Wife-killer Dawson likely to die in jail

More than 40 years after killing his wife Lynette and disposing of her body, former Sydney schoolteacher Chris Dawson will now spend at least 18 years in jail.

On Friday, Justice Ian Harrison delivered a maximum sentence of 24 years in the NSW Supreme Court, noting the 74-year-old would likely die behind bars after being found guilty of murder in August.

"Mr Dawson is not old by contemporary standards, but the reality is that he will not live to reach the end of his non-parole period," the judge said.

He called the murder, which occurred in the couple's Bayview home in January 1982, an objectively serious crime inspired by Dawson's "uncontrollable desire" to be with his teenage lover, known as JC.

"The prospect of losing her distressed, frustrated and ultimately overwhelmed Mr Dawson to the point he resolved to kill his wife," Justice Harrison said.

JC was Dawson's former high school student and also worked as the couple's babysitter in 1980 and 1981. The pair eventually married in 1984 and divorced in 1991.

Mrs Dawson would not have known what was coming on that fateful night in January 1982, the judge said.

"Lynette Dawson was faultless and undeserving of her fate," he said.

Claims media hype behind the four-decade-long mystery served as some extra punishment which should shorten the jail sentence imposed were rejected by the court.

"Mr Dawson has now been convicted of the crime which attracted the publicity in question. In those circumstances … Mr Dawson is now the author of his own misfortune," Justice Harrison said.

The decision concludes a long wait for justice for Mrs Dawson's family, who are still pleading with the convicted wife-killer to reveal the location of her body.

Dawson was given a non-parole period of 18 years, expiring August 29, 2040, meaning he will be aged in his 90s before he can apply for release from jail.

His maximum jail term will expire on August 29, 2046.

During the sentence hearing in November, crown prosecutor Craig Everson SC said Dawson had planned a "deliberate and conscious act" of domestic violence with an intention to kill.

He said a crime of "very great heinousness" required a term of life imprisonment. 

Dawson's lawyer Greg Walsh disputed claims the crime was at the high end in terms of objective seriousness.

Mr Walsh said the former Newtown Jets rugby league player had already suffered under the "most constant and egregious publicity" for four decades.

His health was also deteriorating, the court heard, with Dawson showing signs of chronic traumatic encephalopathy, a brain condition often experienced in contact sports.

Dawson has filed an appeal of his conviction.

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