I believed it was Ray Haffner since season 5. Last weeks episode sealed it for me. In a previous episode, Jane said that Sophie Miller was horrible and taking notes, so she used a tape recorder and a service to transcript. Referring to her claim that Red John was "Acrophobic" ( the fear of heights), was actually a mistake of her hand writing. Her horrible writing re-read it wrong when it should have said "Arachnophobia" ( the fear of spiders). A simple reveal whne Hafner jumps at the spider.
