 A serial killer who kills with his bare hands leaves the bodies of his male victims at the Brown Derby, the Trocadero, and other Hollywood landmarks. Sam profiles the killer as someone trying to rectify some trauma he experienced in his past. The team follows a trail of clues that eventually leads them to a rather ordinary cab driver who does not seem to have the strength necessary to commit the crimes. A search of the man s apartment yields evidence however, that matches Sam s profile to the letter. Sam soon realizes the man suffers from multiple personality disorder. Meanwhile, the imprisoned Donald Lucas continues to taunt Sam while George meets with Bailey where they discover that Sam s father, a scientist, participated in experiments that had deadly consequences.