The Homicide Squad is now investigating Murdoch's death. "The exact circumstances relating to the death have yet to be determined," Victoria Police said in a statement. "It is standard procedure for all deaths in custody to be investigated by the Homicide Squad." Murdoch was also jailed for leaving widow Ilona Prohaska for dead after he slashed her throat with a knife. The attacks on the women happened while Murdoch was on parole for the earlier attack of another woman in her home. She was also stabbed and beaten. READ MORE: Mother Kylie Blackwood was murdered during a robbery gone wrong.(Supplied)