Accused child-killer dumped items in the bush

After being charged with murdering his fiancee's daughter, Justin Laurens Stein asked his mother to retrieve items he dumped in the bush and was incredulous to hear police may have already uncovered them.

Stein is on trial for murder in the NSW Supreme Court over the death of schoolgirl Charlise Mutten, whose body was found in a barrel by the Blue Mountains' Colo River on January 18, 2022.

Prosecutors allege the 33-year-old shot the schoolgirl while she was visiting him and her mother, Kallista Mutten, at a property in Mount Wilson, near where her body was found.

In a series of prison phone calls played to the jury on Tuesday, Stein tells his mother, Annemie Stein, that he did not shoot the nine-year-old, which she says she believes.

Stein claimed to have witnessed Ms Mutten shoot her daughter just outside the Mount Wilson property and to have heard the girl scream, "mummy no".

In another call, Stein says he needs his mother to "retrieve some stuff in the mountains".

"You know how I borrowed certain things off my friend to take care of those drones," he says.

"I never got to take them back. I kind of dumped them in the bush. So I need you to retrieve them."

Ms Stein tells him: "I think they found them."

"What do you mean?" he replies.

"I've got a feeling that they might already have them," Ms Stein says.

Neither one identifies exactly what they are referring to, but Ms Stein says she can't talk about it over the phone.

Ms Stein was earlier interviewed at Katoomba Police Station and shown images of two .22 and .30 calibre rifles officers recovered from a remote fire trial near the Mount Wilson property.

Prosecutors allege Stein and Ms Mutten stole the weapons from a nearby property in the months before Charlise's visit.

The smaller-calibre rifle contained Stein's fingerprints and a scope which he allegedly purchased from eBay, according to prosecutors.

"They showed me photographs," Ms Stein tells her son in the call.

"Why do they keep showing me? I don't know. To ruffle my feathers?"

Stein then tells her: "They came to see me because they haven't got a murder weapon, so they haven't got anything."

While being processed into Sydney's Silverwater jail the day after Charlise's body was found, Stein allegedly told a corrections officer he was innocent and blamed Ms Mutten for the shooting.

"Her mum was on ice all week," Stein said, according to the officer.

"I heard a shot and then I heard her screaming out for me. Then I ran back and she shot her again.

"I keep having flashbacks. I'm not going down for this. I'm not going down for that b****.

"I've been trying to tell people this for days and no one would listen. Thank you for letting me vent."

The corrections officer, Stacey Sweeney, told the trial on Tuesday that "nine out of 10" inmates she met pleaded their innocence.

The trial continues.