A lot of people think the one of the seven suspects is RJ. I have many different theories of who RJ is.
1. RJ is not one person, but RJ is a group.
2. I don't think the writers of The Mentalist even know who RJ is.
3. Not sure how much Bruno Heller pays attention to detail but every actor plays their part and their part alone. Therefore I don't think any of them act as RJ. So, what that tells me is that we can't assume any of the seven suspects is RJ because they are not acting the undercover RJ role. My personal opinion is that it wouldn't be fun if one of the seven suspects is RJ and I'm sure many agree. Plus, I'm sure if RJ is one of them, there is way to many details they missed to make the suspects RJ.
4. One day RJ will die. Who will take his place? Patrick seems to be the choice atm.
5. To run off theory number one. Visualize University is the ultimate training program to become RJ.
6. Out of everyone on the list, Bret Stiles is the only one that stands out in my opinion. Even though he stands out, I don't think it's him. May be Bret's number one apprentice or the number one apprentice of the man who ran Visualize before Bret.
P.S There is a picture of members in Visualize in the Visualize farm episode, one of them looks a lot like Brett Partridge but I don't think Bruno Heller would make that mistake. Maybe father?