Hi folks :) First of all: RED JOHN is NOT Robert Kirkland ;)
Come ooooon, it would be toooooo easy

My opinion:

Robert Kirkland was very eager getting involved in the Lorelei Martins- case. I think, Kirkland hypnotized Jason Lennon some time ago, so he could tell Lorelei about the rape and the following murder of Miranda commited by Red John personally.
When Lennon answered his question, if he remembers him, with "yes", it was obvious he had to kill him, to prevend Lennon from accusing him.

Maybe Kirkland was behind the murder of Miranda, but i think that would make him the next target for Red John

What do you think? :)

(Sorry for my bad english, im not from the U.S.^^)