Killer Britain

As a teen Mark Martin had an unusual ambition. He wanted to be a serial killer, just like the men he admired and loved to read about: The Krays, Donald Neilson, Ian Brady. And Martin had his eye on the perfect victims: the vulnerable homeless people who frequented the lonelier parts of Nottingham.

Glyn Dix met Hazel while he was serving a life term for a brutal rape and murder. After convincing her he had been framed, the couple fell for one another. But five years after his release from prison, Glyn finally showed Hazel his true colours.

Stephen Port was a predator who selected his victims through online dating apps; he took the lives of four young men in East London in just a few short months. The sisters of one victim set out to prove their brother hadn't died of an overdose as police believed - and in the process they unmasked a serial killer.

The world behind James Fairweather's bedroom door was a dark one - he fixated on violent pornography, the lives of serial killers, games in which he learned how to kill. It was a training school for his real-life ambition: to gain the adrenaline kick and the notoriety of becoming a serial killer.

At the age of 16 Sana Muhammad had an arranged marriage to Ramanodge Unmathallegadoo, a man almost twice her age. When the family moved to the UK she managed to escape the unhappy relationship. She found new love, but Ramanodge decided she would never get to enjoy her new life.