I think Gale Bertram could be Red John, because when (i don't know in which episode) they told the place to him and to Craig O'Laughlin, where they will (the team) catch Madeleine Hightower, the killer who was sent to kill her (the killer who jumped down from the ledge) went first to the room, which was mentioned to Bertram, but she brought a rope with her if Craig's (which was mentioned to Craig) room was the real! So this is my theory!