A cunning husband infatuated with his teenage lover and babysitter laid out a number of dominoes leading to the murder of Lynette Dawson in 1982, a judge has been told.

In the NSW Supreme Court on Tuesday, crown prosecutor Craig Everson SC argued that Christopher Michael Dawson, now 73, had killed his wife on January 8 or 9, 1982 after numerous attempts to start a relationship with his former high school student, known as JC, had failed.

“By now the Crown contends that the accused had his dominoes all lined up and they were ready to fall,” Mr Everson said during closing submissions.

Dawson was alleged to have tried in four different ways to get out of his marriage before resorting to murder, including moving into a flat in Manly, Sydney with JC, hiring a third party to murder his wife, selling the matrimonial home in Bayview, and moving with JC to Queensland to start a new life.

All of these plots failed, Mr Everson said, meaning a husband who was infatuated and besotted with his teenage lover reached a critical point of desperation and resorted to murder.

Justice Ian Harrison was taken through events from when JC started babysitting for the Dawsons in 1980 until Mrs Dawson’s disappearance in early January 1982.

Dawson’s obsession with JC caused him to ward off and threaten teenage boys who were attracted to her, and publicly attending her high school formal as her date, the court heard.

By December 25, 1981, Dawson had slid so far into moral turpitude that he had returned from his aborted trip to Queensland with JC and hid the fact that he was back from his wife, instead staying at his twin brother Paul Dawson’s home, Mr Everson said.

Dawson was alleged to have abandoned his family on New Year’s Eve 1981 as well to spend time with JC, and grew upset when JC wanted to end the relationship in early January 1982, flying to Southwest Rocks for a holiday with her friends.

At a marriage counselling session on January 8, the day of the alleged murder, Dawson purportedly put his hands around his wife’s throat, telling her that if this did not work, he would get rid of her.

The Crown contends Dawson disposed of the body on the night of January 9 after a meeting with family friend Philip Day and Mrs Dawson’s mother Helena Simms at Northbridge Baths.

At the baths, Dawson claimed he received a call from his wife saying she needed time away. However, Mr Everson argued that the call was a fabrication, saying no one had actually seen him take the call or heard what was said.

Dawson is alleged to have driven to Southwest Rocks through the night of January 10, arriving there the next day and driving back with JC to Sydney where she moved into the Bayview home.

This haste for the trip so soon after Mrs Dawson vanished showed Dawson’s enthusiasm for JC and was inconsistent with his claims his wife would be back home in a couple of days, Mr Everson said.

Dawson’s version of events, that Mrs Dawson had simply left home without warning, was inconceivable, the court heard. Evidence showed she was looking forwards to her future after marriage counselling, and that she had remained committed to her “Chrissy” even while he was spending time with JC in late 1981.

Mr Everson urged the court to find that JC was a credible witness, despite Dawson’s legal team arguing that she had made up allegations against him due to an acrimonious custody battle when the couple separated in 1990.

While JC had only gone to the police in 1990 with allegations that Dawson had wanted to hire a hitman to kill his wife, she had also made these same claims to her friends and Mrs Dawson’s family at the time.

“The conduct of (JC) and the disclosures that she made to those people are consistent with a person coming out of a controlling relationship who was scared and talking about what she knew,” Mr Everson said.

Dawson has pleaded not guilty to the murder charge, denying any involvement in his wife’s disappearance.

The trial continues.

– AAP