I still believe that Haffner would be the best candidate for RJ.
 Anyway, the show is over and that's the decision of Heller. Should say, the ending was really disappointing but the overall show was good. There were many interesting episodes. At the end nobody cared about the identity of RJ anymore and that's OK, because it was obvious that nobody may be so cunning in this era of technology. Red John was smuggling in the houses of people and killing them and no camera recordings, no neighbors... just ridiculous. So, lets say that we watched a sometimes good sometimes bad detective story, where one of the cases was about the notorious killer red john. Obviously they could come up with an interesting ending.