An enraged Xiaozheng Lin strangled a woman in his apartment after she asked for more money while doing sex work.
“I put her under my control and force,” he told police after his arrest.
But his killing spree was not over yet.
About 24 hours later, the 22-year-old killed a second sex worker in her home.
He left the two women, Yuqi Luo, 31, and Hyun Sook Jeon, 51, for dead after attacking them in December 2022 and stealing cash and personal belongings, including designer handbags.
Lin, now 24, was due to face a murder trial for the two deaths in August.
However, a month before the trial he offered to plead guilty to two counts of murder, which prosecutors accepted.
Details of the case have not been reported since early 2023 due to a court gag order, which has since been lifted.
Lin remained silent and kept his head down as he faced the Supreme Court in Melbourne for a pre-sentence hearing on Monday.
Massacre: Xiaozheng Lin strangled a woman in her apartment and then killed another sex worker the next day
He visited a brothel on Boxing Day 2022, before calling a friend to take him to see Ms Luo, a Chinese national who operated a sex work business from her Melbourne apartment.
Lin told his friend that he planned to rob Ms. Luo, as he had recently lost money playing TAB.
He was dropped off near his apartment after midnight on December 26, when he took a shower and had sex with Ms. Luo.
Later, he asked her for oral sex but she refused to do it at no additional cost.
Lin became angry at Mrs. Luo and pressed her against the bed, but she fought back and bit Lin’s hand.
He hit Ms. Luo and strangled her, and then told police he was angry about her request for an additional $100 payment.
Lin left her for dead and stole $7,000 in cash, her phone and several designer handbags.
“She was gasping for air and I thought, ‘Okay, I had a robbery today and I didn’t kill her,'” he later told police.
A friend of Ms Luo called a locksmith and found her body, before calling emergency services.
The 31-year-old woman’s father, Luo Bo, said her death had been a “big blow to my heart”.
“It is extremely difficult to accept the cruel reality that my daughter has been murdered,” he said in a statement read to the court.
Less than 24 hours after attacking Ms Luo, Lin went to see another sex worker, Ms Jeon, a South Korean national, who lived in an apartment in Docklands.
Lin pleaded guilty to two counts of involuntary manslaughter.
After having sex, he fatally assaulted her and stole her laptop, bank cards, phone and building keys.
When Ms. Jeon’s body was found, it was too decomposed to identify the cause of her death.
Lin told her lawyer, Paul Smallwood, that Jeon was “assaulted in circumstances where she was seriously shaken”, the court was told.
Smallwood accepted his client faced a long prison sentence and would be deported back to China.
Prosecutor Kristie Churchill said Lin’s crime was “subjectively serious.”
“You have caused the death of two vulnerable women in their own homes, a place they had a right to feel and be safe, within 24 hours of each other,” he told the court.
“He robbed them, he left them in positions without regard for their safety or dignity.”
Lin, who has been in custody since his arrest on December 29, 2022, will be sentenced at a later date.