A Sydney man who bound and gagged his niece before stabbing her to death, and dumping her body in a blowhole has been jailed for 46 years.
Derek Barrett, 29, previously pleaded guilty to murdering Chinese university student Mengmei Leng, whose naked body was found floating in the blowhole at Snapper Point on the NSW Central Coast in April 2016.
The former IT worker also admitted filming Ms Leng for his sexual gratification.
"This was a despicable crime of extreme brutality and great wickedness," Justice Helen Wilson said at the NSW Supreme Court on Friday when sentencing Barrett to 46 years in jail with a non-parole period of 34 years and six months.
"It was a depraved and sadistic act committed by a man in a position of trust to Ms Leng, and in a place that should have been one of safety and refuge for her."
Ms Leng, 25, had lived with Barrett, her aunt and her cousin in the southwest Sydney suburb of Campsie since arriving in Australia to study five years before her murder.
When his wife was out of town on April 22 last year, Barrett gagged and bound Ms Leng to her bed. He then took 19 photos of her naked body.
Justice Wilson said Ms Leng must have been in great pain and fear as she lay "humiliatingly exposed".
In one photo the student "appears terrified", she said.
At some point over the next two days, Barrett stabbed Ms Leng to death.
On the morning of April 24, he drove her body, wrapped in plastic, to Snapper Point and dumped it over a cliff into the blowhole.
Justice Wilson rejected Barrett's claim he doesn't remember the events of that weekend because he'd taken the drug ice and synthetic marijuana.
"I have concluded the offender can give an account of these events, he has chosen not to," she said.
The judge also found it difficult to accept Barrett was genuinely remorseful.
"He had the air in the witness box of someone playing the part," she said.
"His distress seemed somewhat contrived."
