I don't think anyone on Jane's "suspect list" is red john.  I think red john is Bob Kirkland's twin brother.  Bob Kirkland told of how they both grew up with an abusive father who physically and mentally abuse them and their mother.  He told of how their mother committed suicide with a razor blade.  His twin brother seem to be the only one we know of, who is damaged enough to be a serial killer.  I think he met Bret Stiles and he joined visualize which helped him kick his alcohol addiction and gave him an amoral code of inner strength.  Bret Stile pointed Jane to the house Red John was holding his "psychic" friend.  I think Jane met him very briefly and he was in disguise.