If murdered dentist Preethi Reddy understood what coercive control was, she would still be alive.
That is what Dr Reddy's sister Nithya believes, and it's why she is among a coalition of advocates, which also includes the family of Hannah Clarke, pushing for Australia to criminalise the behaviour.
On Monday the coalition comprised of six organisations, including Women's Safety NSW, White Ribbon Australia and Small Steps 4 Hannah, launched a six month campaign aiming to warn women about the dangers of coercive control and lobby governments to act.
In March last year Dr Reddy's beaten and stabbed body was found stuffed into a suitcase in her car in Sydney.
A NSW coroner found she had been murdered by her ex-boyfriend in the bathroom of a five-star city hotel after attending a dental conference.
Almost a year later, Hannah Clarke and her three children were doused in petrol and burned alive by her estranged husband on the morning school run in Brisbane.
Both women were subjected to coercive control from their ex-partners in the lead up to their deaths - behaviours that a person uses to intimidate, humiliate, surveil, and control another person.
Eighteen months on from her sister's murder, Nithya Reddy says the only thing that gives her purpose is warning other families of the dangers of coercive control.
She says learning of her sister's death was the worst moment of her life - one she is forced to relive each time another woman's murder makes the news.
"Next week, another woman is going to be killed, and the week after, the week after, and the week after that," she said on Monday.
"Every time my family hears another story, another tragedy, it's not just another story."
"It traumatises and wounds us again, and again, and again."
She says there is a reason a NSW Coroners' review of intimate partner homicides found 99 per cent of perpetrators had exhibited coercive and controlling behaviours towards the victim before killing them.
"There is no other risk factor that is higher, there's no other common thread. And that's because coercive control isn't a part of domestic violence, it forms the basis - it's the core."
"I did not know this, and neither did my sister. She would be here if she understood," she said.
Psychiatrist and Doctors Against Violence Towards Women founder Karen Williams says coercive control would be considered psychological torture if it were to be inflicted upon a prisoners of war.
"It's 2020, and Australia is signatory to seven human rights treaties, but we have not signed off on saying that this behaviour is illegal," she said.
Tasmania is the only Australian jurisdiction that has laws criminalising coercive control, but the coalition of advocates is lobbying for nationally consistent legislation, similar to that recently introduced in Scotland.
Scottish prosecutors must now prove a pattern of two or more abusive behaviours that a reasonable person would see as causing a victim or survivor fear, alarm or distress.
Within a year their introduction, more than 1000 charges had been referred to prosecutors, author and journalist Jess Hill said.
"Criminalising coercive control will not magically fix our deeply flawed justice system... but (it) will replace the broken lens we have on domestic abuse," Ms Hill said.
"Instead of seeing a collection of incidents, it will make visible the system of abuse."
Some of Australia's biggest magazines, published by Are Media, are spearheading the campaign and will share the message with their 9.75 million readers across the country.
Editor-in-chief of The Australian Women's Weekly Nicole Byers said change was long overdue.
"If these deaths were happening at the same rate on our roads or our sporting fields, action would have been taken years ago."
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Australian Associated Press