For 30 years, United States social worker Dorothy Stucky Halley has been trying to understand the motivations of domestic violence perpetrators.
"About five years into running [a domestic violence] shelter, I realised when Tina walked into my office that I was speaking with the seventh victim from the same offender," she said.
"And that really made me stop and think that, while it is critical to continue to provide services to victims and children, we are never going to stop domestic violence through that work."
The revelation led her to co-found the Family Peace Initiative (FPI), a certified batterer's intervention program, with her partner Steve Halley.
They run the men's behaviour program for 11 groups of offenders across four communities in eastern Kansas.
Regional New South Wales family violence lawyer Joplin Higgins saw the pair present a workshop on perpetrators in the US in 2016, and had been trying to get them to share their ideas in the Hunter region ever since.
"Their evidence-based research is phenomenal," she said.
Ms Higgins said a six-year analysis of outcomes from the 27-week intervention program in Kansas showed it had made a real difference to how formerly abusive men were treating their partners and families.
"It's 80 to 85 per cent where there's been no further interaction with the police," she said.
"They said the 15 per cent that potentially is there, is because people had the same name, so they couldn't drill down into whether or not it was the same perpetrator.
"It speaks volumes for the misgivings people have that you can't treat family violence. You actually can because they're successfully doing it in Kansas."
Ms Higgins said when the couple recently presented their Cracking the Code workshop about perpetrator motivations in Newcastle, it attracted social workers, psychologists, lawyers, and judges.
Data from the NSW Bureau of Crime Statistics and Research (BOCSAR) showed there were 21 victims of domestic violence-related murder in 2021, and more than 32,000 domestic violence-related assaults recorded by police.
The federal government announced earlier this month that it would launch a national research project to better understand the perpetrators.
Ms Stucky Halley said any research into understanding perpetrators must focus on three key behavioural categories: Survival, entitlement, and sadism.
This is the category Ms Stucky Halley believes is most important for the judicial system, victims, and advocates to understand.
She said there are two types of survival that motivate perpetrators.
The first one is where the perpetrator values the relationship, and their underlying message to their partner is, "Without you I am nothing".
The second type is where they value personal status, and their message is, "You contribute to my status. Be perfect".
"There is a group of offenders who are terrified to lose this relationship and believe having this person in their life is critical in order for them to survive," Ms Stucky Halley said.
Next is an entitlement-based perpetrator who values authority.
Their message is, "You are supposed to serve me".
Within this category, there is also the materially motivated perpetrator who values material assets, as well as authority.
Their message is, "I get to have what I want and you need to make it possible".
"They tend not to have close connections and see women sometimes as restrictors of their liberty, but generally interchangeable and they're always looking for who can give them more," Ms Stucky Halley said.
Finally, there is the sadistically motivated perpetrator, or "the chameleon".
They value the pleasure of hurting and having total control.
Their message is, "You are my object to play with and to torture for pleasure".
"They can easily hide and can look like they're just entitled, or even survival-based, because they're taking on characteristics and showing something that isn't real," Ms Stucky Halley said.
"They have for many years strategically done that. Most of them get into the relationship with the idea of destroying that person."
Understanding the motives behind domestic violence can help both perpetrators and victims make decisions, such as when an Apprehended Domestic Violence Order should be taken out.
"When an offender who is survival-based gets served a protection order, it's like, 'Oh she really means this'," Ms Stucky Halley said.
"So what they get out of that is, 'This protection order means it's over for good'. That is when they will be at their highest level of risk."
It can also help social workers better understand how to speak to victims when they ask for help.
The Family Peace Initiative developed a checklist of questions to get victims to open up.
Questions could include: "Do they believe they would not be OK if you were to leave them? Do they seem truly remorseful after being violent to you? Do they display extreme jealousy?".
Ms Stucky Halley said understanding these motivations was an essential component of being able to end domestic violence.
"Once research is done specific to that, then those of us who are victim advocates have more to go on, about what we need to talk to victims about so they can have the most protection," she said.