In Season 4 Episode 16 you can clearly see that Bret Stiles is Red John.
As Van Pelt visited Bret Stiles in the Prison , he had helped her with the "mentalic-"red-cloud" trick. because she was annoyed about her renter.
Brett Patridge, Kirkland, Ray Haffner and Lorelei were the disciples from Bret stilles, which is the Real Red John.
Sorry for my bad english
How do you find this theory?
plausible
unlikely