The second judicial inquiry into the convictions of Kathleen Folbigg for fatally smothering her four children is being watched closely as a test case for law reform in Australia.
The woman who has been referred to as the country's worst female serial killer, was convicted in 2003 of three counts of murder and one of manslaughter.
The 55-year-old has five years left to serve of a 25-year jail sentence, and maintains her children died of natural causes over a decade between 1989 and 1999 in the NSW Hunter Valley.
For the first time since the quashing of Lindy Chamberlain's murder conviction, science is nudging the judiciary in the Folbigg case, but in a much more powerful way.
The inquiry, which is due to resume tomorrow, has been showing how forensic science and police investigative procedures are changing rapidly.
However, the judiciary moves at a slower pace.
Two days into a scheduled fortnight-long hearing in November last year, the Folbigg inquiry adjourned so retired Chief Justice Tom Bathurst KC and several expert witnesses could get their head around new evidence.
The evidence from two Danish genetics experts, Michael Toft Overgaard and Mette Nyagaard, reinforced their earlier research about a rare gene mutation.
The professors wrote a paper in 2021 stating Folbigg and her daughters Laura and Sara, had a rare gene mutation linked to heart arrhythmia and sudden death.
The mutation was not found in her other two children, Caleb, and Patrick.
In November, the inquiry heard that just weeks before travelling to Sydney to give evidence, the professors managed to reproduce the mutation, finding that it interferes with calcium binding which affects how the heart contracts.
It strengthened their 2021 research, possibly casting more doubt on Folbigg's convictions.
Australian Academy of Science chief executive Anna-Maria Arabia said the organisation had become heavily involved in the case due to concern scientific evidence at the first inquiry in 2019 was not adequately explained.
The retired District Court Judge Reg Blanch, who presided over the 2019 inquiry, found the evidence given reinforced Folbigg's guilt.
"We believe there is a role in the justice system for an independent body to identify what discipline experts are needed from to inform a particular case," Ms Arabia said.
"Currently those experts are chosen by both sides, the prosecution and defence, but they are cross examined in a legal system that is adversarial.
"Pitting scientists against each other is probably not going to give any judge or commissioner the information they need to inform their decisions at that time."
Ms Arabia said new scientific evidence came to light after Folbigg had exhausted all avenues of appeal, but there was no official systematic way to deal with it.
A petition was sent to NSW Attorney-General Mark Speakman for Folbigg's release, but Ms Arabia questioned whether it was appropriate for a member of the government to make that decision.
"As a citizen I expect it to be made by the judicial system and Mark Speakman perhaps did feel uncomfortable making it, so asked for this second inquiry to return the matter to the justice system."
Countries such as the UK, New Zealand, Scotland, and Norway have introduced "Criminal Case Review Commissions" to deal with post-appeal phase new evidence.
"They are like-minded countries with comparable judicial systems to Australia and we are lagging behind," Ms Arabia said.
"It is usually human error or the wrong information that has led to an incorrect incarceration, not a corrupt justice system or one that doesn't work."
Forensic anthropologist and criminologist Xanthe Mallett came across the case when she was writing her book Mothers Who Murder.
She said she raised the possibility Folbigg's guilt could not be proven beyond reasonable doubt in 2014, when it was unpopular to do so.
Dr Mallett said the latest scientific developments were a seismic shift for the legal system.
"Science is saying her guilt can't be proven beyond reasonable doubt because of what we now know about genetic mutations for at least two children, and the legal system is struggling to cope with the level of change and detail."
Dr Mallett noted that to get the second judicial review, about 90 scientists made a submission to Mr Speakman, an unprecedented move.
She said people around the world were watching because Australia's justice system was under the microscope.
"What we have is a conviction for three murders and a manslaughter based on tendency evidence, with all the cases heard together," she said.
"If you take out two cases because two children died because of bad genetic mutations, then there is no pattern anymore.
"The only evidence remaining is tendency evidence and Ms Folbigg's diaries, that are entirely subjective and open to interpretation."
The next phase of the inquiry is expected to run for three weeks to address more cardiac and genetic evidence as well as psychology and psychiatry.
It will also cover evidence relevant to the damning diary entries in which Folbigg talks about her struggle with motherhood.
Folbigg has not been called to give evidence at this inquiry.
If Mr Bathurst finds the new evidence does suggest there is reasonable doubt about her guilt, he can refer the case to the Court of Criminal Appeal to consider if her convictions should be quashed.
