THE family of a young mother killed by her ex-boyfriend in "a mad fit of jealous rage" as the 999 emergency system failed her are seeking a landmark ruling over the right to claim damages for police negligence.
Joanna Michael, 25, from St Mellons, Cardiff, dialled 999 twice, but "individual and systemic failures" by the police meant the emergency services arrived too late to save her life, the Supreme Court was told.
The highest court in the land is hearing a challenge by Joanna's family against a Court of Appeal ruling in 2012 that the police have an "immunity" from being sued for negligence under the common law for the actions of officers during "the investigation or suppression of crime".
At the same time, the chief constables of South Wales and Gwent Police are cross-appealing against the appeal judges' linked ruling that the family should be allowed to go ahead with a claim that their Article 2 rights under the European Convention on Human Rights were breached by a police failure to protect Joanna's life.
Nicholas Bowen QC, appearing for Joanna's family, said the case was "desperately important", particularly with regard to cases of domestic violence.
He told seven Supreme Court justices: "There is a need for a heightened accountability of the police in the light of recent scandals and investigations which have had a very serious detrimental affect on public and political confidence in police services."
Mr Bowen said the family legal action was "not just about money" but also a "determination to find out really and truly what happened".
He described how Joanna was killed in August 2009 by ex-boyfriend Cyron Williams, 19.
Williams broke into her home "in a mad fit of jealous rage after he discovered she was in a new relationship some weeks after they had finished seeing each other".
There was a history of domestic abuse, and Williams was now serving life with a 20-year tariff which meant that he would remain in prison at least to 2030.
Joanna made her first 999 call on a mobile phone to the police at 2.29am on August 5 2009 and told the Gwent Police operator that Williams had come to the house and found her with someone else.
He had bitten her ear hard and taken the other man away in his car - saying he would return to kill her.
Mr Bowen said the "urgency was absolutely plain" and an immediate response could have meant police reaching her in five minutes. But the call had gone through Gwent - "the wrong police force" - and not South Wales, as it should have done.
The Gwent operator told the mother-of-two to "stay put" in the house and keep the phone free as South Wales Police would want to call her back, said Mr Bowen.
According to the appeal court judgment, the Gwent operator spoke to her South Wales Police counterpart and said Williams had threatened to return to "hit" Joanna but did not refer to "the threat to kill".
The call should have continued to be graded as requiring an immediate response, but was instead graded at the next level down.
A further 999 call was received by Gwent Police from Joanna at 2.43am and she could be heard screaming before the line went dead. Police officers arrived at 2.51am. Joanna was found to have been stabbed by Williams 72 times.
Mr Bowen told the court that the "factual picture" revealed there were "crucial legal duties owed to Ms Michael's estate by the police".
He argued officers had failed to arrive in time and possibly save her life because of unacceptable delays. These were caused by individual and systemic errors of the police which justified them having to face damages claims for negligence.
Mr Bowen said the police were claiming immunity from being sued largely relying on the 1989 case of Hill v Chief Constable of West Yorkshire - the "Yorkshire Ripper" case.
He said: "There is a direct full-frontal attack to Hill for the first time in this case. If our whole case is to succeed, Hill may have to go."
The Independent Police Complaints Commission (IPCC) has already ruled that Joanna was failed by both South Wales and Gwent police.