In his Labour Party conference speech, Sir Keir Starmer spoke about nurse Jane Clough, who was murdered by her former partner in 2010 after he was freed on bail.
Sir Keir had met her parents, John and Penny Clough, during his time as head of the Crown Prosecution Service.
Pledging to toughen sentencing on perpetrators of domestic abuse, Sir Keir said Jane “lived in constant fear” that her abuser “would return to harm her”.
Mr and Mrs Clough told the BBC they were pleased Jane’s story was being used to protect others.
Video journalist: Nick Raikes