Blood In The Water: In 1980, a teenage girl was brutally murdered in her Colorado home. But in her last moments, she managed to leave investigators a clue to her attacker. (S6, ep 9)

Brute Force: In 1987, Kentucky police discovered the body of 20-year-old Corinna Mullen in the boot of her car. But it would be many years before the case could be solved. (S6, ep 8)

Stone Cold Killer: In 2000, near Anchorage, Alaska, Genevieve Tetpon was found dead from a brutal attack. It wasn't until 2009 police finally made a breakthrough. (S6, ep 7)

Hometown Homicide: On 17 January 1980, in the town of Hemet, California, 67-year-old Elizabeth Crossman was murdered in her home. But it took 33 years to convict her killer. (S6, ep 6)

High School Homicide: In 1989, Indianapolis high school student Amy Weidner was brutally killed while she stayed home from school. But who would want her dead? (S6, ep 5)

Death Comes Calling: Beloved grandparents are found murdered in their home in Oregon. Are they victims of a spree killer, or was their murder carefully plotted? (S6, ep 13)