Patrick himself is a potential suspect. Given his complex personality and his tough childhood he might have become a psychopath (Red John). Of course he met a man wearing a mask who was THOUGHT to be Red John but he also killed a man who claimed to be Red John but he wasn't. Patrick as Red John could have hired all these people with out even showing them his face, he has built a great network of friends and connections thanks to his days as a traveller psychic boy and later as a psychic. His wife finds out about his second personality she loves him so she doesn't go to the police but instead asks him to get help from a therapist. Patrick with his great mind engineers a plan to kill her by talking on TV about Red John and so that he could move himself from the suspect category to that of the Victims and then when everything is ready he kills his wife and since he didn't have a mother himself and understands how hard it can be for a child without her mother he decides to kill her as well. When he wakes up in the morning he can't bear what he did so he goes crazy and he gets hospitalized in a mental asylum where he develops his second personality the good one. But he still shifts between personalities without even remembering a thing about his bad personality when he is good, however when he is bad (Red John) he remembers everything about his good CBI consultant personality. So when he is Patrick Jane of the CBI he doesn't know that he himself is the Red John and therefore tries his best to catch this 'Monster' but how could he?
This is a brilliant idea for season 6. Take it, I won't sue.