I need to make a correction to my previously submitted theory #146.  I inadvertently stated that Joan and the Reverend appeared in Season 2, when they actually appeared in Season 4 Episode 1.  However, I firmly stand behind my theory.  Red John suspects, as well as victims, have been diverse and scanned the course of many years.  Who better to orchestrate such an elaborate operation than a Cult leader?  Joan and the good Reverend could very easily have manipulated the Carter's to do their will.