Alright, forgive the grammer, I think it's Virgil Minelli because RJ has to be someone who is older than PJ by close to 20  years because in season 1 episode with Rosalind Harker (Alicia Witt as the blind woman who plays piano), the cop at the end tells him that RJ was a friend of his dads a long time ago and the cop was at least 30, making his dad at least 50 (probably).  As the Director of CBI and Lisbons boss, he was the one who hired Jane in the first place and he's able to watch over his pursuit of RJ in the beginning. 

After he leaves the CBI, he assists PJ with tracking down RJ associates, and as a cop he would be privy to investigative techniques too.  RJ is obviously just as smart as PJ if not smarter (Holmes and Moriarty anyone?), and could easily tone down his intelligence around PJ if he wanted.  He's also divorced and has plenty of free time now.  Sorry I'm light on facts but have had a gut feeling about him since the end of season 1