They were dubbed the Irish 'Scissor Sisters' after they were accused of murdering and dismembering their mother's boyfriend in a case so gruesome it still stands out today.
Charlotte and Linda Mulhall stabbed and chopped up Farah Swaleh Noor after a night out with mum Kathleen turned into murder and mayhem.
But how were they caught and how did investigators eventually solve the mysterious case? Nicola speaks with retired Chief Superintendent Christy Mangan, who headed up the case.
In part one of the interview, he recalls the day he was contacted with news that there were body parts in a Dublin canal and the subsequent battle he had to identify the victim.