CBI Ron - Season 1, Episode 16. 39 minutes and 47 seconds into it, the bomber is looking for Van Pelt and temporarily blinded Jane to kill Jane. They are in the parking lot at this moment and the bomber has his gun drawn. The lighting is very good and CBI ron pulls up right beside him with his window down so he can clearly see, and looks right at the bombers drawn gun in the CBI parking lot. To any other CBI they would immediately draw their weapon or if they didn't have one, go and get one. Instead CBI Ron looks right at it, and at the bomber, and drives away appearing scared. So, obviously, in some way CBI Ron is a bad apple. He's a recurrent "extra" and has a bunch of clues pointing to him being an accomplice or red john himself although that's less likely.

Anyone could be Red John besides a few obvious people like Jane or Lisbon, the rest of the team, etc because they are on the other side of the world when red john kills someone for instance in several episodes (one he kills a hooker and a pardoned fugitive in Mexico while the entire team is back at headquaters, only Minelli is away at this time, yet I don't suspect Minelli just for this one small instance, because I haven't seen enough episodes with him in it. He does fit the bill though because of his age, and love of politics since he's in a political job. Which would explain why Red John is always watching the media. But for now, I know that CBI Ron has about a 85% chance of being a bad apple, and probably linked to Red John in some way.