It seems that there are many people to know the face of Red John. It makes me always uncomfortable about him being only one person. Even one of them betrays him, PJ will know the real name of RJ. Every disciple know RJ different than the other disciples? I don't like the idea of being RJ more than one people but there could be one person who unites and controls them. But he does not have to be the one who killed PJ's family. Timothy Carter was the one who murdered them but at the end there is only one person they answer. Could be Brett Stiles.
