Here is a picture you may want to see.....

http://images.buddytv.com/btv_2_800033859_1_434_593_0_/xander-berkeley-in--.jpg

Xander Berkley definitely has the acting chops to pull off the role of red john...
        
We know 6x1 contained a clue that wouldn't be revealed as a clue until later....We watched patrick figure it out....
    The good doctor said she believed red john was lying about his phobia.
The sheriff was startled by a pigeon while saving patrick and said "I hate those things"
  I believe this can be interpreted as rj saying he hated partridge.  Red John probably found Bret Partridge just as irksome as Patrick does....    Red John/Sheriff McCallister probably developed his "hatred" for partridges/birds during his early days in the carnival.
          This is why Patrick is staring so intently at the birds in the park...he's working through this clue....     I believe Nick Nordella while portray a young McCallister in the carnival and his phobia of birds will be a source of ridicule (perhaps from Patrick's father)
       "My son Patrick could do it Tom!  You'll never be as good as he was."    something to that effect......
   By now most of us have read the article and know patrick will be strangling RJ in a park on a beautiful clear day.  (strangling=crime of passion)    
My guess it will be the same park pj and lisbon where sitting in.   And the pigeons there will be a final determining clue for patrick.   Cue the flashback to a young sheriff mccallister failing at filling patricks role in the carnival......