go youtube: http://www.youtube.com/watch?v=590v4FCm6WU there is shown the last episode of season 3. Where Jane kills Timmothy Carter, because he thinks he is Red John. Stop the Video at 00:52. Then you will see a man in a red sweater. Kinda looks like Robert Kirkland. I think it's his twin brother Michael. Before this episode was shown in TV Bruno Heller (the producer of the mentalist) said that we will get "a glimpse of red johns real face" ! Well, there he is! Michael Kirkland.
How do you find this theory?
plausible
unlikely