Filming himself torturing and killing a young Indonesian woman, British investment banker Rurik Jutting veered between boasting, remorse and describing the pleasure he derived from sexually brutalizing the first of two victims.
Footage taken from four hours of recordings on Jutting's mobile phone formed the core of the prosecution opening on the second day of a murder trial in Hong Kong that has grabbed global attention.
The 31-year-old Cambridge University graduate has admitted killing Sumarti Ningsih, a 23-year-old single mother, and another Indonesian woman, Seneng Mujiasih, in his luxury high-rise apartment two years ago.
But he has pleaded not guilty to murder on grounds of “diminished responsibility”, while pleading guilty to the lesser crime of manslaughter.
The four women and five men on the jury clenched their jaws and, at times, diverted their eyes as they endured an opening 20-minute segment of the torture of Ningsih. Tears welled up in the eyes of one middle aged male juror.
Chilling details emerge:
Appearing topless, overweight and unshaven, Jutting appeared on camera, at times showing Ningsih's body, and spoke with chilling calm in a series of monologues that he described as "narcissistic ramblings".
While the video was not shown to the public in the courtroom, journalists covering the trial could hear the audio.
"I just killed someone, first person I ever killed, I cut her throat in the bathroom ... to be precise I cut her throat while she was bending over licking dirty toilet bowl," he said.
Jutting, who had held a high flying job at Bank of America in Hong Kong before his arrest, at one point filmed himself taking cocaine as he explained how he tortured Ningsih.
"I treated her as a non person, a sex object. And that turned me on."
Bespectacled and wearing pale blue shirt, Jutting was flanked by three policemen as he watched what he had done on a video recording a judge said had been found on his iPhone.
Jutting, who had attended Winchester College, one of Britain's most prestigious private schools, shut his eyes, sometimes covering his face with his hand rather than look at the screen in front of him.
Jutting used a belt, sex toys, a pair of pliers and his fists to torture Ningsih over three days before eventually slitting her throat with a serrated-edged knife, according to the prosecution.
On the recording, Jutting spoke in a relaxed, soft voice as he taunted, bullied and mutilated Ningsih, a single mother who had been visiting Hong Kong on a tourist visa.
"Its better than being beaten isn't it? Do not cry, take it like a good girl," Jutting said as he described how he was going to put his fist into her.
Jutting called his victim 'Alice' as he tormented her.
While threatening to cut off her nipples he calmly said: "This doesn't really hurt does it? You deserve some water don't you? Just one more before some water."
After that video, others showing Jutting and Ningsih's mutilated, naked body were screened in an open court room.
In one, Jutting spoke of a "fantasy" to kidnap three teenaged girls from Wycombe Abbey, a girls' boarding school in High Wycombe, a town northwest of London.
In one scene he urinated into a beer glass as he expressed fears of being jailed in Hong Kong, planning to return to Britain to co-operate with authorities.
In another, he played the song Disturbia by pop artist Rihanna as he lays out freshly purchased hardware store "goodies" he plots to use on another victim - a hammer, and nails, pins and sandpaper.
Prior to the jury selection on Monday, Deputy High Court Judge Michael Stuart-Moore warned potential jurors that if they were unable to cope with viewing extreme violence they should excuse themselves.
The defense and prosecution were largely in agreement over the physical evidence, Stuart-Moore had advised the jurors on the first day of the trial.
He told them that the outcome could rest on psychiatric and psychological testimony to determine whether it was a case of murder or manslaughter. Murder carries a mandatory life sentence, while manslaughter carries a maximum of life though a shorter sentence can be set.