This is why I don't think Red John could be Bob Kirkland. It's very simple really; before Red John killed Lorelei, he already knew the 7 names Jane had narrowed down - this goes without a doubt, or else how did he make the video? Bob Kirkland and his team broke into Jane's aerie to collect what information he had on Red John after Lorelei's death; if Kirkland is Red John, what would be the use in breaking in and seeing what Jane knows if Kirkland already knew the 7 suspects?

Someone else here mentioned that Sheriff McAllister couldn't be Red John because he would have known that Van Pelt worked in CBI when he approached her in S1E2. So obviously Jane's list is bullshit. So who wouldn't know that his list is bull? That's gotta be Red John.

Just a theory but I think we can eliminate Bob Kirkland from the suspect list.
Why? Well first because it would be too obvious, i mean, Bruno Heller clearly wants us to see him as a suspect and it would be way too easy.
And the second thing is related to the "killing in the hospital" part. It doesn't fit RJ MO, I mean, killing like this is almost too soft for RJ (remember when he killed loreleil, it was supposed to be a "soft murder" because he liked her).
And here, Bob Kirkland just kills in the hospital, with people around and no blood, it does not look like Red John at all.

Let me know what you think about it!

I believe RJ is Bob Kirkland
based off of these ideas; he broke into Jane’s office, Occam's razor which is
bought up in the episodes (discreetly and mentioned in a few) suggest that it
is him based off of its principle the hypothesis with the fewest assumptions should be selected (the simplest
answer should be chosen), killed Lennon in the hospital after asking if he recognizes him (kind of
puts it you off the idea of it being him because it’s not his style, but if you
think back Red john has killed and messed up before because of an event that
happened that was unplanned for) knew that Jane was in the mental asylum and
could have gotten hold of all his therapy sessions (possibly even the therapist
herself which seems less likely) which would have informed him of the happy
memory. Even with this evidence there is still no definitive proof that it was
him and I am open to all suggestions (unless someone says Patrick that is just
a stupid comment and should not even be said it’s not on the list and Heller
said its someone on the list therefore not Patrick)

it's definitely Bob kirkland because he's the one who broke into jane's place to get pictures of the scheme jane mad to find who is RJ. there is no way RJ could know the list jane made except if he had all the clues jane had. besides Bob told Lisbon once that he had a circus life and that he considered himself an american for travelling everywhere with his family. and that is a leek to find out how he could know about jane's happy memory back then.  

If Red John is turns out to be Kirkland, then this will be a serious letdown....I will blame laziness on the writers for choosing Kirkland as Red John.....After 6 years of watching The Mentalist, I would want Red John to be someone who had potential to be Red John but was not one of the favorites(like Partridge or Stiles).....After the revealing of Red John, I would then want to rewatch previous episodes to see Red John and how he acted and what dialogue he used especially with Patrick ....Wouldn't it be a letdown if Stiles, Bertram, Kirkland or Partridge ended up being Red John.....Partridge is everyones favorite but I want shock and awe when Red John's identity is being revealed.............Can you all just imagine if Mars or Marshburn  turns out to be Red John............

Think for a second, look where PJ is investigating: open windows, on an easly climbed roof.

whole season we see him being sneaky and closing his door making sure no one can enter (yeah right with an easy lock)

he is fake investigating, he is playing red john again like he did when he 'gave up' and left the CBI being a drunk.

think about that whats more surprising then playing the same trick that didnt work? he would never guess he will play the same trick again.

What u think?

I am in school and I have just realised something about Bob Kirkland. I think he is a good guy and trying to catch Red John. Only he is trying to catch Red John before Patrick Jane does.
Red John probably has done something to Kirkland which is why he is after Red John.

I also believe Bob Kirkland knwos exactly who Red John is...

Red John attempted to kill John Lennon but failed. Bob Kirkland knew that if John Lennon survives then he will tell Patrick Jane and the police everything about Red John and possibly who he is. So Kirkland had to kill John Lennon before he says anything....because Kirkland knows who Red John is and doesn't want anything else to find out.

So yeah, I think Kirkland is a good guy and is trying to find Red John too. I hope to see more from him in Season 6.