After 20 years of heartache wondering what happened to her daughter, Jenny Bird wept as the notorious Bega schoolgirl killer admitted she had been another one of his victims.
Ms Bird glared at Leslie Camilleri from the moment he entered the room in the Victorian Supreme Court on Monday.
She broke down, trembling and sobbing, as he pleaded guilty to murdering her 13-year-old daughter Prue Bird on or about February 2, 1992 - the day she disappeared from her home in Glenroy, in Melbourne's north.
Camilleri, 43, has admitted to committing the murder but disputes some of the facts put forward by prosecutors, the court heard.
His lawyer, Jacqui Kennedy, said Camilleri denied the prosecution's assertion that he had acted in concert with another, insisting he acted alone.
''It is still put that he acted in concert with another person. That is disputed,'' Ms Kennedy told Justice Elizabeth Curtain.
Prue disappeared from her home after her mother left her in the care of a friend.
The friend left the house briefly to pack boxes in the garage.
Police had previously alleged that Prue was murdered as payback for evidence given by her grandmother and step-grandfather over Melbourne's 1986 Russell Street bombing, which killed a police officer and injured 21 others.
Prosecutor Michele Williams, SC, told the court the Crown would no longer rely on material relating to the Russell Street bombing as a motive for the teenager's murder.
A contested plea hearing will be held on February 4.
Prue's body has never been found.
During past appeals for help from the public, Ms Bird had described not knowing what happened to her daughter as the ''cruellest'' blow.
Although she believed Prue was dead, she wanted her daughter's body returned to her for closure.
''I've bought an urn and I want to get her remains back and I want her to come where she belongs, with me,'' she told reporters last year.
Police conducted a three-day search for Prue's remains near Flat Rock Creek, north of the town of Cann River in far East Gippsland, in February.
But the search was called off after officers found nothing.
The site is near where the bodies of schoolgirls Lauren Barry and Nichole Collins were found in 1997.
The girls were kidnapped by Camilleri and an accomplice in Bega, NSW, and driven across the border to the isolated region where they were repeatedly raped and killed.
Camilleri is serving life without parole for those murders. AAP