Just thoughts i Had To throw out of my head.
        
Couldn't a smart guy like Patrick Jane predict all of these facts and theories we are sharing here, and put together a logical story ?
-Red John started killing in the late 80',
-Jane heard Red John's voice,
-Rosalind Harker could be the girl Jane and his father tricked,
-B. Partridge's strange behavior towards Jane,
etc, etc ...

He would probably know, by analyzing all the suspects, who could probably manipulate with people so easy, be a cold blooded killer... I mean, he does this all the time in the ordinary murder cases.

Who could be Red John from all of this we saw in these 5 seasons ? -Depends on what story would B. Heller give us as finish. With a good detail in the end, everyone of these suspects could be Red John. Now, we can only assume.

My personal choice is B. Partridge with B. Stiles having a roll in all that mystery.