down to 5 suspect, turned out the most obvious suspect, Agent Kirkland is just some Dexter kind of guy who had personal vendetta with Red John. So, here's my theory Agent Smith, Sheriff McAllister and Gale Bertram obviously a part of their 'secret powerful organization' but I think none of them were Red John, especially Agent Smith, cuz he killed Agent Kirkland in front a witness, Sheriff already proved that he didn't afraid of height and Gale is too close to CBI so I dont think he's Red John, which leave us with Agent Haffner and Visualize n cult leader Bret Stiles, but I'm gonna go with Haffner cause Bret is too old, he's probably the leader of the whole 'secret powerful organization' but Agent Haffner is the man who painted the red smiley aka Red John.