I know the true identity of Red John, because I'm Bruno Heller's cat and he confides in me everyday.

Michael Kirkland is Red John, and Bret Stiles is the Kirkland twins' true father. Brett Partridge is their mother, Reede Smith is their evil sister, Bertram is a poor uncle of this crazy family (must be Stile's brother because you have 'Bret' in 'Bertram'), McAllister is the loyal guard dog and... well, let's say Haffner is the goldfish.

Ah, family business...