Kylie Maybury's killer 'a marked man'

A court has heard that the 'monster' responsible for raping and murdering a six-year-old in Melbourne's north will live in fear of being attacked in prison for the rest of his life.

Gregory Keith Davies, 75, pleaded guilty to raping, strangling and drugging Kylie Maybury inside his car in Preston in November 1984.

Her body was found the following day in a nearby gutter, just 650 metres from the house Davies was living in with his mother.

It took more than 30 years for police to ask him for a voluntary DNA sample, which was a match to the semen found on the young girl's clothes.

Detectives had ruled him out as a suspect decades earlier when he provided an alibi.

Despite pleading guilty at the start of a committal hearing in the Melbourne Magistrates' Court, Davies still maintains he cannot remember raping and killing the young girl.

The court heard Kylie's grandfather killed himself in the wake of her death while under suspicion of involvement, and her uncle also took his own life several years later.

Kylie's mother told the court that her daughters death had destroyed her life.

The court also heard Davies was previously attacked by fellow prisoners when boiling water was poured on his neck and groin.

He required skin grafts as a result.

Davies' defence barrister David Gibson said his client would always remain a target, 'he will always be in protection, he will be a marked man ... there is nowhere safe for him'.

Davies had prior convictions for dishonesty offences, and was acquitted of attempted murder in 1971 for attacking a 14-year-old girl, due to insanity.

As he was led from the dock, a man in the court yelled 'you piece of shit'.

Davies will be sentenced on December 15, 2017.