Steve Eifert

Many 911 calls can trigger murder investigations, but can they be trusted? This show reveals how experts decipher an emergency call to find the truth.

All serial killers commit murder to satisfy their grand fantasies, but the murderers featured in "The Mark of a Killer," take it one step further, committing heinous acts that allow them to extend their fantasies and relive the excitement of their crimes again and again.

After teaming up with a father in search of his daughter, a passionate mental health counselor becomes a mediator between the living and the missing.