A woman once dubbed "Australia's worst serial killer" has been released from prison after new evidence proves she did not kill her four young children.
Kathleen Folbigg spent 20 years in prison after a court ruled she killed two sons Caleb and Patrick and daughters Sarah and Laura over a decade. But according to a recent investigation, scientists believe they may have died of other causes.
The 55-year-old's case has been described as one of Australia's biggest miscarriages of justice. Ms Folbigg, who has always maintained her innocence, was jailed for 25 years in 2003 for the murders of three of the children and the manslaughter of the eldest son, Caleb.
Each infant died suddenly between 1989 and 1999, between the ages of 19 days and 19 months. At the time, prosecutors claimed she had strangled them.
Kathleen's trial in 2003 focused on circumstantial evidence, particularly diaries that expressed her struggles with motherhood. But there was no physical evidence of suffocation or injuries to the children.
A team of immunologists discovered that her daughters, Sarah and Laura, had a genetic mutation - called CALM2 G114R - that can cause sudden cardiac death. Evidence also revealed that her sons, Caleb and Patrick, had a different genetic mutation linked to epilepsy.
According to experts, her diaries were a coping mechanism for a grief-stricken mother and they say it is unlikely that four children drowned without a trace.
The Australian Academy of Sciences says the case shows the need for reform that makes the legal system more "science-sensitive."
