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.

Lt Joe Kenda spent 23 years in the Colorado Springs Police Department, where he amassed a lifetime of memories catching killers and helping solve close to 400 homicide investigations. The vivid memories are brought back to life in this hourlong series, as Kenda reopens his `Murder Books' for viewers - folders in which every detail of his murder cases is held - to revisit the most disturbing cases still haunting him today. As he details the process of how he solved the crimes, Kendra also embarks on a personal journey, coming to terms with long-suppressed nightmares. As he says, "I don't want to tell these stories. I need to".