Kathleen Folbigg has spent 19 years in jail after being convicted of killing her four children

Kathleen Folbigg was convicted in 2003 for the murder of three and manslaughter of another of her children, but new scientific evidence could lead to her release from prison.

In 2003, Kathleen Folbigg was found guilty of the murder of three of her children, Caleb, Sarah and Laura, and for the manslaughter of her second born, Patrick, between the years 1989 to 1999.

She maintained they died of Sudden Infant Death Syndrome. And there is now an inquiry into the conviction due to new scientific evidence.

With no forensic evidence presented in her trial to support smothering, the idea that more than one sudden infant death in a family was suspicious was introduced by the forensic pathologist Dr Allan Cala who conducted the autopsy on the fourth child, Laura, who died just shy of 19 months.

She had heart inflammation, or myocarditis, but Dr Cala marked her death ‘undetermined’ because he was aware of three other deaths in the family and could not rule out homicide.

“The possibility of multiple homicides in this family has not been excluded. If homicidal acts have been committed, it is most likely these acts have been in the form of deliberate smothering,” he wrote on the autopsy report.

LISTEN TO THE EXCLUSIVE PODCAST, MOTHER’S GUILT: THE KATHLEEN FOLBIGG STORY. PRESS PLAY HERE.

At the time there had been a spate of wrongfully convicted mothers in the UK who were jailed for killing their babies based on the now debunked theory of British paediatrician Sir Roy Meadows who claimed ‘one sudden infant death is tragic, two suspicious and three murder, unless proven otherwise.’

The Crown’s case was that Folbigg found her children an irritant that got in the way of her having more sleep or going to the gym and that she intended to kill them either in a flash or anger, or attempted to render them unconscious so she could get more sleep.

Kathleen Folbigg heading to court during her trial of 2003. Picture: Stephen Cooper.

Caleb, who died at 19 days of age, had a floppy larynx, Patrick died of epileptic seizures at eight months of age, Sarah had a displaced uvula (a fleshy extension at the back of the soft palate which hangs above the throat) that can cause SIDS and Laura had myocarditis, or inflammation of the heart caused by an infection.

The Crown likened the idea that the four children died of these conditions was akin to ‘some piglets. born with wings that might fly”.

Folbigg’s disturbing diary entries expressed guilt and remorse and were viewed as admissions of murder. Her estranged husband found the diaries and contacted police. Mr Folbigg gave evidence against his wife at the trial.

Psychological and legal experts now argue the entries were taken out of context. There is no overt admission in any of the entries.

Kathleen Folbigg as she appeared at the 2019 inquiry into her conviction. Picture: AAP Image/Peter Rae

Much was made of Folbigg’s emotional detachment at the trial which went against her.

Kathleen Folbigg’s biological father stabbed her mother to death when she was 18 months old and she became a ward of the state until fostered to the Marlborough family from Newcastle at age three.

Folbigg was sentenced to 40 years in jail, reduced to 25 years on appeal. She has now spent 19 years in jail.

Scientists who analysed her DNA and that of her four children found the two girls carried a mutation on a gene linked to cardiac arrhythmias that can cause sudden death. The findings led to a petition signed by 151 eminent scientists for her pardon.

FOR MORE: Click here for the full Mother’s Guilt episode rundown