Revealing, like never before, what it is like to be a police officer working on the most incredible and inconceivable murder cases in criminal history. A look into murder cases from the first 999 call, the investigation and then the guilty verdict.
51 Days of Fear - Howell Donaldson III: The Tampa area of Seminole Heights is gripped by terror after shootings claim the lives of four innocent victims. (S4, ep 1)
Tears of a Clown - Gordon Wardell: After Gordon Wardell makes an emotional appeal to find his wife's killers, police soon realise they must look closer to home. (S4, ep 2)
Opportunity For Riches - Steven Sidebottom: Initially deemed accidental, handyman Brian McKandie's death was soon considered murder due to his severe injuries. (S4, ep 3)
The Highway Hunter - Adam Leroy Lane: When police find the body of Monica Massaro in her home with 17 stab wounds, they're led to serial killer Adam Leroy Lane. (S4, ep 4)
Killer Women - Larene Austin - Fatal Attraction: When Lanell Barsock is found dead, evidence points to her boyfriend - before detectives focus on best friend, Larene Austin. (S4, ep 5)
The Widower - Malcolm Webster: 17 years after his wife died in a car accident, Malcolm Webster became the focus of Scotland's longest ever criminal trial. (S4, ep 6)
Letter From the Grave - Mark Jensen: When Julie Jensen is found dead, police suspect her husband Mark of murder - despite the seemingly happy family life. (S4, ep 7)
Killer Women - Kaitlin Armstrong - Malicious Intent: When elite racer Anna Wilson was shot and killed, police launched a manhunt to Costa Rica in search of Kaitlin Armstrong. (S4, ep 8)
Six days after Matthew Manwaring and his daughter Alison vanish, police uncover a grisly scene at Benjamin Laing's home. (S4, ep 9)
When young kickboxing champion Niall Dorr was beaten to death in Dundalk, CCTV helped detectives convict his killer. (S4, ep 10)