'You've got the wrong guy, you'll see': What Daniel Holdom told police

Then, several days later in October, 2015, Holdom, who earned the nickname "Shrek" in his former ACT neighbourhood, asked detectives to return.

Holdom had "examined his conscience", he allegedly claimed, and wanted to tell police who really was responsible.

The accused double killer then suggested a former friend had a hand in the disappearance of Karlie Pearce-Stevenson and toddler Khandalyce in 2008.

Holdom offered to go "crown witness", court documents reveal.

However, by this stage, homicide detectives had traced Holdom's mobile phone activity to the remote NSW forest where Ms Pearce-Stevenson was allegedly stomped on, killed and dumped in December, 2008.

The alleged web of lies and admissions that threaten to land Holdom with a life-long jail sentence for killing a mother and child can now be revealed.

It comes after details of the 42-year-old's claims were outlined in prosecution documents tendered in Sydney's Central Local Court this week.

Ms Pearce-Stevenson's skeleton was found in the Belanglo State Forest in August, 2010, two years after police allege she was killed.

Holdom is accused of murdering the young mother and taking photos of her discarded body.

He then allegedly killed the 20-year-old's daughter Khandalyce, stuffed her body in a suitcase and dumped it on the roadside in South Australia days later.

A breakthrough led to both cases being linked in early October, 2015 and the mother and daughter's remains finally being identified.

It was only a matter of days before police were led to Holdom, who lived in Canberra's northern suburbs with Ms Pearce-Stevenson and her daughter before they disappeared.

According to a Crown case statement tendered during Holdom's committal hearing, NSW Homicide Squad detectives interviewed him twice in October, 2015.

During the first mammoth interview, which canvassed more than 2000 questions, Holdom provided different versions.

Initially he told police he hadn't seen Ms Pearce-Stevenson and her daughter since dropping them at a Canberra motel in late 2008.

Holdom, as he told it, decided to get back with his ex-girlfriend inter-state.

So he swung by the motel, kissed Ms Pearce-Stevenson and Khandalyce goodbye and left, according to details of his interview.

Holdom said he never saw the mother and daughter again but exchanged text messages at one point.

Later in the police interview, he said he saw Ms Pearce-Stevenson in a motel the following year in Adelaide.

Then he said the Alice Springs-born mother stayed in the city for about a year after January, 2009.

Ms Pearce-Stevenson told Holdom she was going back to Queensland or back to Alice Springs "with a couple of boys she'd been talking to", court documents state.

At Holdom's request, detectives returned to interview him again days later.

Holdom claimed his former friend dropped Ms Pearce-Stevenson and Khandalyce at a bus stop and he never saw them again.

He told police that same person had disposed of Ms Pearce-Stevenson's car on his own.

After detectives charged him with murder, Holdom said: "You've got the wrong guy, you'll see."

The court heard last week that Holdom allegedly made admissions to killing the mother and child to two witnesses.

One of those witnesses made a diary note about it.

"Daniels lied to me!" the witness, who can't be identified, wrote.

"Said he killed Karlie and Khandal but there (sic) still alive. It's all over Facebook ... but he says their (sic) dead and he made them think she's alive ...

"But everything he says don't made sense app (apparently) he killed her in dec 2008..."

The witness wrote in the diary that "they found her top" and "no one knows who she is".

A T-shirt with the word "Angelic" branded across the front was found with Ms Pearce-Stevenson's bones in 2008.

In a bid to identify the remains, police released a photograph of the T-shirt. However she remained unidentified for five years.

Another witness told police that Holdom claimed he stomped on Ms Pearce-Stevenson's throat, crushed her windpipe and left her body next to a log.

Police alleged Holdom also admitted to killing Khandalyce, telling the same witness she suffocated.

Holdom is accused of stealing more than $70,000 from Ms Pearce-Stevenson's bank account, mostly in the form of Centrelink payments, in the years after her death.

Finding the prosecution had a "compelling circumstantial case", Magistrate Les Mabbutt committed Holdom to stand trial for two counts of murder.

The case was adjourned to October 6.