Ninety eminent scientists - including two Australian Nobel Laureates - have called for the release of a convicted NSW child killer.

Kathleen Folbigg was convicted and jailed in 2003 for murdering her children Patrick, Sarah and Laura and for the manslaughter of her son Caleb.

The children died years apart, Caleb in 1989, Patrick in 1991, Sarah in 1993 and Laura in 1999. 

The scientists have signed a petition arguing that Ms Folbigg should be granted a pardon based on the significant scientific evidence of natural causes of death for her children.

A series of articles in the science press COSMOS have gone through breakthroughs that they say shifts the weight of evidence in the case.

Ms Folbigg was found to have smothered her children, but new scientific discoveries throw the case into question, they say.

“This long list of incredibly learned and eminent Australians is demanding justice be served,” said Ian Connellan, editor-in-chief of the Royal Institution of Australia and publisher of COSMOS.

“It may also prove to be pivotal, in the way our courts are geared to accept peer-supported scientific evidence, including relatively new discoveries, especially when pitted against otherwise circumstantial details.”

Ms Folbigg’s conviction was based on circumstantial evidence and evidence from her diaries. The prosecution argued that it was unlikely four of her children could die suddenly and unexpectedly in their sleep.

However, forensic pathologists had raised concerns over some of the medical evidence provided at the trial, leading to a judicial inquiry into Ms Folbigg’s convictions in March 2019.

Medical records showed all four children suffered from a series of conditions. Caleb had difficulties breathing since birth, Patrick suffered epileptic seizures, and Ms Folbigg’s daughters Sarah and Laura had respiratory infections in the days before their deaths.

The scientists say this suggests there was a single underlying natural cause, likely genetic, that led to the different manifestations and lethal triggers.

They hypothesise that rare inherited genetic variants could be responsible for the cardiac or respiratory disorders that led to the children’s sudden deaths.

Professor Carola Vinuesa, from the Australian National University, explains the new thinking.

“Given that it was much more complicated to extract the genome of the children, there was a chance that Kathleen herself might be carrying one of these variants, because they tend to be inherited,” Vinuesa said in a statement.

Variants that cause sudden death in children can remain silent in some individuals, allowing them to carry the mutation but grow up as a healthy adult.

“So Folbigg could have been carrying these mutations and passed them on her children,” Prof Vinuesa said.

All of the children had underlying conditions or a mutated gene that could have led them to die of natural causes within a short window of time. 

Two of the children had a condition linked to improper heartbeat, which can cause sudden cardiac death.

The scientists say that the mutation in the CALM2 gene shared by Sarah and Laura Folbigg is likely pathogenic, and so provides a reasonable explanation for their deaths, which in turn creates reasonable doubt that their mother killed them.

At the very least, they say this should be adequate to reassert the presumption of innocence.

“If you do not take genetics into account, it would seem an exceptionally rare scenario to have four natural deaths in a family,” Prof Vinuesa said.

“Actually it isn’t.

“In all four Folbigg children, there is credible medical and pathological evidence, including new peer-reviewed genetic findings, by an international team of 27 scientists published in a top international cardiology journal last year, that points towards natural causes of death.

“It is our responsibility as scientists to assist our legal peers so that they can rely on scientific, peer-reviewed evidence and ensure that domain experts are at their disposal to solve the issues of a difficult legal case.”

The petition concludes:

“The executive prerogative of mercy is designed to deal with failures of the justice system such as this one. It is incumbent on the Governor to exercise her power to stop the ongoing miscarriage of justice suffered by Ms Folbigg. Not to do so is to continue to deny Ms Folbigg basic human rights and to decrease faith in the New South Wales justice system.

“Ms Folbigg’s case also establishes a dangerous precedent as it means that cogent medical and scientific evidence can simply be ignored in preference to subjective interpretations of circumstantial evidence.”

Australian Academy of Science President, Professor John Shine AC FRS Pres AA is among the petition’s signatories.

“Given the scientific and medical evidence that now exists in this case, signing this petition was the right thing to do,” Professor Shine said.

“These matters are incredibly complex. As our scientific knowledge deepens, so does the complexity, which makes the job of the courts a more complex one too.

“We want to work more closely with the legal community to ensure evidence placed before courts is presented in the most accurate way possible, using the most appropriate experts and the most up-to-date science,” Professor Shine said.