Accused murderer Justin Stein told the mother of then-missing schoolgirl Charlise Mutten not to call police or the girl's kidnappers would kill her, a court has heard.
The body of nine-year-old Charlise was found by police in a barrel by the Blue Mountains' Colo River on January 18, 2022 with gunshot wounds to her face and back.
Stein, 33, has pleaded not guilty to the murder as he stands trial in the NSW Supreme Court.
He now claims it was Charlise's mother, Kallista Mutten, who shot the girl.
Appearing in the witness box for the first time on Monday, Ms Mutten said Stein told her that former associates from his criminal past could have taken the girl and he instructed her not to call police.
On January 13, while phone data tracked Stein allegedly travelling to three boat ramps across Sydney and eventually the exact location where Charlise's body was found, Ms Mutten believed he was "going to war" to find her daughter, the court heard.
"Justin said he's gonna go to war and go to places that he might think that she might be and go look for her and get her," Ms Mutten said.
Later, she said, "Justin had called me and said that he 'badly hurt' the man that was in the house (where) he thought Charlise was ... and stabbed him".
When he returned in the early hours of the next day, Ms Mutten says Stein told her, "It's not them, you can call the police in the morning".
Ms Mutten told the court that on January 12 - about when prosecutors allege Stein committed the murder - he claimed to have left an unwell Charlise in the care of a woman who was spending the day valuing antique items at the Blue Mountains property where they were staying.
Thinking her daughter was in the care of that woman, Ms Mutten said she travelled with Stein to Sydney where they bought and both injected methamphetamine.
The next day, when there was no sign of the auctioneer or her daughter, Ms Mutten said she and Stein argued and she left the property in his car, prompting him to report the vehicle as stolen to police.
Ms Mutten said she returned to the property between 30 minutes and an hour later and tried to hide from Stein in a shed, before he located and attacked her.
"He found me and grabbed me and pushed me to the ground and started kicking into me and hitting me and grabbing my shoulders and my clothes and shaking me," an emotional Ms Mutten told the court.
"I remember just yelling ... 'just stop, because I just want my daughter'."
Ms Mutten said she was left with bruising to her arms and scrape marks across her chest.
Stein later said the "auctioneer" he left Charlise with might not have been who he thought she was and the girl's disappearance could be linked to "ex-affiliations" from his criminal past, Ms Mutten told the court.
"I said, 'we should go to police'," she said through tears.
"He said, 'no, because if you ring the police they will kill her'."
Stein said he would look for the girl himself, leaving the property towing a boat with his ute, Ms Mutten said.
He explained he was taking the boat because "if s*** goes down and people get hurt or anything happens he's gonna probably try to get rid of some evidence", she added.
Ms Mutten earlier told the court at the time of her daughter's disappearance she had hopes of marrying Stein.
The schoolgirl, who lived with her grandparents on the Gold Coast, was visiting her mother and Stein over Christmas at the time of her death.
The group spent their time during the visit between the Mount Wilson property and a caravan at the Riviera Ski Park, about a 90-minute drive away.
During the visit, Ms Mutten said Charlise had referred to Stein as "dad" or "daddy".
Ms Mutten claims she saw her daughter for the last time on January 11 when the nine-year-old travelled alone to spend the night with Stein at Mount Wilson while she remained at the caravan park.
The trial continues.
