An Illawarra man will walk free from jail before Christmas for his role in covering up the death of slain teenager Louise O'Brien.
The man, who cannot be named because he was a juvenile at the time, but will turn 21 on Sunday, was yesterday sentenced to a minimum two years and nine months' jail over the 2008 crime.
However, the presiding judge agreed to backdate the start of his sentence to March 2011 when he was first taken into custody, making the man eligible for parole on December 1 this year.
A jury found him and his mother guilty of being accessories after the fact to Louise's manslaughter after a trial in Wollongong District Court in July.
The woman, 47, was last week ordered to spend a minimum three years behind bars.
In court yesterday, Judge Paul Conlon recounted Louise's last known movements on the afternoon of October 12, 2008, when it is believed she died after a hammer thrown at her by an elderly woman hit her in the head.
Judge Conlon said the man then became involved in moving Louise's body within the house and finally into his caravan at the rear of the property.
The man, with another teen, dug a hole in the backyard of the elderly woman's northern Illawarra property, in which a garbage bin containing Louise's body was later buried.
Judge Conlon said he was satisfied the man knew he was digging the hole to bury Louise's body, noting he even gave the other man instructions on what size it should be to accommodate the bin.
Judge Conlon dismissed suggestions the man's actions were "a misguided sense of loyalty" to follow directions from his mother and the elderly woman, saying there was no evidence before the court to make that finding.
The court heard in the months following Louise's death, the man and his mother repeatedly lied about the 17-year-old's whereabouts, telling her mother, Kathy McDonald, and others she had simply moved away.
The pair continued their lie even after Louise's body was unearthed in February 2011, telling investigating police who interviewed them in the days after the grisly discovery that they thought she had been living in Melbourne.
Judge Conlon said it was difficult to comprehend the callousness of the man's actions in continuing with the pretence that Louise was alive and well in the months and years after her death.
"He displayed incredible cold heartedness in maintaining the lie," he said.
The man's lawyer, Anne Healey, told the court her client's experience in Goulburn jail, where he was being held in protective custody, had been "horrifying".