Dawn Smith has remained stoic for 37 years.

She has spent every one of those years imagining who her daughter, Jacinta Rose "Cindy" Smith, might have become — what life she could have lived if she had grown up like so many other children.

"I've always wondered what she would have been like today, whether she would have married and had kids," Aunty Dawn told reporters on a windy day in Sydney.

"You think of all of these things. I miss her very much."

In December 1987, Aunty Dawn lost 15-year-old Cindy and her 16-year-old niece, Mona Lisa Smith, in a car crash near Bourke, in the NSW outback.

"They were good girls," Aunty Dawn said. "They kept to themselves — everyone loved them."

Described as "like sisters," the girls were found beside the wreck of a ute on the Mitchell Highway between Bourke and Enngonia. Ian Alexander Grant, a 40-year-old non-Indigenous man, was found by witnesses with his arm draped across Cindy's bare-chested, partially naked body.

Grant was later acquitted of driving-related offences, and a further charge of interfering with a corpse was dropped just before trial.

In a harrowing inquest in late 2023, former detective inspector Paul Quigg testified that Grant should have been charged with manslaughter.

Now, nearly four decades later, Cindy's legacy is set to shape the law. On Wednesday, the NSW government introduced legislation to close a legal loophole that had shielded Grant from prosecution for alleged sexual violence.

'Cindy's Law' will ensure that if someone sexually assaults or interferes with a body after death, they cannot escape prosecution simply because the time of death is uncertain — as it was in Cindy and Mona's case. If it's proven beyond reasonable doubt that one of the crimes occurred, but it's unclear which due to uncertainty around timing, the offender will be sentenced according to the lesser maximum penalty.

"These are very horrific circumstances, and the family has had to carry with them in their hearts for the last 37 years," said George Newhouse, Chief Executive of the National Justice Project, which represented the Smith family.

"What you're seeing today is the beginning of an amendment to laws to ensure that no family has to go through this horrific experience again — where police did not give the family the decency of a proper inquiry and the coroner themselves said that if this were two white girls, the outcome for accountability would've been totally different."

He added that while nothing could bring the girls back, "at least the family have some legacy to the future to ensure no parent has to go through what they went through."

NSW Attorney-General Michael Daley said the reform was a direct response to the inquest findings and the tireless advocacy of the Smith family.

The inquest heard the original investigation into the girls' deaths was grossly inadequate: police failed to preserve evidence, did not notify Mona's mother after her daughter died, and their actions were shaped by racial bias.

State Coroner Teresa O'Sullivan was scathing: "The uncomfortable truth, to my mind, is that had two white teenage girls died in the same circumstances, I cannot conceive of there being such a manifestly deficient police investigation into the circumstances of their deaths."

"Horrifyingly," she added, "the evidence suggests Mr Grant sexually interfered with Cindy after she passed".

Last year, NSW Police Commissioner Karen Webb rejected a recommendation to develop formal guidelines for reviewing past investigations.

At the time, Mona's sister, Fiona Smith, said the decision was disappointing but unsurprising.

"There's a long-standing history of racism in the NSW Police and it looks like it's going to continue," she said.

Asked on Wednesday whether she wanted an apology from the police, Aunty Dawn told reporters: "They don't really mean it… they look you in the face then stab you in the back."

In 2018, the National Justice Project urged then-Attorney General and current Opposition Leader Mark Speakman to order an inquest into the deaths. In 2020, then-Police Commissioner Mick Fuller responded, saying the case had already undergone "thorough independent reviews" in 2004 and 2018 and advised against holding an inquest.

"Both reviews found that an adequate investigation was conducted with the available evidence and technology at the time," Fuller said.

"...I do not believe an inquest into the deaths of Jacinta and Mona Lisa Smith will adduce new or additional information."

Reading this in court, counsel assisting the coroner, Peggy Dwyer SC, said it was "very worrying that that was said."

"The family and community have been thoroughly vindicated in the holding of this inquest," she said.

In 2022, Mr Speakman declined to proceed, arguing a new inquest would not provide "any meaningful information or closure" for the families.

In her findings last year, Coroner O'Sullivan disagreed.

"Given the deficiencies in the initial police investigation which have not been catalogued or acknowledged until this inquest, the perseverance and strength of the Smith families in pursuing justice in the form of answers and a thorough investigation (albeit many years too late) cannot be overstated," she said.