The mother of slain teenager Christie Marceau is to speak at Parliament next week in a bid to change the law in memory of her "Princess".
Christie, 18, died in her mother Tracey's arms in November after an attack at their North Shore home.
Akshay Chand has been charged with murdering Christie and will stand trial in October.
The Herald revealed Chand was on bail at the time of Christie's death, facing charges of kidnapping, threatening and assaulting her two months earlier.
The Marceau family believe she would still be alive had the bail laws been tougher at the time.
They have joined the Sensible Sentencing Trust to launch Christie's Law, a campaign aimed at strengthening bail laws in a bid to prevent similar tragedies.
Mrs Marceau told the Herald she was overwhelmed by the support for Christie's Law.
People throughout New Zealand had been collecting signatures for a petition which will be presented to Justice Minister Judith Collins on Tuesday.
"We got 40,000 signatures, which is pretty awesome," she said. "We were not expecting that. I'd have been happy with 10,000 signatures. If 10,000 people actually cared enough, that would have been great - but 40,000 is amazing. To me, 40,000 signatures is a signal from New Zealand that things have got to change."
Mrs Marceau was nervous about presenting the petition to Parliament, and would make a brief speech.
She and husband Brian are now living in Adelaide - a move planned before their daughter died. The teenager intended to go with them and start her second year of university in Australia.
"Having the campaign to focus on has really helped us. If we can save one person, at least that's something," Mrs Marceau said.
"This is for Christie - and for the people who have gone before her. This is all we can do.
"We will always live with what happened to Christie. This is her story and it needs to be told.
"I don't want any more Christies."
This month, the Bail Amendment Bill was given a first reading in Parliament by 105 votes to 15.
If the amendment becomes law, people charged with serious crimes will have to prove to the Crown they will not be a threat to public safety if allowed out of custody.
This reverses the burden of proof for bail cases involving serious offences.
At present, it is usually the prosecutor's responsibility to prove a defendant should not get bail.
After Chand allegedly kidnapped Christie, police "vigorously" opposed bail. However, Judge David McNaughton released him to a house just 1km from the Marceaus' home.
He was on a 24-hour curfew and ordered not to contact Christie or go to her house. However, soon after his release, he allegedly killed her.
Mrs Marceau said she would welcome anyone who wanted to support the campaign to be at Parliament on Tuesday at 1pm.
She would like everyone to wear something turquoise, her daughter's favourite colour.
Christie's Law at Westpac, account number 03-0275-0644809-00 or phone 0900-723-369