Hi there, I agree with Brett Partridge as RJ for the reasons already given by others.

One note about the season finale, about Jane's one happy thought and as to how RJ knew it and that Lisbon could somehow be involved?
When Jane spent the night with Lorelei I remember his sound sleeping right through until the next day and wonder whether Lorelei and RJ drugged him and got as much information as they could out of him. His sleep did not seem natural. I think this may explain how RJ knew his happy thought. The question is what else they got out of him. At the time Jane thought he was playing Lorelei and RJ but maybe it was the other way around?

Anyway, just a thought.