Hotel Homicides: In the 1990s, three woman were killed in three Iowa hotels. In the infancy of forensic testing, how did detectives bring their sadistic murderer to justice? (S3, ep 10)

Murder Down Memory Lane: When a five-year-old describes her mother's killer as a "ninja", police set out to put the surprising killer behind bars. (S8, ep 9)

Left Alone: When 13-year-old Mollie Pittman is attacked and murdered in her friend's Orlando home, investigators are left with absolutely no clues to the killer's identity. (S7, ep 9)

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)

Sin City Slaying: When 52-year-old Martha Doney was found dead in her Las Vegas home, police struggled for many years before bringing the case to a surprising conclusion. (S5, ep 9)

Triple Threat: When a California mother-of-two is found strangled in her home, detectives question whether she was the latest victim of a fledgling serial killer. (S4, ep 9)

Elemental Murder: State-wide panic ensues when a waitress is poisoned in Florida. One of the strangest sting operations in the state's history turns up an unlikely killer. (S3, ep 9)

Silent Night: When a young woman is found murdered in her Oregon apartment on Christmas Day, investigators soon learn the terrifying truth about her killer. (S8, ep 8)

Absent Teacher: In 1993, a primary school teacher went missing after her first day at a new job. Over the next two months, investigators pieced together the sinister puzzle. (S7, ep 8)

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)