Italian prosecutors have opened a murder investigation following the deaths of a mother and her teenage daughter after a pre-Christmas meal last year. Sara Di Vita, 15, and her mother Antonella Di Ielsi, 50, fell ill after a lunch in their hometown of Pietracatella, located 260 km southeast of Rome. Sara's father, Gianni, the former mayor of Pietracatella, was also taken to hospital but has since recovered. Doctors initially attributed the symptoms to food poisoning, but new tests revealed the presence of a deadly poison, ricin. Although police do not currently have a suspect, this alarming discovery has shifted the focus from a possible medical negligence investigation to a homicide inquiry. Di Vita and Di Ielsi's deaths were initially blamed on medical errors after they were discharged from the hospital, leading to an investigation into the healthcare professionals involved. Ricin, which can cause rapid organ failure and death with just a tiny amount, is a highly toxic chemical derived from castor beans. There is no known antidote for ricin poisoning, making this case all the more serious.