That was the message from experts who spoke at a perpetrator intervention forum this week in Canberra. But to do that, services would need to be more cohesive and collaborative, they said.

Stopping Family Violence chief executive Damian Green was among a panel of people with expertise in areas to help prevent family violence. He spoke about the impact of violence of violence on children who witnessed it.

He said on average, every man who perpetrates family violence will have an ongoing influence on three current or former partners, and potentially numerous future families. On average, these families will include two to three children.

"We need to build systems that enable us to intervene earlier and prevent the behaviours happening in the first place," Mr Green said.

He said we have the tools to do it, it's just not being done.

ACT Family Safety Co-ordinator General Jo Wood was a convener of the forum, along with Victims of Crime Commissioner Heidi Yates.

Ms Wood said a big part of her work is joining up services across different parts of the system.

"At the core of our approach is the understanding that families need a range of different supports and will start in a range of different places," Ms Wood said.

She said they were working on bringing help to people where they were already engaging with services, like the hospital where Legal Aid ACT now has an outreach service in the maternity ward.

She said her office was trying to address the question of how to reduce barriers for people seeking help, how to reduce stigma and how to bring the right help to people at the point when they were going to be receptive to it.

That's part of the role of Legal Aid ACT Family Advocacy Social Support worker Tim McCann. He approaches men who use violence against women when they're at court, or when they come in to the Legal Aid office.

Mr McCann started in the new role in July. He said it was interesting to hear at the forum just how much trauma-informed practice was relevant in this area.

"We took a great deal of encouragement from the forum as it supports the focus that I've brought to this role of trauma-aware engagement... and non collusive practices."

He said men who use violence often use justification, minimisation, excuses and diversions to try to win over the people they're engaging with.

"If I allow too much of that to pass, or use classic social worker techniques of positive regard, non-judgmental engagement and take everything at face value, then I'm at risk as a worker of engaging in collusion.

"My role is to ensure that I do not become his ally in his use of violence."

Mr McCann said everyone who comes into contact with perpetrators holds some accountability in challenging their actions, including their friends and the community.

For things to change, "everybody has to be in it", he said. He said education was important, and anybody letting things pass was helping a perpetrator justify their actions.

The forum heard that an early evaluation from the work going on in Victoria, which is aiming to implement 227 recommendations from their Royal Commission into family violence, found that accountability with a trauma-informed approach was one of six key findings to addressing perpetrator behaviour. The others were trusting relationships, family safety contact, using both individual and group work, holistic intervention and tailoring services to individual needs.