OFFICIAL : In episode 4 : Jane's list of suspects decreases to five remaining names.

source :
http://thementalist.wikia.com/wiki/Red_Listed

Well, he did whisper ‘Tiger’ before dying. 
Yes, he did. And that’s another clue that will have big ramifications later on. These next few episodes, essentially the first episodes of this season, all have those kinds of revelations and clues and hints and big steps forward in the mystery. And all will be revealed.

When do we revisit the Tiger clue?
Watch episode 4 and you will get some answers to that in episode 4. I can start very specific now about those. Episode 4 will give you some answers that go a long way to answering that question.

So,according to Bruno Heller , the Episode 4 will contains much clues and answers.

If he isn't Red John, then he is most certainly involved as when Jane showed the video of the 7 suspects to Lisbon, she said to Van Pelt something along the lines of "Jane's paranoid that Red John has read his mind because he knows the 7 people who Janes thinking of". The only way Red John would've known the 7 people that Jane thought it was is if he saw the plan that either Jane created in his apartment OR the one that Kirkland copied when he got two guys to break into Jane's apartment to take photos of the plan, which he then recreated in his office. That is the only way that Red John could have known Jane's 7 suspects because Jane didn't tell anyone about them- not even Lisbon- until he got the video from Red John.

Also, Kirkland from the start has this high-pitched and soft voice which Red John has. I noticed this similar voice in episode 2 of season 6 when Red John phones Jane and has Lisbon, painting the face on her.

I still don't see Kirkland's motive if he is Red John, but he's been interested in the Red John case from the start and had a copy of Jane's plan which makes me think he is either Red John or is working with him...

rossalind harker and dr millers description are the basis for 70% of these theories, bet they're tricks by RJ.

First off I want to say that I don't think Kirkland is RJ but I had to put somebody. Now, In the promo for the next episode (Red-Listed Season 6 Episode 4), there is a man lying dead on the ground that is on Jane's fake list of Red John suspects, take a look: http://tinypic.com/r/f1ej9k/5 and another angle with reede smith in it: http://tinypic.com/r/2v9uiwk/5. Also in the promo Jane is being kidnapped and "tortured" by Kirkland but if you watch closely you can see that the man with the finger Kirkland is going to cut off isn't Jane becuase of the clothes. Take a look this is Jane in the promo being kidnapped : http://tinypic.com/r/okmuet/5 and a look at the man with the finger: http://tinypic.com/r/2ym615d/5 notice that the man is wearing brown pants and jane is wearing his usual grey pants, my guess is that the man on the ground is somebody that was in a previous episode and only appeared once before. I also think that when Kirkland is threatening to kill Jane then Red John comes and saves him. Another huge clue in the promo is the words "watch this episode closely" in huge letters during the promo

Bob Kirkland is not Red John. This is about Homeland Security, and Kirkland is the HS agent on the show. As we know, however, there is more to Kirkland's involvement in Lorelie's case than merely Homeland Security issues, but we're not sure yet what those his motives are. 

Why is Homeland security involved in the case of Lorelie? I believe it is because some of the Red John cases -- here comes my conjecture -- involve human trafficking, which is an international crime that is frequently connected with other international crimes, of interest to Homeland Security. There are two reasons I think this is the case. 

1) In the Red Letter episode, the victim, Hector Brava, was killed just before he was about to give a speech where he was about to expose a human rights institution for their involvement in human trafficking. Apparently, Brava's being blackmailed and subsequently murdered had nothing to do with his speech, but that is questionable, since his murderer stole the notes to that speech. They conclude that Bigalow stole the notes to make it look like that was the motive, where as the motive of the killing was quite convoluted. Could it be that he claimed his motive for blackmail was money rather than expose his involvement in a much greater crime. And if this theory works out, a crime that ultimately traces back to Red John. I'd lie about it too if that were the case. 

Incidentally, Kristina Fry plays a major role in that episode. If she were somehow also involved, it also implicate Stiles, who just happened to know Kristina's whereabouts after she had been allegedly kidnapped. There is nothing saying that Frye was involved in the case she was called in to help solve, but since she already is a questionable character, her involvement in solving crimes has to be questioned. This was in fact, the first case on the show where her collaboration was requested, even though it was her second appearance. 

2) Kidnapping is frequently a part of RJ's MO. I can think of three cases that occur in the following episodes: Red John's Footsteps, Red Sails in the Sun Set, and Red John's Rules. In Red Sails in the Sunset, the kidnapping in question occurred much earlier, but it is in that episode where we learn of Miranda Martin's disappearance; in Red John's Rules (Lorelei appears again in a video) the kidnapped victim is a baby. In two of the three cases, the kidnap victims are intended to be Red John "gifts" -- the are not vendetta or ransom kidnappings. 

We still do not know about the motive of Miranda Martin's kidnapping. We Just know that it was facilitated by an agency that was supposed to care for vulnerable women; and subsequently that Miranda ended up dead. We also know that Kirkland was obsessed with the Lorelei case. His involvement could have something to do with her sister's case also. We just don't know what his personal interest with the Martins's is, yet it is the only RJ case where Kirkland/Homeland Security takes interest. 

My guess is that HS has one set of reasons for pursuing RJ with regard to Lorelei, while Kirkland has a much deeper ulterior motive, a personal motive related to the deaths of Lorelei and her sister. 

If Kirkland really wants to find Red John, then why did he not ask about Red John before he killed Red John's henchman in the hospital?! No one has yet been able to answer this simple question!

And why is Kirkland the only charachter who always wears red (and mostly tiger striped) ties?

http://s22.postimg.org/bsgb6t5s1/Red_Tiger_Tie.jpg