Deadly Forest: The tragic story of 17-year-old Michele Avila, who was murdered by two school friends in the Angeles National Forest in 1985. (S5, ep 1)

When Evil Strikes: Detectives race to solve the murder of North Carolina factory worker Jonathan Blackwell, whose body was found two years after he disappeared in 2004. (S5, ep 12)

Little Boy Lost: When the body of 11-year-old Christopher Alan Brown was found in the Flint River in 1985, it took almost 20 years for evidence of his murder to be found. (S5, ep 11)

Dangerous Fortune: Police are baffled when the bodies of fortuneteller Ha Jade Smith and her daughter Anita Vo are found with white paint covering their head and hands. (S5, ep 10)

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)

Manufacturing Murder: In December of 1997, the bodies of three men and a woman were discovered in a Florida manufacturing plant. Who killed them and why? (S5, ep 8)

Deathbed: Three decades after a man is found dead in mysterious circumstances in San Diego, forensic advances finally identify his highly unlikely killer. (S5, ep 7)

Phantom Predator: A look at how detectives uncovered the shocking identity of the South Side rapist, a man who terrorised the women of Missouri for over six years. (S5, ep 6)

Burning Fury: In 1988, Robert Haugen was found murdered in his apartment. Two decades later, a surprising culprit with a sadistic dark side is brought to justice. (S5, ep 5)

Last Resort: A shocking culprit is revealed when police investigate a fatal acid attack on a Florida hotel manager. (S5, ep 12)