I have decided to make a theory using clues purely outside the show(from interviews).

Clue 1: Red John is on the list (Source: TvGuide)

Clue 2: Red John has been there from the beginning of the show (Source: Bruno Heller)

Clue 3: We see a glimpse of the real Red John in the Season 3 Finale. (Source: Bruno Heller)

Clue 4:Red John likes cold. (Source: Bruno Heller)

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1. There are 7  people on the list.

2. Then we're down to Partridge, Kirkland and McAllister (Red Dawn could be interpreted as the beginning)

3. In Season 3 Finale, Nighttrain probably caught the most observant spot in the history of the show.

Brett Partridge can be seen walking his dog. It is a glimpse. The images are in the comments of the link below. I don't think Bruno Heller would make it obvious, so I expect a lot of people to say "Haha, that's not him." He's got a watch on his left wrist, but that's not much...

http://www.whoisredjohn.com/See-a-theory-Red-John/11555#disqus_thread


4. Ok, to confirm Partridge is Red John, we need evidence he likes the cold. Isn't it interesting then, that they put him in the middle of a desert in the season premiere? A desert with many, many flies? Insects thrive in warm environments. And ...Jay Roth has "Acaraphobia"...or "Acrophobia". Well acaraphobia is a fear of insects that bite.  Using subtitles won't work. It still says "acrophobia" but, I'd expect Bruno Heller to pull a trick like this. Phonetically they are exactly the same word.