Kathleen Folbigg — Australia's Most Contested Child Murder Case

Kathleen Folbigg is the Australian woman who spent more than two decades branded as the country's most notorious child killer — and who in 2023 became a symbol of what can go wrong when the justice system collides with the blind spots of science. The case unfolded in New South Wales, Australia, and spans a period from 1989 to 1999, during which Folbigg's four children died under seemingly inexplicable circumstances. What began as a tragedy evolved into one of Australia's most debated criminal cases in modern times.

The four deaths

Between 1989 and 1999, Kathleen Folbigg and her then-husband Craig Folbigg lost all four of their children. Caleb died at 19 days old in 1989. Patrick survived to nearly eight months but suffered seizures and eventually died in 1991. Sarah died at the age of ten months in 1993. The eldest, Laura, had almost reached her second birthday when she died in 1999. The deaths were initially regarded as tragic but natural — cases of sudden infant death syndrome (SIDS) or illness.

It was Craig's discovery of Kathleen's private diaries that changed everything. In them, he found passages he interpreted as admissions — fragments about anger, about a loss of control, and about a sense of guilt. He went to the police, and the investigation began.

The 2003 trial

In 2003, Kathleen Folbigg was brought to trial in Newcastle, New South Wales. The prosecution built its case largely on two pillars: the contents of the diaries and the statistical argument that four sudden infant deaths within the same family must by definition be suspicious. The then widely accepted — but since heavily criticised — logic that the probability of four natural SIDS deaths in one family is astronomically low carried considerable weight.