Almost 20 years after being found guilty of killing her four infant children, a second public inquiry will be held into the conviction of Kathleen Folbigg based on new genetic evidence.

NSW Attorney-General Mark Speakman earlier today announced plans for a second public inquiry into Kathleen Folbigg’s conviction at a press conference at Parliament House.

Mr Speakman announced the inquiry would consider whether there was “question or doubt” over her conviction in 2003 for the murder of three of her children and the manslaughter of a fourth.

“I can well understand why members of the public would shake their heads and roll their eyes in disbelief at the number of chances Ms Folbigg has had to clear their name, but it’s clear that, in the interest of justice, there has to be a further public inquiry that is open, transparent, fair and efficient,” he said.

“This has been a difficult decision but, in the end, I think there was no other option but to have some kind of a review chance for Ms Folbigg, given the way the scientific evidence has emerged, and the nature of this scientific evidence.”

Folbigg, 54, was convicted of smothering and killing her four infant children over a 10-year period between 1989 and 1999. She was sentenced to 30 years, 25 without parole, and in the process became Australia’s “worst female serial killer” and “most hated woman”.

Folbigg pleaded not guilty, insisting her children died from sudden infant death syndrome (SIDS), as attributed by doctors.

This has been a difficult decision but, in the end, I think there was no other option but to have some kind of a review.

Despite there being no evidence that Folbigg smothered her children, due to Folbigg’s concerning and closely scrutinised diary entries, she was found guilty by the jury.

Diary entries including “Sarah left with a bit of help” and “Thank goodness. It has saved her from the fate of her siblings. I think she was warned” also prompted Folbigg’s husband and father of the children to contact police.

The decision by Speakman came after a petition last year where a group of 90 medical practitioners and science leaders called on the government to pardon Folbigg. The group of professionals believe the infants died from natural causes due to the lack of medical evidence indicating death by smothering as well as a study published by Europace.

In mid-2019, Europace published a report which argued that two of Folbigg’s female children likely died from natural causes.

Speakman said the report found a genome, known as CALM2, was present in the genetic sequencing of Folbigg’s daughters. He said this was a “likely explanation for the deaths”.

CALM2 is a genetic mutation known to cause sudden cardiac deaths.

The report also found Folbigg’s two sons, may have carried different genetic mutations which contributed to epileptic fits that caused the infants to stop breathing during their sleep.

Mr Speakman said the full potential impacts of CALM2 “weren’t known” during the last public inquiry in 2019 which reinforced Folbigg’s guilt.

Main image graphic of CALM2 antibody and inquiry screenshot of Kathleen Folbigg in 2019.