SITTING in the dock as the details of the case were read out, the 70-year-old man held his head in his hands. An illicit affair, evidence of domestic violence, false leads…

With each allegation, Chris Dawson’s face reddened, but his demeanour remained calm, even when the magistrate announced he was being taken from Queensland to a courthouse in Sydney, where his wife had vanished almost 37 years earlier.

Her body has never been found, but 24 hours later, on December 6, 2018, Dawson was charged with her murder.

The story of Lyn Dawson’s 1982 disappearance is one of the most talked-about cold cases in Australia, and last summer it became the subject of a murder mystery podcast that gripped the world.

Over 16 episodes, The Teacher’s Pet had the twists and turns of a perfect crime thriller – a devoted wife and mother, her handsome husband and his teenage lover.

“I originally reported on this case in 2001, when a coroner first ruled Lyn had been killed and recommended her husband Chris be charged with her murder,” explains Hedley Thomas, national chief correspondent for The Australian newspaper and creator of the podcast.

“At the time there wasn’t enough evidence to prosecute, but I thought about the case a lot over the years, staying in touch with Lyn’s family, who are very decent people. It was such a cruel situation.”

After its launch last May, The Teacher’s Pet was soon regarded as one of the most compelling crime podcasts since Serial, topping the Aussie and UK podcast charts and amassing more than 25 million downloads worldwide.

Crucially, it not only brought about fresh evidence and new witnesses, but also unearthed shocking revelations of a child grooming ring, and triggered escalating public demand that Dawson finally be charged with murder.

By the time listeners reached episode 14 in August, they were left with a cliffhanger – the police had reopened the investigation and were about to dig for Lyn’s body after a witness who had heard the podcast came forward and said he knew where she might be buried.

But then everything went silent. That was until six weeks ago, when out of nowhere two more episodes dropped.

The first, at the end of November, looked at the dig – which was unsuccessful – while the second was released on December 5 with the simple title Arrest.

Hastily edited, it revealed that Dawson had been arrested earlier that day for the murder of his wife.

It was the moment desperate family and friends had waited more than three decades for.

“I was about 10 minutes into a work meeting when my phone started buzzing and didn’t stop,” says Lyn’s nephew David Jenkins, 46, who was nine when she vanished.

“Then a text came through from my sister telling me the news. It just all felt so surreal.”

Dawson and Lyn, who was just 33 when she disappeared, had seemed like the perfect couple.

Gentle and beautiful, she was a nurse who’d married her childhood sweetheart – a handsome rugby player turned high-school PE teacher – in 1970.

“She was a very loving, generous woman,” remembers David. “She loved to swim in the surf and adored organising family parties.”

After struggling to conceive, Lyn saw their two daughters Shanelle and Sherryn – born in 1977 and 1979 – as miracles, and devoted herself to being a mum.

However, behind closed doors Lyn’s perfect life was anything but. Controlling with a violent temper, Dawson was allegedly physically abusive.

“She would say they were having an argument and he’d grab her by the arms,” said Lyn’s colleague Annette Leary on the podcast. “She had bruises on the side of the neck.

Meanwhile, their former babysitter Bev McNally revealed in June: “I actually saw him hit her, once with a tea towel and once as a shove, on two separate occasions.”

Yet in their small town, the beautiful beach suburb of Bayview, Dawson and his twin brother Paul – who lived on the same street – were considered rugby league legends.

However, shockingly, the podcast also revealed that the Dawson brothers were suspected of being part of a secret predatory circle of teachers grooming students for sex.

In May this year, a former pupil at Sydney’s Cromer High, where Chris Dawson worked, spoke out about a group of at least six teachers who were having sex with students.

"The love she had for those little girls… They were her light. Her girls were paramount."

“The culture at the school was such that there were groups of men – male teachers in their 20s and 30s – who preyed on young girls at the school – 15, 16, 17-year-old girls,” said Robyn Wheeler, now 52, who was vice captain of the school in the ‘80s.

It was at Cromer High that Dawson, then 32, met troubled 16-year-old Joanne Curtis. After she began babysitting for the Dawsons in 1980, he started a sexual relationship with her.

The following year, Joanne moved into the family home, with Dawson telling his wife she needed refuge from her difficult home life.

At first Lyn welcomed the young woman, caring for her alongside her two daughters, then aged three and one.

However, when Lyn began to suspect something was going on between her husband and the teenager, she confronted Joanne, who immediately fled to Paul’s home.

It was later claimed she was in a sexual relationship with him, too.

But Joanne and Dawson reunited in December 1981, openly continuing their affair in front of Lyn, who was too emotionally broken down from years of abuse to protest.

A month after Joanne’s return, on the evening of January 8, 1982, Lyn spoke to her mother Helena Simms on the phone.

“My husband has poured me a lovely drink,” she slurred. Helena later recalled that Lyn sounded intoxicated, which was unusual as her daughter was practically teetotal. It was the last time anyone would hear from Lyn.

Dawson only reported her missing six weeks later at her mother’s insistence, claiming he thought she’d joined a religious cult.

In his statement, he said there had been problems in their marriage caused by Lyn’s spending, and neglected to mention his relationship with Joanne.

David recalls that initially Lyn’s family believed she’d left her troubled life behind and would make her way to them on the north coast.

“No one went to Sydney to look for her because we thought she’d come to us, but she never arrived,” he explains.

“At first Chris told my grandmother that Lyn was in contact with him, and she believed him. At the time we trusted him. We had no idea about the physical and emotional abuse Lyn had been suffering.

"We learned Chris was being unfaithful at the same time Lyn did, because she told family members, but we only heard about the abuse she suffered years later. We felt betrayed by him.”

Within days of Lyn’s disappearance, Joanne moved back into the Dawsons’ home, sleeping in the marital bed and looking after their daughters, who were told to call her Mum.

Three years later Dawson was able to divorce his wife in her absence, and he and Joanne married – her wedding ring made from the engagement and eternity rings last seen on Lyn’s finger – before moving to the Gold Coast.

For the next eight years there was no investigation, with police accepting Dawson’s claim.

However, not everyone was convinced. Neighbour Julie Andrew, who saw Lyn several times a week, told the podcast she didn’t believe her friend would ever abandon her kids. “The love she had for those little girls…” she recalled. “They were her light. Her girls were paramount.”

It wasn’t until 1990, when Joanne left Dawson, telling friends he’d become abusive, that questions began to be asked again.

Joanne fled to Sydney with their daughter Kristen, then five, and told police she suspected Dawson had murdered his first wife.

A homicide investigation was launched but the case fizzled out due to lack of evidence, however in 1998 it was revisited after lobbying by Lyn’s close friend Sue Strath.

Two subsequent coroner’s inquests in 2001 and 2003 attempted to determine how and why Lyn died.

Joanne gave evidence at both, testifying that Dawson had once confided he wanted Lyn dead, saying: “He told me: ‘I wanted to get a hit man to kill Lyn, but I couldn’t do it because innocent people would be killed.’”

Joanne also revealed the abuse she’d suffered, with Dawson telling her what to wear and whether she could go out, and forbidding her from making friends.

At both inquests the coroner recommended Dawson – who had declined to appear at the court – be charged with murder. However, prosecutors maintained there was insufficient evidence.

“A number of times we felt the case was at a turning point,” says Lyn’s nephew David. “But our hopes were always dashed.”

Hedley also shared his frustrations. “Justice should have kicked in following the coroners’ verdicts so Dawson could have acquitted himself or been found guilty,” he said.

“If I’d found any evidence that suggested his innocence I would have published it, but as I’ve investigated the case, my view aligned with that of the coroner and, more recently, the police.”

It was only when a new witness came forward as a result of the podcast that the police investigation was reopened. “I feel really excited because I’d kind of given up hope,” said Lyn’s daughter Shanelle, now 41, to Hedley at the time.

“I believed that she was alive for a long time. But I’ve come into more of an acceptance that she’s not any more.”

This new witness was construction company owner Joe Cimino, who had carried out work at the Dawsons’ home in 1988 and believed Lyn’s body could have been buried there after discovering disturbed soil while digging around the swimming pool.

His suspicions tallied with a police discovery of Lyn’s cardigan in 1998, which had been sliced with a knife and buried in the same place. However, no body was unearthed, and Dawson was free to go about his life on Queensland’s Sunshine Coast, where he moved with his third wife.

And while he refused to ever talk about the case, his and Lyn’s youngest daughter Sherryn, 39, broke her silence last June, describing it as a witch hunt.

“My dad’s getting hounded because there’s all these people that have got it in for him, rather than focusing on perhaps that there could be someone else,” she said.

Not all Dawson’s family have stood by him.

Since the podcast, his cousin Judy Brown has admitted that she and her husband Ray have distanced themselves.

"We decided to draw a line in the sand to honour Lyn,” she explained during a memorial walk in September on what would have been Lyn’s 70th birthday weekend. “I knew she was absolutely devoted to [her girls] and would never have left them for a day.”

And Shanelle, who has said that her mother was a “taboo subject” growing up, admitted in an interview with 60 Minutes last September: “It’s not looking good for my father, I will be honest to say.”

Now both families might finally discover the truth. The arrest came after the Office of the Director of Public Prosecutions advised NSW Police that they felt they had enough evidence that Dawson killed Lyn between 9pm on January 8 and 7am on January 9, 1982.

It’s thought that further evidence may relate to two new witnesses who came forward during the podcast, one of whom is assumed to be former babysitter Bev, while Joanne Curtis is expected to be questioned again.

Also likely to appear on the stand is Hedley, which means further episodes of The Teacher’s Pet will have to be put on hold.

Fittingly, in the final episode, Hedley asked Lyn’s family and friends how they felt about Dawson’s arrest.

While many were too shocked to fully express the relief they felt, former neighbour Julie said: “She didn’t leave her kids and now the kids will know that.”

Meanwhile, David says he’s grateful for what Hedley has done for the family. “We are coming up to 37 years since Lyn disappeared, and Hedley gave her a voice, louder than we could ever have imagined,” he says. "Chris Dawson has been incredibly lucky for decades, but now we hope his luck may have finally run out.”