The parents of Sophie Elliott are backing the creation of a new strangulation offence and say such a crime is often a forerunner to even more serious violence.
Lesley Elliott has appeared before a parliamentary committee to give her view on an overhaul of family violence laws that will create new offences including non-fatal strangulation, which will carry a maximum penalty of seven years' imprisonment.
Her daughter Sophie, 22, died after being stabbed 216 times by her former boyfriend Clayton Weatherston at her Dunedin home in January 2008.
Sophie's parents have since formed the Sophie Elliott Foundation, which works with police and aims to warn young women of the signs of an abusive relationship.
Lesley told MPs that Weatherston was psychologically abusive during his five-month relationship with Sophie, and physically assaulted her twice before her murder.
"The first time she went to his flat . . . and after some discussion he wanted to go to bed with her, she tried to get away, and he picked her up and flung her on the bed, chopped her in the neck and put his hand over her mouth.
"They were struggling and fell on the floor and she was able to get away. But I don't know if that would have developed into anything more. I suspect it would have."
Elliott said when she read the definition of non-fatal strangulation in the Family and Whanau Violence Legislation Bill, "I thought, 'that's exactly what he did'".
"It's one of the things that a perpetrator can do that might not kill. I see and hear it from women who tell me - that they have [experienced] the control, the power that a perpetrator can do is actually cut off part of their air supply."
Asked by Green MP Jan Logie if creating the offence would help let people know such an assault was a "very important danger signal", Lesley said she hoped so.
"There are a lot of signs. And that's why we are in this position - because we didn't recognise the signs. And there is a whole page of them that are absolutely classic," said Elliott, whose domestic violence work saw her win the Women of Influence awards in 2014.
"When I was reading up about abuse...abusers often abuse animals. And Weatherston threatened to throw his cat out the window. I thought, 'Wow'."
Lesley's husband Gilbert, who did not attend last week's select committee, in a written submission asked that the new strangulation offence be considered as a strike offence under the "three strikes" law.
Justice Minister Amy Adams said family violence victims who had previously been strangled were seven times more likely to end up being killed than those who suffered other types of violence.
Creating a new offence would let police, programme providers and judges see the offence on an offender's criminal record, enabling them to better judge risk management and safety planning.
The legislation will see more than 50 changes to the current Domestic Violence Act, including letting other people apply for a protection order on a victim's behalf.
This could happen when a victim is too scared of a perpetrator to apply themselves. Police can already initiate a protection order, and the change will let others initiate that process.
In a written submission on behalf of all district and family court judges, Chief District Court Judge Jan-Marie Doogue, Principal Family Court Judge Laurence Ryan and Principal Youth Court Judge John Walker flagged a potential problem with this change.
The legislation does not define what powers and responsibilities a person acting on behalf of a victim has, the submission states, which "may cause confusion amongst representatives as the scope of their role".
Another change is to more closely tie occupation, tenancy and furniture orders - property orders - with protection orders. The judges' submission notes under the changes people charged with a breach of a property order will be entitled to elect trial by jury.
"It is unclear how many additional jury trials might be anticipated . . . however, we emphasise that the District Court must be provided with adequate judicial resource," the submission states.
Weatherston was sentenced to 18 years without parole for the murder of Elliott - one of the longest sentences in New Zealand's history. He showed little or no remorse during the trial, and maintained he did not intend to kill her.
Lesley Elliott was made a member of the New Zealand Order of Merit in 2015 for her services to the prevention of domestic violence.