S6, E3: The body of a young male victim poses a riddle. Was he killed by the physical beating he sustained? By the strangulation he apparently suffered? Or by the gunshot wound to his head? And why would all three methods be necessary? It’s not a mugging, and nor does the victim have criminal connections. Perhaps it was a crime of passion… But when a second victim is found who’s mysteriously linked to the first only by the presence of skin under his fingernails, the answer seems to be that the two young men had no connection other than in death. One victim killed the other. But who killed the survivor?