The Homeland security officer who appears in season 5 episode 16
 
and wanted to be in the loop of Lorelei's case.

Patrick always loses he never gets what he needs from the people who know it before Red John gets them i'm sick of it how many more times can he lose before it gets to the point where everyone quits watching this show cause i'm bout there

What about the guy in the red sweater at the food court in the episode where Jane shoots the guy he believes is Red John. If you look up a clip of that scene you will see him seated in a table right beside the man believed to be Red John. He is  in  perfect vision of Jane in this scene and when 'fake Red John' answers his phone to Lisbon you can see him look up as if listening instead of continuing to read his newspaper.When Jane stands up to confront 'fake Red John' the man in the red sweater gets up and leaves but a few seconds later we see him walk past in the background when Jane and 'fake Red John' are speaking. So he has not left the food court but is in viewing distance of the shooting that's about to happen.Maybe it's just me but it's worth considering.

LIKE ALL OF YOU, I AM WRITING TO GET MY THEORY OU THEIR AND TO GET A LITTLE ATTENTION. IT'S HUMAN NATURE. SO HERE IS MY THEORY:
WE ALL KNOW THAT IN RED JOHN'S FRIEND, AT THE END, IT SAID HE IS MAR. OF COURSE THE PERSON THAT WROTE IT MEANT MARS. BUT MARS IS NOT RED JOHN. MARS IS RED JOHN'S FRIEND. ELLIS MARS ISN'T RED JOHN.

Cat!

I had written this before, but could not provide you with episode no. Now, I can.

Season 1 Episode 11 ( 43:15 of 43:25 )

Red John calls PJ in Mexico, ( he is mar episode) and gives the bad man laugh. At a second, we hear the sound of a cat.

Also about the he is mar thing, i believe it is not mar, because there is a very steep curve after the straight line. It can't be r, it is another m. It is half of the next m.

So, it is mam. 

Now, going back to my point, who loves cats in the series? Or even, who owns a cat? (Tigers are also cats, makes sense that RJ has a cat)

i believe all these ideas of RJ being a group of people as false. As we know, Rosalind identify's red john as a short man with specific characteristics, also when he speaks to Jane at the end of season 2, he seems to fit all the characteristics, short, soft, high pitched voice (confirmed in red john's footsteps) at first i accused it would be Kirkland, or Brett partridge , as Kirkland requested updates on Jane when he first joined the CBI, at the end of red dawn. When he first shakes hands with Jane, he has a devious look about him, especially when he says Jane doesn't know him, but he knows Jane. But i realized it was very unlikely to be Partridge, or Kirkland.  reason being is that partridge seems to tall according to description, also in the episode where bosco's assistant is arrested, you can assume it was red john who poisoned her in the flesh judging by the look on her face, but wouldn't they realize if a forensic investigator was walking around in a police suit?  i don't think it was Kirkland because him and Jane hadn't shaken hands until after Lorelei told Jane about it, however, i still don't know why he wanted updates on Jane, and why he hasn't appeared anywhere else in any season. i believe Darcy is an accomplice for RJ because he tells Jane that he has someone in the FBI who told him, but i believe nobody knew except her and her team. Also, she shoots at the car, probably because she knew RJ wasn't in there, she was recorded by Red John and he said 'she's cute, this will be fun' yet RJ didn't do anything to her, and she didn't seem upset by it whatsoever. BUT, i do however have have a theory on red john, he doesn't think of what he does as a 'bad thing' or 'cruel', he see's it as art, or passion, i say this because he kills anyone who pretends to know him. slandered on the media by Jane, he kills his family. gets insulted by James Panser, gets killed. Called a Beast by TV talkshow host, kills her, the list goes on. i don't know who red john is, if i made an educated guess, it would be Brett Partridge, even though i think he's a bit to tall, i can't recall his exact size, his voice fits the bill, and he seems like a big fan of red johns work in the first episode ( even though it wasn't red john) thank you for reading, please respond! :)

I don't know who Red John is, but I am absolutely sure isn't Ellis Mars and Walter Mashburn, because Red John never brings himself at ridiculous position like they.

My opinion Red John is one of them: Brett Partridge, Oscar Ardiles, Ray Haffner.