In 2003, Kathleen Folbigg was found guilty for the deaths of four of her children, and sentenced to 25 years in prison. All her children died as infants, and Kathleen has always maintained her innocence. But in the eyes of the law, she is Australia’s worst female serial killer. But now, almost two decades on, 151 scientists are petitioning for Kathleen Folbigg’s release. They have found a gene mutation in two of Kathleen’s children and believe they died of natural causes.