A man who admitted murdering and dismembering three women and who described himself as the "crossbow cannibal" was today told he would spend the rest of his life in prison.

Stephen Griffiths, 40, pleaded guilty at Leeds crown court to the murders of Susan Rushworth, 43, Shelley Armitage, 31, and 36-year-old Suzanne Blamires. All three women had been working as prostitutes.

Sentencing him to life in prison, Mr Justice Openshaw said: "The circumstances of these murders are so wicked and monstrous they leave me in no doubt the defendant should be kept in prison for the rest of his life."

He said Griffiths' guilty pleas were entered without any remorse at all. "He never said he regretted his actions or said in even the most perfunctory way he was sorry," the judge said.

Griffiths was studying for a PhD in criminology at Bradford University. His thesis was entitled Homicide in an Industrial City - Violence in Bradford 1847-1899.

Prosecutor Robert Smith QC, told the court that the case came to light this May when Peter Gee, the caretaker at the Holmfield Court flats in Bradford where Griffiths lived, examined CCTV footage from the previous weekend.

Gee had been warned not to approach Griffiths if he was alone in the flat as he was potentially violent and because of his unstable behaviour. A number of sex workers had been seen entering Griffiths' flat, number 33.

"He saw an image of someone on the third floor dragging a person into flat 33," Smith said. The caretaker went back through the footage and saw Griffiths enter his flat with a woman at 2.29am on 22 May. Shortly afterwards, she was seen running out of the flat with Griffiths following. She was thrown or fell to the floor. Griffiths had a crossbow in his hand, which he pointed at the woman's body.

"He fired it and pulled her into the flat by one of her legs." He later emerged and pointed the crossbow at the CCTV camera.

Two vice squad officers who were called to watch the CCTV recognised Griffiths: he had been brought to their attention at a briefing held in late 2009.

It emerged that the woman was his final victim, Blamires. A neighbour, who said the walls were paper-thin, said they heard the sound of banging and rising voices that continued for half an hour. The neighbour heard a woman scream in pain and shout: "Get off me, you ignorant bastard." There was a heavy thump and silence.

A pathologist discovered a bolt and part of a knife embedded in her skull. A member of the public found a heavy bag containing her head submerged in the river Aire at Shipley. In total, there were 81 body parts belonging to Blamires found in the river. Her nose and ears had been removed. A foot had been sawn off and found in a rucksack.

Within an hour of killing Blamires, Griffiths approached another woman who was working as a prostitute, known as R, and asked her for business. He offered her £80 for an hour and said he could pay for the whole night. The prosecution said that had R entered the flat she would have become his fourth victim.

When police arrested Griffiths in May, Griffiths replied: "I am Osama bin Laden."

During the interview, he told police: "I've killed a lot more than Suzanne Blamires."

Smith added: "He said he'd eaten part of her body. He told police he'd eaten Rushworth's thighs and disposed of her body."

The court heard that he told detectives that cuts to his hands were because of the "slicing and dicing". Part of his hair was singed.

"I or part of me was responsible for the murders of Susan Rushworth, Shelley Armitage and this Suzanne Blamires whose name I thought was Amber," Smith said Griffiths had told police.

Griffiths admitted the murders and that he butchered, dismembered, eating parts of all three of them, the prosecution said.

As horrific details of the murders were read out in court, Rushworth's daughter Kirsty stormed out, shouting at Griffiths: "You fucking cunt." He briefly glanced at her, before bowing his head. Rushworth's remains have never been found, causing considerable anguish to her family, the court heard.

Smith said Griffiths placed some of Rushworth's body on an old sofa outside his flat and set fire to it. The fire brigade were called.

The court heard of Griffiths' long history of psychiatric treatment. At 17, he was diagnosed with a personality disorder and was assessed in the high-security Rampton hospital in Nottinghamshire, where it was concluded that his condition would not respond to treatment.

In October 1991, he told a psychiatrist he was strongly attracted to the idea of killing someone. Later, he told a probation officer of his fantasies and preoccupation with multiple killings. "He had an idolisation involving Peter Sutcliffe," Smith told the court.

"Sometimes you kill someone to kill yourself," Griffiths reportedly also said. "It is like deep issues inside me." Griffiths had admitted being misanthropic and didn't have much time for the human race.

The judge read out a psychiatrist report and said it was quite clear that Griffiths lured these women to his flat and killed them.

"Quite why he did so is to some extent obscure," the judge said, adding that a psychiatrist, Prof Nigel Eastman, had concluded Griffiths had enjoyed exerting power over others. Griffiths had taken digital images of one of his victim's naked body and uploaded it on his computer.

Eastman had concluded that although little research has been carried out on criminal cannibalism, the consensus was that it represents "the ultimate power".

Referring to the professor's report, the judge added: "It is one thing to terrorise and kill but to dismember and eat parts of the victims takes it to another level of the exertion of power and sexual gratification."

Smith said that Griffiths admitted killing Blamires in his flat and dismembering her by hand. He had used power tools on the other victims. Detectives later found 30 knives in the flat. "It was just a slaughterhouse in the bathroom," Griffiths reportedly told detectives.

Police said his flat was full of books, journals and documents all related to homicide. Two bloodstained crossbows were on an armchair.

Detectives found a video on his camera showing Armitage lying dead in his bath. Another unidentified victim was lying on the living room floor bound with green twine.

The prosecution said Griffiths had convictions for violence that demonstrated his unstable personality. In 1989, he had slashed a store manager across the face after he was caught shoplifting.

The senior investigating officer in the case, Detective Superintendent Sukhbir Singh, said there was no direct evidence to link him to the disappearance of any other sex workers. Asked if he thought he killed anyone else, he said: "No I don't."

Singh added: "He is a heartless and controlling man who took advantage of vulnerable women. What he did can never be forgotten by the families of his victims."