Guess with less than 24 hours to go I'll spill the beans.

Red John was introduced in the Pilot, but it's not Brett Partridge.

It's Morgan Tolliver.

Pretty obvious once you realize that Tolliver is the Americanized form of Taliaferro. It's a common name in the south, I can't believe after 6 seasons nobody else picked up on this.

Just Google taliaferro, tolliver or any combination thereof.