Now, a theory I have come up with, is that nobody is Red John. Yet everybody is, Red John does not have to be a person, it can be a symbol or a meaning, or even better a cult of some sort. I do believe that it all started with visualise, and that a few members branched off, and created a new 'cult' one named 'Red John'. This means that anybody in the cult of Red John can become the Red John killer. Further more, Timothy Carter, a character we know little about, could have been one of these Red John killers, but wasn't the one who is terrorising Patrick. It may also help explain how many recorded Red John killings are not related to Patrick's life story, yet some are. Possibly one particular member of the Red John cult is fixated on Patrick. The idea of the cult makes more sense when Red John seems to have so much power over people, to think one serial killer can control so many people to perform his deeds. I think all 'followers' of Red John, are not following a man, but a religious cult, branched off from the idealisms of visualise.
