THE THEORY: RED JOHN IS 'MANY': Bertram + Kirkland (+ maybe Partridge), + many other helpers/disciples.
I am sure that the words written in blood when Jared Renfrew was killed, is written by Renfrew and is "He is many".
If you were bleeding to death, and you new the killer was called something like, for example "Martin" etc., would you waste time writing "He is" in front of it? Wouldn't you just start writing "Martin"?
Even if he was writing "He is Mary" or something like that, he would just have written "Mary" right off the bat. Anyhow, we are all sure Red John is not a woman.
So one theory is that Red John is more than one person, plus many other assistants/helpers/friends/tools/fools or whatever you want to call them.
I would say Red John is: Bob Kirkland, Gale Bertram and maybe also Brett Partridge. A "killer Committee" of (at least) 2 persons. That way, you can easily explain the inconsistencies between the different 'versions' of Red John as they arise throughout the series. For example Rosalind Harker says Red John is just below six feet tall with short hair (fits both Kirkland and Partridge), he likes reciting the poetry of William Blake (fits Bertram), etc.
This is how Red John can be both short and tall, or have hair and also be bald, or have a high-pitched voice and a low voice, etc.
I would say it is also highly likely that most of 'his' helpers (like Lorelei) are also under the impression that there is only one Red John.
How did 'they' know about Jane's happy memory? What about his psychiatrist Sophie Miller? When Jane had his breakdown - which must have been the one time in his life in which he was not in control of himself - he could have told her at her request, possibly without remembering. It is highly likeley that Red John was keeping tabs on Jane at the time and maybe he got access to their conversations somehow. Sophie was not above criminal behaviour, as we remember.
How did they know about Jane's list of 7 suspects? I can't remember if the guys that broke into the loft did so before or after Lorelei's death, but I think they did so before that. And we see Kirkland painstakingly duplicating Jane's research.
So my bet is: Kirkland and Bertram are BOTH Red John.
