This "new" serial killer is one of three things   1- The B.A.  2- A Red John Follower/copycat  3- or Red John                             1-I don't think it was the B.A.- they are just blackmailed cops and Abbott says the FBI took down the rest of B.A.                  2- it could be a RJ desciple looking for revenge   but why kill ex CBI agents two years after CBI was disbanded and not just kill Jane first     3-  I pry to God it's RJ and he isn't using the smiley face cause he still wants Jane and the world to think McAllister was RJ and is dead                                 but Red John said he was going to start killing often and Haffner warned Lisbon    and he also threatened Jane          off the top of my head I don't remember seeing one RJ smiley face this season          what if RJ hasn't actually killed anyone this entire series and the real Red John is now killing everyone on the CBI list       every RJ murder is either a copycat killing or by a RJ follower like Timothy Carter or McAllister