Robert Maudsley, who has been dubbed the most dangerous prisoner in the UK, was one of the killers put under the microscope for the Making a Monster series on the Crime and Investigation channel.
It told the story of how Maudsley came to be locked away in solitary confinement as one of the longest serving prisoners in British history and how he only became branded a serial killer whilst behind bars.
It was the mid-1990s when psychiatrist Dr Bob Johnson was on a visit to Wakefield jail he noticed the prisoner who was referred to only as a number.
Dr Johnson said he thought it his duty as a doctor to find out why Maudsley became a serial killer and only now, 20 years on, he tells of their meetings for the first time.
Maudsley was one of 12 children born in Liverpool in 1953. He and some of his siblings spend the earliest part of their childhood in an orphanage before returning to their parents - which is when the abuse allegedly began.
He himself said: "All I remember of my childhood is the beatings. Once I was locked in a room for six months and my father only opened the door to come in to beat me, four or six times a day."
He was removed from the family home and put into foster care, later running away to London.
It was there he turned to drugs and became a rent boy to get by. He tried to take his own life a number of times, telling a psychiatrist that he felt a 'murderous rage' towards his parents.
It was in 1974 when a man who picked him up for sex began boasting about abusing children.
Maudsley strangled him there and then and was sentenced to life for the crime.
In 1977, while being held and treated at Broadmoor Hospital, he and another imate conspired to hold another prisoner, a convicted paedophile, hostage.
The incident has since gone down as one of the most infamous of all time. The pair tortured him for nine hours before killing him, cracking his head open.
There were media reports at the time that Maudsley had actually eaten part of the man's brain - but these were later disproved - but his new name had stuck. The real life 'Hannibal Lector'.
It wasn't long after that Maudsley was transferred to Wakefield prison - where he struck again, murdering two inmates on the same day, the body of one he hid under his bed.
It's said that he killed the second man and casually told a prison officer that the next roll call would be 'two short.'
After his latest frenzied rampage, he was considered too dangerous to be an ordinary prisoner, so a glass fronted cell was made for him in the cellar of Wakefield prison.
It's said that the cell bears a resemblance to Hannibal Lecter's in the film Silence of the Lambs.
The documentary, which aired last month, tells Maudley's story as more tragic than evil. He committed horrific acts solely against sex offenders and other criminals.
He once said: "'When I kill, I think I have my parents in mind. If I had killed my parents in 1970, none of these people need have died. If I had killed them, then I would be walking around as a free man without a care in the world."