Marriage struggles lead to a love triangle and the brutal murder of Rozanne Gailiunas in 1983. Years pass before a shocking and unexpected killer is finally caught.

Two residents of a quaint Seattle suburb die suddenly in 1986 and investigators learn they were both poisoned. A year goes by until police catch the killer.

In a quiet LA suburb in 1988, Robert Samuels is ambushed and shot dead. As time passes, investigators look closer at Samuels' widow and a greedy motive is revealed.

Louise Talley is raped and murdered in her home in 1991 and Anthony Wright is convicted for the shocking crime. Decades on, new technology sees the true killer caught.

Anthony Tomaselli is found dead in his home in 2015. Years later, his daughters begin feuding over a love triangle and a shocking family secret comes to light.

Police suspect Sherry Rasmussen's husband after she's shot dead in 1986. Two decades on, DNA testing helps investigators find the killer directly under their noses.

FBI employee Melissa Mooney is strangled to death in 1999 and all the signs point towards her abusive ex. Police hit a dead end until an unexpected lead revives the case.

Police fail to identify Kathleen Lipscomb's killer and the case goes cold. However, a suspect comes to the fore several years later and the murderer is finally caught.

Police hit a dead end after Gary Triano is killed by a car bomb in 1996. Secret love affairs and financial receipts emerge 13 years on, pointing at an unexpected killer.

LaNell Barsock is shot dead in 2010 and the victim's friend goes missing. Police use a popular TV show to locate her and uncover the truth, years on from the crime.

Anna Hlavka is sexually assaulted and murdered in 1979 and the case goes cold for nearly 30 years. A shocking turn of events sees the murder linked to a serial killer.

When judge Vincent Sherry and his wife Margaret are killed in 1987, police struggle to pin down a motive. Years pass before a link to Mississippi's Dixie Mafia emerges.