I also have some ideas too:
First, I don't think RJ is not on the list. If Jane has a vogue list in his mind, I will be ok with the 7 suspects. Here he listed them down in black and white, everyone knows their names. They know RJ is there, sooner or later they can catch them. Nah, that's not a good approach for such a big fish like RJ, whom they have been searching for years. Moreover, the real murder is usually the least suspect in the big picture, I reckon the most plausible suspects in this site aren't RJ.
Second, all the 7 suspects are creepy somehow. If they let the bad guys play the bad guys, that's old school. We will have no feelings for "the one", if RJ is really on the list, except for the happy feelings when justice prevails.
Finally, for the sake of a detective show, I think the more shocking the result, the better, which means RJ'd better be the one we never suspect or even the one we adore - one of the main characters.
The most shocking truth could ever be is that PJ is RJ himself, but it seems to be eliminated. So, the rest share the chance: Lisbon, Rigsby, Van Pelt and Cho. If you read other theories about them, you will find out all of them are good candidates for the RJ role somehow. My bet is on Rigsby. Here is why:
-All the strange posters about him being isolated from the group or creepy.
-He will leave the show soon.
-This truth will fire a lot of question: how can't anyone ever notice this? how can't PJ miss this? what will happen to poor Van Pelt? how does RJ feel when working so close to PJ and playing him around. That's what I would love to watch.
