The mask could have been used by the killer to dehumanize the vi...
Sweets: The mask could have been used by the killer to dehumanize the victim, allowing whoever decapted her to distance himself form the ugly reality of her death.
Dr. Tanaka: Mmm, you are entering the realm of psychology, an field of unverifiable speculation. Perhaps I could be of further help to Dr. Brennan.
Sweets: Sometimes I hate hard science. I know that seems immature, but thats just how I feel.