Kathleen Folbigg released from prison after being pardoned due to new evidence.

Kathleen Folbigg, dubbed "Australia's worst serial killer," was released from prison after spending 20 years behind bars for killing her four children. Spanish scientist Carola García Vinuesa helped to expose one of Australia's biggest injustices by showing that the children could have died of natural causes. García Vinuesa's team found a gene mutation in two of Folbigg's daughters, while the other two children had severe epilepsy and respiratory distress. A petition signed by 90 scientists and medical experts from around the world, including two Nobel laureates, helped secure Folbigg's release.