In Chapel Hill, N.C., when troubled teen Josh Bailey goes missing, it leads detectives to a horrific gang-related homicide; experts zero in on how a psychotic, charismatic leader can manipulate others to the point of murder.

In Woonsocket, Rhode Island, women are disappearing at an alarming rate. How do you catch a killer when there are no victims? Our experts analyze the actions of an utterly unsuspicious, highly organized serial killer who nearly got away with it.