon. Finally, what interests me is that he doesn't work for the law enforcement anymore, instead he works privately, is this a clue? ("Tyger, Tyger" has memebers of the law enforcement). 

Just an interesting observation. Notice that while Kirkland was moving out of the van he did some sort of swallowing act i.e. He swallowed something that will pass some information to Jane.

Do you really think he wont be ready for this? Remember, he likes to cover his bases. He wouldn't just die without leaving a clue for Jane.

The actor's name is REED Diamond. The complete nome is
Reed
Edward
Diamond.

I see Red everywhere.
Malerio.