Mulder: Roland Fuller was hired by Arthur Grable. He went to the halfway house specifically to find a mentally challenged person.
Scully: Are you suggesting that Arthur Grable hired Roland in order to use him? And are you suggesting that Arthur Grable is not dead?
Mulder: Well, if he had intentions of killing Nollette, Keats and Surnow, why not set it up to appear the least likely suspect?
Scully: Yeah, but by the look of this, he's hamburger.
Mulder: Maybe he staged it. That would explain why his work is continuing on, six months after his "death".