Man affected by ‘nang’ use before Sydney murder and controlled his girlfriend with list, court told

A man who stabbed his girlfriend to death and fell from a balcony had written a disturbing list of rules for her to follow.

A man who stabbed fatally his girlfriend before he fell or jumped off a balcony at a Sydney apartment building had previously forced her to sign a ‘contract’ of rules limiting her behaviour.

Weijie ‘Jack’ He survived the fall from the Wolli Creek unit and was charged with 19-year-old student Liqun Pan’s murder when he woke from a coma seven months later.

Hundreds of empty nitrous oxide canisters were found in He’s home as police investigated the incident on June 27, 2020, the NSW Supreme Court heard on Tuesday.

He was likely suffering from psychosis bought on by his heavy addiction to ‘nangs’ at the time of Ms Pan’s murder, a court has heard.

A friend had been told the killer had consumed five boxes of the canisters, known colloquially as ‘nangs’ or ‘gas’, in the days before Ms Pan’s frenzied murder.

One medical expert described that as a ‘heroic amount’, which may have had a lingering impact on the 24-year-old’s mental state at the time.

Liqun Pan was found dead in her Wolli Creek apartment.

The 19-year-old was murdered by her partner.

Crown prosecutor Rossi Kotsis also told the court that a jealous and “controlling” He was angry at Ms Pan after discovering she had a “sugar daddy”.

“He told (a friend) he looked down on (Ms Pan) because she got paid by an older man and he didn’t want to see her again,” the court heard.

Mr Kotsis said the offender had once forced his partner into signing a contract limiting what she could do while on a trip to China, including conditions such as she could “not go to bars, drink or do anything with the opposite sex”.

Any breach of the contract would mean the “disappearance of love and that he no longer matters. And end of relationship”, Mr Kotsis told the court.

Mr Kotsis said He had told his mother in text messages about “beating up” Ms Pan when she didn’t do her share of chores around the house.

After a preliminary hearing that found him fit to stand trial, He pleaded guilty to murder in 2022 and today faced a sentence hearing.

Brought into court in a wheelchair, the court was told He suffered severe injuries in the fall as his lawyers argued the young man was significantly affected by five years of nitrous oxide abuse when he killed his partner.

Ms Pan’s father delivered an emotional statement about his beloved daughter. Picture: Adam Yip

Dr Adam Martin told the court he agreed with a psychological assessment of He that found the offender was likely “heavily intoxicated” and suffering from “transient delirium” due to the substance use.

“Nitrous oxide is known to be short acting, however it can also be associated with mental disturbance which goes beyond that five minutes half-life,” Dr Martin said.

“So you could argue the delirium (or) call it psychosis … it still comes under the rubric of being under the influence.”

Dr Martin didn’t agree that there were no other “realistic motivations” for Ms Pan’s murder, other than psychosis, saying “it’s well known that people in controlling or dysfunctional relationships can act violently”.

Another expert, Professor Macdonald Christie said the five boxes of nitrous oxide He had inhaled in the days before the murder was “an heroic amount”.

Professor Christie said such extreme consumption could have ongoing affects much like an alcohol hangover after an excessive night of drinking.

Nitrous oxide canisters are generally used to make whipped cream. Picture: Toby Zerna

A father’s grief

Ms Pan’s father spoke of his family’s devastation at her death in a witness impact statement read to the court by Mr Kotsis.

In the statement, her father said Ms Pan was the eldest child of the family and had left for Australia to seek an education that was not available in the rural village where she grew up.

“The immeasurable pain (of Ms Pan’s death) crushed everyone. We couldn’t accept it was true,” he wrote.

Ms Pan said he felt the blood “drain from my heart” when police officers told him of the “extensive and horrific injuries” his daughter had suffered.

“Those were the words any father would never want to hear,” Mr Pan said.

“Her death broke my heart. Liqun’s mother still can’t accept that our daughter was murdered.”

The father asked why the gods had been “so cruel” to his family, saying he had shielded Ms Pan’s younger siblings from the truth of her fate.

“She should have been experiencing the best time of her life, but her young life was barbarically cut short by such a heinous crime,” he said.

Mr Pan said he hoped his daughter’s killer “rots in jail”.

“He must be made to pay,” he added.

The hearing continues.