From a writing standpoint, and from the beginning of the first season, I have said Red John was Rigsby. He is the perfect choice. His 'Red' name comes not from blood, but his attraction to redheads. Over the seasons he has revealed enough about his past to suggest that he is a likely candidate for a serial killer. Abusive alcoholic mother, traumatized in school, awkward, intelligent, violently repressed, white male, mid thirties, and drawn to be near or involved in criminal activities. As part of an elite investigative team (first arson and later CBI), he could have access to scenes of unimaginable carnage, yet pull of the perception of being there merely because its his job. From said job, he could also watch Jane and monitor the investigation. I could be wrong. And I'm not sure I want to be right. But Rigsby is the likely candidate for RJ. And if it isn't him, its likely to be Van Pelt working with him.
