I'm the fan that has just posted about Charlotte. Now some people believe that Robert Kirkland isn't Red John but here's what I think.

Reason 1 : Patrick clearly states on there first meeting "Do I know you?" as if he should know him.

Reason 2: What if that wasn't there first meeting? What if they have shook hands before, but somehow Patrick has forgotten, maybe when he had the breakdown.

Reason 3: When it flashed back and Robert Kirkland was in that limo with the woman who was talking to Minelli it is clearly a black limo just like the one Wainright was killed in.

Reason 4: Robert clearly knows about Jane's time in the hospital, as Alexa Shultz informed Minelli on the phone.