What creates a serial killer? Is it possible to predict that someone will become a rapist? Do spree killers share common character traits and childhood experiences? What turns a child into a murderer? And how do they explain their crimes?

To unravel the psychological profile of the world’s most dangerous criminals, consultant forensic psychologist Kerry Daynes, examines some of the most infamous cases and goes in search of in-depth, personal interviews with convicted criminals and killers.

Kerry is not your average forensic psychologist. She’s female, she’s glamorous and she talks in accessible sound bites. She’s passionate about her subject and she’s on a mission to investigate, understand and unravel a psychological blueprint of violent crime.

Each episode of The Making of a Monster will take Kerry on a journey into the minds of violent criminals; serial killers, rapists, fantasists, paedophiles, wife beaters, women who kill, arsonists. It’s a journey with many twists and turns as she builds up a clear psychological profile.

Mark and John - The Fantasists

A teenager created an ”elaborate matrix of deceit” on the internet to persuade another boy he had fallen in love with to murder him.

The 14-year-old boy - dubbed John in our programme - created a series of fictional characters in chatrooms, one of which ordered Mark to murder him. (These are not the real names of the two boys. The court ruled that their identities should remain anonymous.)

Just before 8pm on Sunday 29th June 2003, the police took a call from 16-year-old Mark. His best friend John had been stabbed in a quiet alleyway just off the main street in the affluent suburb of Altrincham.

John was rushed to a nearby hospital critically ill with stab wounds to his chest and stomach. At first the police thought it was a brutal but straightforward mugging that had gone horribly wrong. But soon the police discovered that the stabbing had been carried out by John’s best friend Mark.

Under questioning Mark revealed he had been recruited over the internet by a spy mistress who said she was working for the British Secret Service and that the spymistress had ordered him to kill John.