For the past 10 years Aaron Steedman has co-ordinated Shine's stopping violence programme for men and works with people from all walks of life.
He knows first hand about perpetrators because he was one. While arguing with his partner many years ago, he strangled her. Now he is committed to helping other men change their behaviour.
"I got into this work because I assaulted my partner. In the midst of an argument I strangled her," he said. "That was the most serious event that ever happened when I was angry. Prior to that there was no terror. She wasn't scared of me. But after that she was."
Mr Steedman was working in hospitality at the time and said he was drinking a lot and using drugs.
"I lost my girlfriend. I lost my business. I lost a lot of things ... When my life fell apart I voluntarily entered a mens' programme."
He does not excuse what he did, there is no excuse. But he is determined to use his offending to stop others.
He spoke to the Herald about the programme he runs. It spans 18 weeks and at any given meeting there are new men mixing with those part-way through, and others about to graduate.
Participants come from every background imaginable.
"Five years ago less than 10 per cent of our men were here voluntarily. Now it's 30 per cent," he said. The rest are there as a result of a court order following family violence proceedings.
"Most of the men that come here as volunteers have not actually become physically violent. They are reaching out way earlier in their relationships, well before it becomes physical."
Mr Steedman said Kiwis had a lot to learn about family violence.
"Most people when they think of intimate partner violence think of Jake the Muss from [the movie] Once Were Warriors. Men come in here and say, 'I'm not a violent man'. But compared to who? Compared to Jake the Muss you're not a violent man, but compared to Buddha you really are."
He sees men with money, men with none and men who he knows will go off after the programme and carry on being violent.
But at meetings they are all the same -- men who need help.
"It's a really safe environment, an educational environment."
The men all sit around and are invited to share their experiences.
"You don't have to go into great detail ... Get settled into the group, get used to talking and thinking about this stuff ... it takes a deep courage and vulnerability to open up, to build that trust.
"Usually by week eight, nine or 10 most guys start to report significant changes. People are noticing they are doing things differently, they are not as aggro, they are not as intense."