One of Australia's most notorious predators, murderer and serial rapist Adrian Bayley, has been found guilty of three more brutal rapes of young women in Melbourne in the years before he murdered Jill Meagher.

Bayley, 43, raped and murdered the 29-year-old ABC staffer as she walked home from a night out in Brunswick in Melbourne's north in September 2012, in a crime that shocked the nation.

He is serving a life sentence in prison, with a non-parole period of 35 years, for the rape and murder of Ms Meagher.

Now, it has been proven beyond reasonable doubt that Bayley raped other women, including a young Dutch tourist in 2012, and two young prostitutes - one of them also in 2012 and the other almost 15 years ago.

Bayley pleaded not guilty in all three rape trials before the County Court, forcing the victims to give evidence and re-live their trauma in a series of trials that began last year and ended on Thursday.

His defence argued that while they did not dispute that the women had been victims of sexual assault, they had mistaken their attacker for Bayley because he had been so prominent in the media.

Broad suppression orders have prevented publication of any details from the three rape trials.

But with the return of the third guilty verdict the suppressions have been lifted.

Adrian Bayley pleaded not guilty in all three trials

The victim in the first trial, held in July last year, was 18 years old in late 2000, and the court heard was from a good home, but became hooked on heroin when she was 14 and turned briefly to prostitution.

In his closing arguments, Senior Prosecutor Peter Rose QC said Bayley, who worked shiftwork in a nearby bakery at the time, was the woman's third client and her last.

Horrific details emerged in court of the teenager's sustained ordeal at the hands of Bayley, after he drove her in his car into a narrow laneway in St Kilda, out of sight of passing traffic.

Raping his victims in his car after parking it in confined spaces to ensure they could not escape would become a critical hallmark of Bayley's offending.

Mr Rose said that at one point during the assault, another car drove into the laneway, and the teenager banged on the back window and mouthed "help me, please help me".

But Bayley put his fingers down her throat so she could not breathe and threatened to kill her and the car drove away.

"[Bayley] said 'you little slut, no-one will miss you'," Mr Rose told the first jury.

"She was frozen with fear ... she had never felt such fear in her life.

ABC radio employee Jill Meagher was raped and murdered by Bayley in September 2012. ( Supplied )

"She believed he was taking her somewhere to kill her."

The prosecutor told the court it would be 11 years before she told authorities what had happened, later telling police "it all added up" when she heard about Ms Meagher's murder, and saw Bayley's image.

"When she read about Jill Meagher, she immediately identified his face," Mr Rose said.

In a chilling twist of the case, the court heard when she was first approached by Bayley, the teenager had just come from a prostitutes' collective centre where she had been given a pamphlet with warnings of "bad men" who had been harassing local sex workers.

The 18-year-old was reading the pamphlet when she got into Bayley's car and told him she could not believe "how many bad people are out there".

Bayley told her he was "one of those bad guys", Mr Rose said.

Two more rapes just months before Jill Meagher attack

The victim in the second rape trial was another street prostitute attacked by Bayley several months before the fatal attack on Ms Meagher.

The court heard she was 25 years old when Bayley picked her up in his car and drove it into a narrow, dead-end laneway in Elwood in April 2012.

Bayley told his victim that it was stupid she did not have a pimp or a "spotter" looking out for her, the prosecutor said.

Key points: Adrian Bayley was brought to three separate trials from July 2014 for three rapes

Adrian Bayley was brought to three separate trials from July 2014 for three rapes One of the rapes happened in 2000 and two in 2012

One of the rapes happened in 2000 and two in 2012 He was found guilty in all three trials, after pleading not guilty

He was found guilty in all three trials, after pleading not guilty Suppression orders on reporting were lifted upon the conclusion of third case in March 2015

Suppression orders on reporting were lifted upon the conclusion of third case in March 2015 Bayley pleaded guilty to killing Jill Meagher in 2012 and was sentenced to life in prison, with a minimum of 35 years

Bayley pleaded guilty to killing Jill Meagher in 2012 and was sentenced to life in prison, with a minimum of 35 years He had previously served a total of 11 years in prison for the rape and attempted rape of a total of eight women

He had previously served a total of 11 years in prison for the rape and attempted rape of a total of eight women He was first jailed in 1991 for a minimum of three years for raping two teenagers and attempting to rape another when he was 19

He was first jailed in 1991 for a minimum of three years for raping two teenagers and attempting to rape another when he was 19 He was jailed again in 2001 for a minimum of eight years for raping five prostitutes over six months in 2000

He was jailed again in 2001 for a minimum of eight years for raping five prostitutes over six months in 2000 In 2012 while on parole, he assaulted a man in Geelong

In 2012 while on parole, he assaulted a man in Geelong Bayley was on parole when he raped and murdered Ms Meagher and when he raped two other women in preceding months

Mr Rose told the court that when the victim struck out with her legs, cracking the windscreen, Bayley told her that he could "keep her for ages" and no-one would know she was missing.

At one point during the attack, the court heard Bayley wound up the car's windows to muffle his victim's screams.

The court heard he was also preoccupied with her identifying him from his tattoos.

Eventually, she convinced him to drive to a nearby hotel to use the bathroom, and when she came out and refused his demand to get back into the car, he drove away.

It was eight months later, three months after Jill Meagher was murdered, that the 25-year-old saw a police photo on a television report about another sex attack in St Kilda and called Crime Stoppers.

The jury in the second trial took less than an hour to return a guilty verdict.

In the third trial, the victim gave evidence via video-link from the Netherlands.

The prosecutor told the court that the Dutch tourist was walking home alone from the popular Elephant and Wheelbarrow pub in St Kilda in July 2012 on the night she was attacked.

She had been walking for half an hour from the beach precinct and was almost at St Kilda Road near her Balaclava share house, when she noticed two cars parked by the side of the road.

Mr Rose said the 27-year-old was "a little drunk" and when the driver of one of the cars beckoned her over to tell her he had seen a car following her and offered to drive her home, she got in.

That man was Bayley, Mr Rose told the court, and instead of taking her home, he drove to a small dark parking space near some apartments and "stopped between two fences".

"She asked to get out ... he said no," Mr Rose told the jury.

"He said, 'you can't get out so you may as well have sex with me'.

"He then hit her to the side of the face ... he covered her mouth to stop her yelling and held her throat. He told her she couldn't get out and no-one would hear her.

"She was afraid she was going to be killed."

Mr Rose said the young woman capitulated in fear for her life and encouraged Bayley to come back to her house, in the hope of escaping.

When he agreed and drove her home, she ran inside screaming and locked herself in the bathroom.

The court heard Bayley took several steps inside the share house but fled when he realised other people were home.

The woman's housemates called triple-0.

"She told her housemates she thought she was going to die ... she was crying hysterically," Mr Rose said.

Two months later, Bayley attacked Jill Meagher.

He was arrested five days later at his Coburg home, and led detectives to a shallow grave on a quiet road on Melbourne's outer north-western fringe.

Bayley's phone records, obtained during the investigation of Ms Meagher's murder, showed that he was in St Kilda on the night of the backpacker's rape.

Defence argued false identification of Adrian Bayley

The media blackout extended across all three County Court trials and jurors in all three of them were told nothing of the other cases pending against Bayley.

But such is Bayley's notoriety in light of Ms Meagher's rape and death, the court and lawyers took the extraordinary step of telling the pool of potential jurors at each trial exactly who he was in relation to that crime, right from the beginning.

"That is Adrian Bayley," said defence lawyer Saul Holt, pointing across the courtroom during his opening statement in the third trial, just concluded.

"You know who he is."

Mr Holt said even if jurors had not been told of Bayley's background, "you would probably have found out on your own anyway".

"Please remember when you were empanelled, you were confident you could be impartial," he told the jury.

"You took an oath to try this case only on the evidence. Please don't fill in the gaps ... distasteful as [the Jill Meagher case] is."

Judge Sue Pullen also cautioned the jurors.

"It's absolutely essential you put it out of your minds completely," Judge Pullen said.

"It is essential not to look on the internet ... or to investigate the background of Mr Bayley.

"We all have biases, we all have prejudices. I don't expect everyone to lose them overnight but ... you have to make a decision coldly, clinically."

In all three trials, Mr Holt told jurors the defence did not dispute the victims were brutally raped, and that "something awful" happened to them.

But he told the juries, the victims had it wrong.

"In September 2012 he was arrested for the rape and murder of Jill Meagher and his details were everywhere ... she [the victim] has identified things that she says were from him and that she's got elsewhere," Mr Holt said in the second trial of Bayley.

"Use your head, not your heart. Suspend your disbelief about the fact that I would defend him after all that you know about him.

"She [the victim] has jumped on the Adrian Bayley bandwagon."

In returning three guilty findings, the jurors ultimately disagreed.

One of Victoria's most violent criminals

The convictions add to a virtually unsurpassed record of violent sexual offending from a man in and out of prison and on the radar of authorities over many years, who was on parole when he attacked some of his victims, including Ms Meagher.

That last fatal attack on Ms Meagher horrified the community, leading to an enormous outpouring of grief and anger, with mainstream and social media coverage of a volume never seen before.

The extent of Bayley's offending was last revealed when he was sentenced by Supreme Court Justice Geoffrey Nettle in June 2013 to life in prison for the rape and murder of Ms Meagher.

"As your criminal record reveals, you are a recidivist violent sexual offender ... in terms of moral culpability your killing of the deceased ranks among the worst kinds conceivable," Justice Nettle told Bayley.

At the time, it emerged Bayley had been targeting, threatening and raping women his entire adult life.

His victims included his 16-year-old sister's friend 25 years ago, a teenage hitchhiker and a series of St Kilda street workers in 16 rapes a decade later.

It was those crimes Bayley spent eight years in prison before his release on parole in 2010.