I agree with Darkjane, theory #2905, that Patrick Jane is Red John.  I have watched
every episode starting with season one at least twenty times.  The writing on the
tile wall 'He is man/mar' is really 'He is mad'.  The letter d wasn't completed when
Red John wrote it in blood.  The episode where Jane was in the mental facility where he
was being released, was shown distorted by the camera.  The wall on the right side
of his room showed the red smiley face.  I hope there will also be a season 7 of The Mentalist.  I can not wait for season 5 to be released on DVD.