Britain's most dangerous prisoner, Robert Maudsley, is kept locked up in a glass cell underneath Wakefield jail
He's been dubbed Britain's real 'Hannibal the Cannibal' and has spent more than 40 years in solitary confinement.
Robert Maudsley, now 67, spends his days locked away in a special underground cell under Wakefield Prison and is one of the country's longest-serving prisoners.
He killed four men, three of them fellow prison inmates, and has been the centre of a TV documentary, which aired last year.
Maudsley, was put under the microscope for a new series of Making a Monster on the Crime and Investigation channel.
It tells the story of how he 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.
Allowed no contact with the general population of HMP Wakefield, he spends 23 out of 24 hours in solitary confinement.
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 ramage, 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 resemlance to Hannibal Lecter's in the film Silence of the Lambs.
The documentary tells Maudley's story as more tragic than evil. He commited horrific acts soley against sex offenders and other criminals.
During his murder trial in 1979, the court was told that during his violent rages, Maudsley believed that his victims were his parents.
The killings, according to his lawyers, were the result of pent-up aggression from a childhood of virtually constant abuse.
Maudsley 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."
He was convicted of both murders and sentenced to life behind bars at Wakefield. However this was not when he was given the full life term. It was the Home Secretary Michael Howard who later decided Maudsley should never be released.