Mujiasih met with a similarly cruel end days later, tortured and eventually killed as Ningseh's remains rotted inside a suitcase on Jutting's balcony.
Now the Cambridge-educated, 32-year-old and his legal team are trying to have his convictions overturned, claiming the trial judge had misdirected the jury on his "abnormal mind".
Jutting had pleaded guilty to manslaughter after admitting killing the women, both Indonesian, in his Wan Chai flat in November 2014 but denied murder on the grounds of "diminished responsibility".
His defence had argued that cocaine and alcohol abuse, as well as personality disorders of sexual sadism and narcissism, had impaired his ability to control his behaviour.
The prosecution rejected this, stating Jutting was able to form judgments and exercise self-control before and after the killings, filming his torture of Ningsih on his mobile phone as well as hours of footage in which he discussed the murders, bingeing on cocaine and his graphic sexual fantasies.
During the hearing in Hong Kong's Court of Appeal last week, Jutting's lawyers said Deputy High Court Judge Michael Stuart-Moore, who presided over last year's trial, had misdirected the jury.
Defence lawyer Gerard McCoy argued that the judge had narrowed down the scope of the defence case by conflating an abnormality of mind with a psychiatric disorder.
Jutting's defence is that while a disorder can cause an abnormal mind, his mental state can be abnormal without a disorder.
Mr McCoy said Jutting showed severe traits of psychiatric disorders far beyond the normal range and was therefore not in control of his actions.
"Abnormality of mind is absolutely not confined to a disorder or a disease. Here the judge locks it down, reinforcing to the jury it is disorder," he said.
In his closing remarks at Jutting's 2016 trial, Deputy High Court Judge Michael Stuart-Moore described the case as one of the most horrifying in Hong Kong's history.
One of the most compelling and graphic accounts of the trial was penned by Time journalist Nash Jenkins.
"In these days of sex tapes, amateur porn and online sex, the footage seems unremarkable at first — a young man instructing a younger woman to use a sex toy as he films the scene on his iPhone," he wrote in his October, 2016 piece.
"But, in the next sequence, it degenerates into grotesque violence. As electronic dance music hits play in the background, the woman whimpers while the man hits her, violates her sexually and threatens to mutilate her.
"These, and much worse, were the scenes to which a jury in Hong Kong was subjected on the second day of the trial ..."
"Because of the macabre nature of the footage, the trial was temporarily moved to a smaller courtroom where only the jury could observe the clips on personal video screens," Jenkins wrote.
"The accompanying audio, however, was played to the court. Much of it consists of Jutting instructing a sobbing Sumarti to prepare herself for the coming abuse; several minutes are simply the sound of Jutting's various weapons striking her body.
"After he finally killed Sumarti — he slit her throat — he turns the iPhone camera on himself, recording hours of nearly incoherent personal narration that, on Tuesday, were presented to the jury, the public and the press. In the videos, a nude and sweaty Jutting confesses to his first murder.
"'I cut her throat while she was voluntarily bending down on her hands and knees licking the rim of a dirty toilet bowl,' he says in the video. 'She did it voluntarily because she knew if she didn't I would beat her very badly.'"
Jutting was arrested in the early hours of November 1, 2014 after he called police to the luxury rented flat in the heart of Hong Kong's seedy nightclub district of Wan Chai.
"There, officers found the decaying and mutilated body of the woman in the video, 23-year-old Sumarti Ningsih, shoved into a suitcase on his balcony," Jenkins wrote.
"On the living room floor lay the body of a second woman, 28-year-old Seneng Mujiasih. The apartment was strewn with cans of Red Bull and 26 small plastic bags that had each held a gram of cocaine."
Hong Kong Court of Appeal judges Michael Lunn, Andrew Macrae and Kevin Zervos are to return judgment on the appeal which may include granting Jutting the opportunity for a new trial.
Lawyers for Jutting, who appears to have slimmed down dramatically over the past year, told reporters outside that he expected a decision to be handed down within the next five weeks.
Meanwhile, the families of both victims have filed lawsuits against Jutting in a bid to claim compensation for their deaths.
