None of these: Grigsby is NOT Red John, but is connected to The Blake Association. Stiles accuses him of being dim-witted, usually happens when a disappointed relative get frustrated and voices their complaints out loud. 

He's made a few off-camera remarks.... Blake needs some plausible brains with muscle, not like Kirkland, Smith and LaRoche. Bad DNA .... Blake needs younger, female and inconspicuous. 

He's high on the totem pole, he's on the move, and not in-the-lead. A good place to be for a young Blake member.