Edwards, 63, was last month found guilty of murdering 55-year-old Sharon Margaret Edwards in Grafton in 2015 after she found love with another man.
Judge Justice Robert Allan Hulme said Sharon’s lover, football coach Billy Mills, was the last person to see her alive, besides Edwards.
Mills held her hand and kissed her goodbye, hours before her murder.
Hulme said it was likely Edwards killed Sharon not long after she’d arrived home after dropping Mills off.
Precise events undetermined
“Precisely what happened when Ms Edwards returned to (her home) cannot be determined,” Hulme said at Coffs Harbour Supreme Court on Wednesday.
“Only one person alive knows that.
“It is likely that after killing her and before taking her body away, he was occupied with cleaning and tidying the scene."
Her body has never been found.
During sentencing, Sharon was described as a “shining light within her family” and the wider community.
“She loved life and she was much loved,” Hulme said.
Sharon was excited about the prospect of a future with Mills, with whom she had reconnected on Facebook in 2013.
Edwards and Sharon, who were married in 1982, had three sons together – who are now aged in their 20s and 30s.
She had been over the moon about the recent birth of her first grandchild and the upcoming wedding of one of her sons.
After her death, Edwards sent messages to Sharon's phone and visited the school where she worked, looking for her.
He then reported her missing.
"Thereafter the offender set about creating the impression that he was a distressed husband whose wife had gone missing," Hulme said.
"He told many lies."
Two weeks after her death, Edwards made a tearful plea, alongside his two sons in a police press conference, for anyone with information to come forward.
Hulme said the motive for the killing was clear.
"The offender could not accept that Ms Edwards had a right to autonomy, a right to choose her own course in life," he said.
"He could not longer accept that she no longer wanted to be in a relationship with him and was enraged by her choice to engage in a relationship with Mr Mills.
“He considered himself entitled to insist that Ms Edwards conformed to his wishes rather than pursuing her own."
Edwards, who had an affair during the marriage with his current partner, will be eligible for parole in June 2035.
This story first appeared on 7NEWS and has been republished here with permission.