The theory written by "hammrn" is super - Danny could be RJ. But Bruno Heller said that RJ IS on Patrick's list, so not Danny.
The body of Partrige doesn't vanish after they found Lisbon, so Partige dies and he can't do a come back.
My opinion is that Ray Haffner is RJ. He didn't kill Lisbon because he likes her, and he has a similar character like Patrick.
