Series exploring some of the most baffling and challenging investigations in modern law enforcement. (S8, ep 3)

Death and Taxes: A look at how police solved the murder of 58-year-old tax attorney Ashley Pollow, who was strangled and burned at his Florida home in December 2010. (S7, ep 3)

Death of Innocence: Kenny Conrick was just eight years old when he was abducted and murdered in Gary, Indiana in 1979. Who would want this innocent child dead? (S6, ep 3)

Deacon's Demise: The notorious 'South Side Rapist' terrorised St Louis in the early 90s, but it took several years before the police were led to an unlikely culprit. (S5, ep 3)

Blood Trail: A tiny clue leads investigators to the unlikely man behind the murder of 22-year-old Theresa Wesolowski, who was found stabbed 46 times in Germantown in 1999. (S4, ep 3)

Innocent Bystander: When a drug dealer and his girlfriend are found murdered in their apartment, a bloody print leads investigators to a killer who defies belief. (S3, ep 3)

Series exploring some of the most baffling and challenging investigations in modern law enforcement. (S8, ep 2)

Deadly Accusation: When Virginia Beach detectives were called to the scene of a bloody double homicide in May 1996, they uncovered a murder plot too strange to believe. (S7, ep 2)

Vanished in Reno: When a young university student is abducted from a friend's home in the middle of the night, the city of Reno, Nevada lives in fear of who might be next. (S6, ep 2)

Christmas Mourning: In 1988, Beverly Eller was found murdered in her home. Years went by before a piece of evidence surfaced that tied an unlikely suspect to the crime. (S5, ep 2)