For more than 20 years, it was the notorious murder case many assumed would never be solved.

The disappearance of three young women in eerily similar circumstances from the upmarket Perth suburb of Claremont in the mid-1990s spooked the city like no other case before or since.

Sarah Spiers, 18, was the first to vanish in January 1996, followed by 23-year-old Jane Rimmer in June the same year and Ciara Glennon, 27, in March 1997.

The women had all been enjoying nights out with friends and each had farewelled their mates and headed home before abruptly disappearing.

Police appealed for public help on multiple occasions. ( ABC News )

No trace of Ms Spiers has ever been found.

Ms Rimmer's body was found in bushland in Wellard, on Perth's southern fringes, in August 1996, nearly two months after she was last seen alive.

Ms Glennon's body was found in the city's northern outskirts on April 3, 1997, less than three weeks after she disappeared.

After that, there was nothing.

No more young women went missing from the area in the same way and there were no more apparent breakthroughs in what was now openly referred to as a serial killer case.

Young people remained wary of going out, parents continued to warn their daughters of the dangers lurking in the shadows after dark, and everybody fervently hoped the case would be solved.

Pressure on police mounted as every day passed without an arrest.

It seemed hard to believe such brazen acts could be committed without detection, that a serial killer could lurk in the quiet suburbs of Perth without anyone knowing.

A special police unit — the Macro Task Force — had been established to solve the crime and resources were being allocated like never before.

Macro would grow to become the biggest police investigation in Australian history and detectives had several people in their sights for the crimes.

Sarah Spiers, Jane Rimmer and Ciara Glennon all went missing from Claremont. ( ABC News )

The taxi driver

Taxi drivers were one of the first groups to come under suspicion in the case.

With all three young women thought to have been planning to get taxis home from Claremont, drivers were the obvious first place to start.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 11 seconds 11 s Police take DNA swabs from taxi drivers

The only problem for police was the sheer number of taxi drivers.

In the pre-ride-sharing era, taxis were the only choice for late-night revellers trying to get home and Perth had more than 3,000 of them registered in 1996.

Thus began a massive police campaign to try to investigate every Perth taxi driver.

Background checks were conducted on all drivers in the city and their cabs were searched, leading to 78 of them losing their taxi licences.

Police undertook checks on all Perth taxi cabs. ( ABC News )

Thousands of drivers voluntarily submitted to fingerprinting and giving saliva samples in Australia's first mass DNA-testing exercise.

But the samples collected from drivers didn't match the evidence police had collected. There was no breakthrough.

One driver to attract police attention early in the piece was Steven Ross, who had told officers he believed he had given Ms Spiers a lift the night before she disappeared.

Taxi driver Steven Ross was questioned by police investigating the murders. ( ABC News )

Mr Ross lived in a granny flat at the back of a house owned by then Claremont mayor Peter Weygers, who would himself also come under suspicion in the case but has never been charged.

He said he had been driving taxis on the nights the three women disappeared, but always maintained his innocence.

He was interviewed by police but not arrested.

Then in 2004 his home was raided by Macro Task Force officers and his taxi was seized for forensic analysis. He was forced to provide a DNA sample.

Mr Ross said at the time he believed police "want a taxi driver to be charged" over the murders.

"They're trying to frame me. They can't find the killer and they're trying to put someone away," he said.

The public servant

By September 1997, police had begun to hone in on one particular suspect — a mild-mannered public servant with some odd behavioural quirks.

Lance Williams, then aged 41, lived with his parents in beachside Cottesloe, adjacent to Claremont and home to the Ocean Beach Hotel, where both Ms Spiers and Ms Rimmer had been drinking on the nights they disappeared.

The unremarkable looking middle-aged man had never been married, had recently been treated for depression following the death of a friend and came across as socially awkward and eccentric.

Lance Williams was considered by police for many years to be the prime suspect in the Claremont serial killings. ( ABC News )

It had been six months since Ms Glennon went missing and Claremont remained the focus of heavy police attention, with dozens of uniformed and undercover officers present in the area after dark.

Mr Williams attracted their attention because of his habit of cruising around the streets of the affluent suburb after dark on weekends in his white Hyundai.

Undercover female officers were a major part of the police operation in Claremont. It was hoped that the officers, dressed like the throngs of other young women who flocked to the area to socialise at night, would attract the attention of the serial killer.

When Mr Williams gave one of the officers a lift in the early hours of the morning after she asked him where the nearest bus stop was, police had reason to pay close attention to him.

They began secretly watching him day and night.

Police staked out Lance Williams' house for more than a year. ( ABC News )

Then in the early hours of Sunday February 5, 1998, they pounced, arresting him as he drove through Claremont's central entertainment precinct.

Detectives would spend more than 12 hours interrogating Mr Williams that night and well into the daylight hours — without him having a lawyer present.

However, the interrogation was not fruitful and, lacking evidence to lay charges, police released him.

But Mr Williams was far from off the hook.

By that stage officers had been watching him covertly for months — now their surveillance of him became round-the-clock, both at home and at his workplace in the Main Roads Department.

His parents' home was searched and parts of their backyard dug up, and both his car and his parents' cars were forensically tested.

It didn't take long for the media to get wind of it.

Reporters converge on Lance Williams' parents' house in Cottesloe, seeking interviews. ( ABC News )

Hungry for a new development on the case, the media's focus on Mr Williams became almost as relentless as the police's, and the farcical spectacle of Mr Williams leaving his home being tailed by police vehicles, which were being tailed by news cars, became a regular occurrence.

Mr Williams was hounded by reporters, as was his family, with his elderly parents forced to contend with packs of journalists and cameramen descending on their modest bungalow seeking interviews.

When it emerged Mr Williams had failed a polygraph, or lie detector, test administered by US expert Ron Homer, the media frenzy went into overdrive.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 55 seconds 55 s Lance Williams interviewed by the media

The fact that polygraph test results were not permitted to be used as evidence was irrelevant — finally police appeared to have made a breakthrough.

Mr Williams was ambushed by reporters as he left work, who asked him point blank if he was the serial killer as he tried to protest his innocence.

"All I had was concern, you know, that there was women walking around Claremont on their own late at night, specially from what had happened all the years before," he said.

That night, he was described on TV as the prime suspect in the Claremont case — a tag Mr Williams would wear in the minds of the public almost until the end of his life.

While police ended their round-the-clock surveillance of him in 1999, they were still undertaking searches of his home as late as 2004.

But nothing changed the fact that there was no evidence he committed the crimes.

In February 2018 Mr Williams died of cancer, aged 61.

The mayor

At the time of the women's disappearances, Peter Weygers was mayor of the Town of Claremont and president of the Civil Liberties Association of WA.

As mayor, he copped a lot of criticism from people including Ms Glennon's grieving father, Denis, that the streets of Claremont were unsafe and that not enough security measures were in place to protect people after dark.

Peter Weygers' Claremont home was searched by police. ( ABC News )

The problem for Mr Weygers was that his passionate belief in civil liberties meant he publicly objected to the use of security cameras to "spy" on citizens and the mass screening and DNA collection from taxi drivers.

Mr Weygers called on Club Bayview and the Continental Hotel to do more to improve security at their own venues and attacked the police's relentless focus on Mr Williams.

This position cost Mr Weygers his mayoral position in the 1997 Claremont Council elections and by this time he was also a person of interest in the police investigation.

Mr Weygers wanted the Continental Hotel to upgrade its security. ( ABC News )

While Mr Weygers had a strong alibi on the night Mr Glennon disappeared, having been at a late-night council meeting, he was unable to produce alibis for the nights Ms Spiers and Ms Rimmer went missing.

Police kept him in their sights.

In 2004, ahead of an independent review of the Macro taskforce and its methods, police raided homes he owned in Embleton and Claremont, including a property where his friend Mr Ross lived.

Extensive forensic tests were conducted on the houses, including checking for bloodstains, prompting Mr Weygers to accuse officers of victimisation.

"It's the most outrageous abuse of a fundamental right, a basic civil liberty … It's a gross invasion of privacy, a gross invasion of your right to have some anonymity," he thundered at reporters as police searched his home.

Mr Weygers was not arrested and no charges have ever been laid against him.

The other suspects

Police themselves were not immune from suspicion.

"We make no secret about the fact we have interviewed serving police officers," Macro chief Inspector Dave Caporn said early in the investigation.

"People aren't beyond suspicion just because they might be employed as a police officer."

Bradley Murdoch, the man who killed British backpacker Peter Falconio and abducted and assaulted his girlfriend Joanne Lees in the Northern Territory in 2001, was investigated by Macro at one point.

Bradley Murdoch came under police scrutiny for the Claremont murders, but was ruled out. ( ABC TV )

Born in Geraldton, Murdoch had worked as a truck driver and mechanic while living in Broome, but police ruled him out of their inquiries when they realised he had been in jail at the time of the first two murders.

UK man Mark Dixie, also known as Shane Turner, was another to come into the frame for the Claremont murders while working as a chef in WA during the 1990s.

After returning to the UK he raped and stabbed to death 18-year-old model Sally Anne Bowman after she left a nightclub in Sussex in 2005, and police said it was likely he had committed other crimes while in WA.

But he was officially crossed off the suspect list in December 2006, with police saying he was not in the state at the time Ms Spiers disappeared.

Profiling a 'next-door neighbour' killer

At its peak, more than 100 officers were assigned to the Macro Task Force and money came pouring in at an unprecedented rate.

The State Government provided additional policing resources, plus a foundation established by business friends of Denis Glennon went on to raise a reported $850,000.

Don Spiers (l) in front of a billboard appealing for help to find his missing daughter Sarah. ( ABC News )

This money changed the course of the investigation.

It allowed police to utilise innovative investigative techniques sourced from around the world, including a controversial lie detector machine — used on scores of suspects — and criminal profiling, which had been featured in the Oscar-winning Hollywood thriller The Silence of the Lambs.

Experts trained with the FBI and US police outlined personality sketches of the killer, which described him as a highly organised person who probably planned the murders meticulously.

Victorian police criminal profiler Claude Minisini said he would more than likely have a job and drive a recent-model car, and was probably comfortable mixing in the lively after-dark Claremont social scene. He would not frighten those he came into contact with.

Jane Rimmer's body was found in bushland at Wellard, south of Perth. ( ABC News )

David Caldwell, head of forensics at South Carolina police, said the suspect was probably quite different from the image people expected of a serial killer.

"This person is probably very bright, very much in control of himself, has all of the outward appearances of a very stable person," he outlined during a press conference in his distinctive southern drawl.

"This is probably a very pleasant, normal appearing person.

"I daresay that when this guy is arrested, I guarantee that people are going to be absolutely astounded.

"They're gonna say, 'I worked with this guy. He's my next-door neighbour. Surely it can't be?'"

Polygraph machines were among the tools used in the investigation. ( ABC News )

Polygraph expert Ronald Homer, a former FBI agent, was also flown in from the US twice to help Macro detectives test suspects.

Polygraph tests measure changes in blood pressure, breathing and sweat gland activity as a suspect is asked a series of questions, but there is widespread scepticism about their validity and accuracy, and concern they can be used to coerce the innocent into false confessions.

They are not permitted as evidence in Australia, but police defended the tests as an important screening tool to eliminate people from their inquiry.

One final suspect — the Telstra technician

The year 2016 marked 20 years since the first victim, Ms Spiers, went missing.

By this time the Macro Task Force had been subjected to at least 11 independent reviews, none of which had apparently uncovered the smoking gun.

While its detectives continued their work, people were beginning to give up hope the Claremont serial killer case would ever be solved.

Then on a hot December afternoon, just three days out from Christmas 2016, came the bombshell news many thought they would never hear.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 37 seconds 37 s WA Police announce Claremont serial killings arrest

Macro detectives had raided a home in the Perth suburb of Kewdale and had taken a 48-year-old man into custody in connection with the Claremont killings.

The following morning police held a press conference to announce the man, Telstra technician Bradley Robert Edwards, had been charged with the murders of Ms Rimmer and Ms Glennon.

Bradley Robert Edwards will face trial accused of the Claremont serial killings. ( Supplied: Central Crocs Football Club )

He was also charged with violent attacks on two other young women in 1995 and 1988, including twice raping a 17-year-old at Karrakatta Cemetery after abducting her from Claremont.

In February 2018, Mr Edwards was additionally charged with the murder of Sarah Spiers.

Police outside the Kewdale house where Bradley Edwards was arrested. ( ABC News: Robert Koenig-Luck )

He has pleaded guilty to the 1988 and 1995 attacks, but continues to plead not guilty to the three murder charges.

His trial begins on November 25.