The Boston Strangler. The Son of Sam. Jeffrey Dahmer. Every time a serial killer hits, it touches a deep collective nerve of fear- in part because his grisly acts so defy comprehension. Or do they?

Step behind the scenes at the FBI's Investigative Support Unit, where psychological detectives race against time to penetrate the minds and emotions of the most elusive of murderers. Using state-of-the-art science, elite investigators tease apart crime scene evidence and scrutinize victim profiles to construct an astonishingly accurate personality print of the perpetrator- and a good guess as to how and when he'll make his next move.

This time the scene is Rochester, New York, where multiple slayings of prostitutes have left local authorities baffled. Find out how FBI sleuths figure out what makes this dark mind tick- and how remarkable prediction lets them stop the killer in his tracks before he can strike again.