red john is dr wagner. he is a psychiatrist and so an expert of psychology like jane, he might also be a much more accomplished hypnotist then jane. it would make sense also as red john would have appeared in pilot of the series. he let jane catch him in the first episode on purpose because as a superb hypnotist and a large network of accomplices jail is no restriction for him , he might be able to get in and out on will and nobody would suspect him or think of looking for him in JAIL! that's why he used jane to get himself there. that's why red john is always confident that nobody can catch him. nobody would look for him in jail and he would always have a perfect alibi even for times he was out.
he might even have jane under hypnosis when he had a session with him to prescribe the sleeping pills, maybe part of that session was not shown in the episode. would also explain how he know about jane's happy memories etc.
it would also explain how he knows the list of jane's suspects, because they are all people who had something to hide and have willingly or un-willingly helped red john at times, so it would be logical that jane could not eliminate them and red john would know that also.
Roy tagliaferro/ jay roth etc. may have been wagner himself or an accomplice.
This would explain all the clues hints etc. in the series quite satisfactorily.
