Vincent Tabak watched porn films where women were held around the neck – before he strangled Jo Yeates.
Forensic experts seized four of the 33-year-old Dutchman’s computers after he was arrested over the killing of pretty Jo on January 20 this year.
They found evidence of Tabak watching sex and submission porn videos where women – some bound and gagged – were held by the neck during intercourse.
A still image of two unclothed woman tied up in the boot of a car was also found on his hard-drive, along with a pictures of a girl matching Jo’s description.
The girl, wearing similar clothes to Jo on the night she died, had her top raised in the photograph – mirroring her final position when she was dumped in Longwood Lane.
The material was withheld from the jury after Judge His Honour Mr Justice Richard Field deemed that they did not inspire the attack on Jo, but ruled it admissable for background purposes.
Nigel Lickley QC, prosecuting, tried to argue that the material gave Tabak motive for the killing.
He told the court: ”The material was found on the defendant’s laptop at home and also in relation to two hard drives – one found at home and one found at work.
”They concern the defendant’s interest in porn. But in particular porn depicting violence towards women with their tops raised.
”There are also violent images of women being held by the neck, then being sexually abused by men.
”We submit that these images have a real significance and explain why the defendant held Joanna Yeates by the neck and killed her.
”We submit that it is the case he developed a sexual pleasure from it and that is because he viewed this material.
”There is sexual activity between a man and a woman – often bound and gagged.
”They are high quality titles of sex and submission. It is a fact that the women are held by the throat often when gagged – as a means of control.
”There is a scene where the women are degraded and subjected to sexual activity at the hands of a man who is in control of them.
”The defendant liked these films because he watched more than one – sometimes more than once.
”It is suggested that he derived sexual pleasure from watching them.”
Computer analysis of his hard-drives also found three images of a blonde, petite girl – wearing a pink top and blue jeans – with her top up exposing her breasts.
Prosecutors alleged they were similar to the final position Jo’s body was found in.
Another image showed two unclothed women bound and gagged in the boot of a car.
Mr Lickley said: ”In short these images, we submit, hold resonance with the final position of the deceased.
”There is a similarity in the two females height, hair colour and the clothing.
”Miss Yeates was wearing a short pink top and jeans. Miss Yeates was found wearing her jeans in tact but her t-shirt she was wearing had been lifted up above her bra.
”Her bra had been moved to leave her right breast exposed. The defendant’s DNA was found on her chest, breasts and arms.”
Evidence was also raised that showed Tabak accessed an internet portal for porn, t8premium.com, on the morning of December 17 – the day he killed Jo.
He also watched domination porn videos on January 7, while searching for information on the Jo Yeates case.
Examination of his computer showed that at 7.37am he was looking at that material to do with the murder investigation.
Less than two minutes later he started looking at porn website Redtube.com and saw a number of different films – some involving women held by the throat.
In one a female actress tells another participant to choke her.
Tabak then received a text from his girlfriend before continuing to watch the porn.
Mr Lickley told the court: ”The images are relevant. They are relevant because they help to illuminate aspects of the case which remain less clear.
”Why strangle her? Why take this woman by the throat? Was it in the context of these films?
”Has he moved from observer to participator?
”If it was domination and sexual motivation that may give some insight into what he intended.
”It might shed light on the need to hold a woman for long enough and the need to squeeze hard enough to take her life.
”If there was a sexual motivation behind the attack of Miss Yeates, then this material indicates the defendant is sexually aroused by this material.”
William Clegg QC, defending Tabak, insisted the material was not illegal and would not help the jury come to a conclusion about his client’s guilty mind.
He said there was no evidence that the Dutchman had watched the scenes in the porn films where the women were held around the neck.
Mr Clegg also said that the three women of a similar appearance to Jo were among 56 thumbnail pictures on his laptop.
Judge His Honour Mr Justice Field dismissed the application to have the material introduced to the trial and rejected prosecutions claim that it showed an intent to kill.
He said: ”These films show actors, acting out roles. None of the women suffer GBH. None of the women are killed.
”These are not snuff movies. The women did not die.”