An Australian mother jailed for killing her four young children was released on Monday after 20 years behind bars, ending what authorities called a “terrible ordeal”. Kathleen Folbigg was dubbed “Australia’s worst female serial killer” after she was convicted in 2003 of murdering three of her children, and the manslaughter of a fourth. Prosecutors argued she suffocated the children, who died between the ages of nine weeks and three years, but Folbigg has steadfastly maintained each death was due to natural causes. In 2021, dozens of scientists from Australia and abroad signed a petition calling for Folbigg’s release, saying new forensic evidence suggested the unexplained deaths were linked to rare genetic mutations or congenital abnormalities. New South Wales Attorney-General Michael Daley said Folbigg has been pardoned following a year-long inquiry — launched in May 2022 — that established “reasonable doubt” surrounding the convictions. “This has been a terrible ordeal for everyone concerned, and I hope that our actions today put some closure on this 20-year matter,” he told reporters. Folbigg, 55, was released on Monday morning from a prison in Grafton where she had been serving a sentence of at least 25 years.