He fits the correct physical description (some of the other characters don't!) He has known Jane before Loreli Martins gave the "shook his hand" clue. He has a soft voice which matches the voice we've heard over the phone several times. Jane described him in his notebook (when he was formulating his list of Red John suspects, before the final list of 7), as "totally macabre". He's the one character in the show which Jane gets the creeps from and calls a ghoul. Partridge enjoys Red John crime cases way too much. He always misdirects him and says it's not RJ when it is, and that it isn't RJ when it actually is. Heller said we'd be disappointed when we found out who RJ is. I think Partridge would be a great candidate for disappointing us because he's in plain sight so often and because he's the so-called "Red John expert" because he's been to every single Red John crime scene.
It's common in many serial killers that they'll try to take part in their own crime in some way, for example the episode when a man who was a serial killer made an entire website dedicated to catching the serial killer. Partridge believes he can't be caught, and he gets pleasure in seeing corpses at crime scenes. Partridge also makes fun of Jane in an episode, saying "going to get your psychic juices flowing?" and he pantomimes a strange portrayal. When he claims to show him a real magic trick and gives him a list of all 7 suspects, he is putting Jane down. Partridge despises Jane, but also thrives on the fact that Jane can never catch him.
Finally, in episodes 1 and 2 of Season 6 it becomes very obvious that he faked his own death. Consider this from Red John's perspective: you have friends in the CBI and FBI. You know that your phone is tapped (he has his way of knowing practically everything.) What is the way that you can both get rid of your bug without suspicion, and make Jane and Lisbon never again consider you as a suspect? You fake your death. They never showed his body. When important figures die, such as Agent Wainright at the finale of Season 4, they always show the body. Showing the body verifies that the character is gone, which they have not done for Partridge. Why else would Lisbon go into a dark house alone? As a top agent she knows better, but to make it so that Lisbon is the only person who sees Partridge, they had to script it that way.
At the end of Season 6 Episode 1 pay VERY CLOSE ATTENTION when Lisbon is grabbed. She is standing to the right of Partridge. She looks away from Partridge because she thinks she hears something. And she is then grabbed FROM BEHIND, which is where Partridge is in relation to her. She turned her body away from him, and he grabs her. In Episode 2 Bertram claims Partridge was DOA (dead on arrival), however, Red John is always two steps ahead and makes things happen. We never see the body in the body bag. Remember when Jane and Lisbon go to jail to see Loreli Martins and they bring out somebody else, but the guard claims it's Martins, when clearly it is not? Red John can change information and make things happen. Jane is caught in a stupor and he is trying to find out which of the 6 people it is, and the last person he would consider anymore is Partridge. Red John is two steps ahead of Jane, as always.
