Did they ever find "The Grave Digger" on "Bones"?

If they haven't, I am leaning towards that man that wrote the book on "The Grave Digger" and the female journalist who helped him write the book. The episode I am talking about is "Aliens in a Spaceship." Also I have to add, I think that was one of the best episodes that show has had, the comments that were made were absolutely priceless. The one where Angela says "I don't know, putting testicles on the outside of the body." or something like that, and then Booth says something along the lines of, "Hey, one less reason to wear a suit." This episode made me laugh, cry, and even look over my shoulder a few times. Oh my god, I sound like I'm writing a review!