Derek Barrett has been sentenced to a maximum of 46 years behind bars for the "sadistic" stabbing murder of his niece in April 2016.
University student Mengmei Leng - also known as Michelle - was tied up and killed by Barrett, her aunt's husband, at the home they all shared at Campsie in Sydney's west.
Two days later, her naked body was driven more than 100 kilometres away and thrown off a cliff into a blowhole at Snapper Point on the Central Coast. It was spotted by tourists hours later.
On Friday, Justice Helen Wilson sentenced Barrett, 29, to at least 34 years and six months in prison for his crime, with a maximum of 46 years. He will be eligible for parole in 2050.
Barrett pleaded guilty in August to murdering and kidnapping his 25-year-old niece, as well as sneaking into her room twice while she slept and taking videos while he touched himself.
He also admitted to taking 19 explicit photos of Ms Leng shortly before she died.
Barrett claimed this week he could not remember the 48-hour period during which he killed Ms Leng, including cleaning the crime scene and dumping her body, because he was high on ice and synthetic cannabis.
He said his only memories were of an argument, seeing blood in the bathroom sink, and his niece's terrified face shouting at him.
However, Justice Wilson said she did not believe Barrett was telling the truth about his memory loss, and did not believe he was genuinely sorry for what he had done.
"Had the offender been genuinely remorseful ... he would have given an honest account of what he did, and why. I do not believe the offender has done that," Justice Wilson said.
"I have concluded the offender can give an account of these events. He has chosen not to."
Justice Wilson said Barrett had "the air of someone playing a part and saying what he thought he should say" when he gave evidence about his "depraved and sadistic" crime.
Though he appeared to cry in the witness box, "his distress seemed somewhat contrived".
The Supreme Court heard Ms Leng probably died on the morning of April 22, because photographs on Barrett's phone showed her tied up on a bed at 8.37am, looking at the camera with terror.
Later that day, when Ms Leng's cousin arrived home, Barrett remained in the bathroom for at least three hours with the shower running the entire time.
"With the amount of blood I saw in the sink, it could have been [me] cleaning," Barrett said.
On the evening of April 24, when his wife arrived home from a work trip to Wollongong, she noticed the house was "exceptionally clean", with duct tape, towels and a suitcase missing.
Records showed Barrett did not leave the Campsie apartment from April 22 to the early hours of April 24, except to take multiple trips to the apartment's basement, where residents dispose of garbage.
Barrett showed no emotion when he was sentenced, but shook his head when Justice Wilson said the only motivation for taking photos of the victim was his "aberrant sexual pleasure".
Speaking outside court, Detective Chief Inspector Gary Jubelin from the NSW Police Homicide Squad said Ms Leng's murder was "horrendous" and "senseless".
"From an investigative point of view it's satisfying that we've got justice, but there's no joy in a matter like this," he said.
"It's just an extremely sad case. It's a horrendous matter, and the family are traumatised by what's gone on."
