Timothy Farragut.
He is the man that Bret Stilles allegedly killed (officially car crash caused by alcool) to wrestle control of Vizualise. Are we really sure he is really dead?
As the first guru of Vizualise, he must have many of the qualities Red John exhibits. He must be smart, well educated, good at reading people and a master manipulator. Pretty much like Red John.
He is also a cult-like figure, exactly what Red John appears to be in the eyes of his accomplices.
I expect him to have the dirt on Bret Stilles: he tried to kill him after all and killed Sheriff Elliot Elswit to cover his tracks. He is therefore blackmailing Stilles which explains the connection between Stilles and Red John and Red John's access to vast wealth (he offered Jane a whole new identity).
