A 34-year-old man charged with the murder of 16-year-old Jason Galleghan allegedly began the fatal assault before telling a group of teens to "finish him off," a court has been told.
Richard Sione, 34, and Kayla Dawson, 22, are facing a joint murder trial after Jason was bashed to death by a group of largely teenagers at a western Sydney property in August 2021.
Parts of the chilling assault were filmed and several still images were shown at the start of a Supreme Court trial in Sydney on Monday.
One of the images showed an already battered Jason being kicked in the face, and in another, the terrified teen is seen in the corner of a bedroom wearing nothing but his underpants.
Jason's mother was present at the trial and left the courtroom while the images were shown.
Both Dawson and Sione pleaded not guilty to the charge of murder.
Sione also pleaded not guilty to an alternative charge of detaining Jason without consent, for the "psychological satisfaction of assaulting and humiliating" him.
At the time of the bashing, several younger members of the group referred to Sione as "dad", the judge-alone trial was told.
One of the teens, who later pleaded guilty to Jason's murder, appeared as a witness in the trial on Monday and told the court Sione was "like a father figure".
The now 17-year-old told the court on the morning of the bashing, he and several others were at Dawson's house, "kicking back, smoking cones".
The court heard an "upset and crying" Dawson told the group Jason had stolen her AirPods to which Sione replied "bring him over and we'll talk to him".
When Jason arrived at the home, Sione allegedly told him to go to the bedroom and began assaulting him.
Sione allegedly told Jason "don't f*** with my family", grabbing him by the hair and punching him repeatedly in the face.
DNA evidence from Sione's shoe suggests he also "kicked and stomped" on Jason the court was told.
Crown prosecutor Philip Hogan told the court the assault by Sione allegedly lasted about 10 minutes before he left the property.
Evidence will be given in the trial that Sione told those still present "youse (sic) finish him off," the court was told.
After Sione left the property it is alleged Dawson encouraged the assault to continue.
Dawson initially told police "two black guys" had chased Jason inside the house and assaulted him.
"It's common ground that account was a lie," Mr Hogan said.
Dawson later admitted she had told Jason to come to her place for the purposes of being "bashed".
"I set him up. I told him to come to my place," Ms Dawson told police.
The trial continues on Tuesday.
