Nearly three years ago, teenager Jason Galleghan met his friends at a western Sydney train station.
A few hours later, he was left for dead after a brutal bashing, lying alone in his boxer shorts.
On Monday, Kayla Dawson, 22, and Richard Sione, 34, were found guilty in the NSW Supreme Court of the 16-year-old's murder.
Dawson lured Jason - who she suspected of stealing her Apple AirPods - to her home, where he was savagely beaten by Sione and subsequently by a group of teenagers who referred to the much older man as "uncle" or "dad".
The 16-year-old died of his injuries two days after the August 2021 assault.
"The murder of the deceased was carried out in such horrific circumstances and the role of Miss Dawson was central to it," acting Justice Robert Allan Hulme said in his decision following a judge-alone trial.
Dawson made it known to at least one of the teenagers that she believed the teenager had stolen her AirPods, and it was decided Jason would be lured to the suburb of Doonside and bashed as punishment for the suspected theft.
"Me and two of the boys are bashing someone today lmao," a text from one of the teenagers read.
Dawson, two teenagers and another adult met Jason at the local train station before inviting him back to her home, where Sione and others were waiting.
Jason was taken to a bedroom, where two witnesses said he was interrogated by Sione before he started bashing the teenager.
The 34-year-old was estimated to be in the bedroom with the victim for up to five minutes before another adult, Thomas Pakau, intervened after hearing loud banging noises.
Shortly after Sione left the room, five of the teenagers continued the beating while Dawson watched and took videos.
Mr Pakau referred to the youths as Sione's "little minions" or "little power rangers".
Sione argued, through his lawyers, that while he hit Jason, he left before others carried out a more sustained and violent assault on the teen.
But Justice Hulme found he was involved in a joint enterprise to harm the victim and was therefore also culpable for the 16-year-old's murder.
Reading a victim impact statement, Jason's mother Rachel Galleghan said every day had been a struggle with agony and heartache since losing her son.
"It gets harder and harder knowing I must spend the rest of my life without my precious son, who would have been 19 years old now," she told the court.
"Jason was the love of my life and living without him has shattered me."
Ms Galleghan has described Jason as gentle, fun and playful, as well as being "an amazing brother to his younger sisters".
Justice Hulme rejected Dawson's application to have her charge reduced to manslaughter due to a substantial cognitive impairment, saying her decision to film and transmit video of the incident worked against that claim.
"I just can't stop laughing, I'm sending it to Johnno," she said at the time of the assault.
Several other teenagers charged over the fatal beating remain before the courts.
Dawson and Sione will return to court for sentencing on July 8.
