Okay. My best friend and I have decided that Lisbon is a reasonable suspect.  I think that it is Bret Stiles says that what Red John does is "a form of love." And Lisbon cares about Jane.  Maybe Lisbon was just trying to protect Jane.  None of Jane's tricks on Red John work, and he always tells Lisbon. It is logical but she seems so nice! So did O'Laughlin. Think about it.