Brian Earl Johnston, 37 faced Brisbane Supreme Court on Wednesday having previously pleaded guilty to murdering Kelly Wilkinson on April 20, 2021.
Johnston was the estranged husband of Ms Wilkinson, who had been granted multiple court orders that attempted to protect her.
Justice Peter Applegarth said he was limited by law in the sentence he could impose and would likely agree with Ms Wilkinson's family if they said it was "not enough" for the "horrendous crime".
Crown prosecutor Philip McCarthy said Johnston stabbed Ms Wilkinson, a mother of three aged 27, multiple times in the neck and chest before setting her alight at her Gold Coast home.
Johnston, a former US marine, admitted breaching a domestic violence order and his bail conditions.
"Attending her home with the intent of killing her ... I could not imagine a worse breach," Mr McCarthy said.
Justice Applegarth said Johnston had committed a premeditated crime of "extreme domestic violence" and society had to make fundamental changes to end the scourge of violence against women.
"No one is someone else's possession," he said.
Johnston arrived at Ms Wilkinson's home armed with multiple knives and a 20 litre can of petrol before attacking her about 6.30am on her backyard patio.
He also brought a bag containing duct tape, zip ties, sedatives and an item he had intended to use to take his own life.
Johnston was arrested two blocks from the home suffering from extensive self-inflicted injuries.
Defence barrister Kim Bryson said Johnston was remorseful, and was exposed to domestic violence and excessive physical discipline as a child.
Ms Bryson said Johnston had been discouraged from seeking mental health treatment during his military service for depression and post-traumatic stress.Â
The relationship broke down in 2021 over allegations Johnston had physically, emotionally and sexually abused Ms Wilkinson.
Johnston has denied the assaults but Mr McCarthy said he was aware of the allegations before he murdered Ms Wilkinson.
She was so afraid of Johnston that she gave her family a secret phrase she would use in text messages to indicate she was under duress.
Danielle Carroll told the court Johnston's "pure evil" decision to destroy her sister's body had robbed the family of being able to properly say goodbye.
"You have caused me and those around me a lifetime of immeasurable suffering," Danielle said.
Johnston will be eligible to apply for parole 20 years after the date of his arrest.
Another man was charged in July 2021 with murder and faces trial for allegedly providing assistance that was instrumental in the crime.
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