I dont really have a theory of who Red John really is, Ive thought it could have been several characters over the years, this is more about how i think the show will end ! I dont think jane ever will catch Red John whoever he may actually be. RJ(Red John) has always been one step ahead of jane from the beggining and i think he always will be that ope step ahead ! Time after time Jane thinks hes going to get him and RJ has ultimatly got some great plan to evade capture and make Jane look like a fool ! The last episodes of season 3 and season 4 are both great examples of RJ being smarter and getting the better of Jane !

As to who RJ really is i have no clue but I deffinatly dont think its Jane OR any of the other CBI Team