The murders of two young women near a Phoenix canal in the early 1990s remain unsolved for over 20 years until a team of cold case detectives take on the case. Friday's all-new Dateline examines how investigators used inventive techniques and groundbreaking advancements in forensic genealogy to unmask the killer.

INTERVIEWS WITH: Former Phoenix Police Department Sergeant Troy Hillman, Defense attorney RJ Parker, forensic genealogist Dr. Colleen Fitzpatrick, co-workers of the victims, and others.

The investigation into the mysterious disappearance of Canadian limo driver Dwayne Demkiw sparks an international manhunt for an elusive killer with multiple false identities.

INTERVIEWS WITH: Edmonton Homicide Detectives Brian Robertson and Rob Bilawey, Dwayne Demkiw's friends Kayla Polihronopoulus and Darren Boisvert, and others.