A report on common failings in call handling and domestic abuse will be released next month by the Independent Police Complaints Commission (IPCC) following an investigation which found two call handlers failed to correctly process a call from a woman later killed by her former boyfriend.

Joanna Michael was murdered in her home by Cyrons William on August 5, 2009. Attempts to call police from her mobile phone saw her call misdirected to Gwent Police, rather than South Wales Police, and call handlers failed to allocate the correct response, the IPCC has found.

Ms Michael called 999 from her mobile phone in the early hours of August 5, 2009, but problems with the 999 system saw her call misdirected to Gwent Police. The call handler graded her call as requiring an immediate response but failed to take down sufficient detail.

When the information was received by a South Wales Police control room, the lack of detail saw them wrongly demote the incident to requiring a priority response, ie, attendance within 60 minutes.

Ms Michael called 999 14 minutes later and was again misdirected to Gwent Police. Screaming was heard and she told the call handler she was in St Mellons before the line went dead. Gwent Police told South Wales Police about this latest call and the control room operator re-graded the incident as requiring an immediate response. Two officers were despatched to St Mellons, arriving five minutes later to find Ms Michael had been murdered.

The IPCC has concluded that it cannot prove that had police responded earlier Ms Michael would not still have been killed at a later time, but said she was “let down” by the service. The two call handlers will face disciplinary action.

Instances of emergency calls from mobile phones being misdirected are not common, the IPCC says, but South Wales and Gwent Police have put in place a mechanism to help them overcome the “technical glitches”.

Ms Michael was one of five IPCC independent investigations which took place in the summer of 2009 which shared common issues around call handling or dealing with domestic abuse. A separate Commissioner’s report will be issued in the next few months detailing the common findings and giving recommendations.

IPCC Commissioner Tom Davies said: “Joanna rang the police because she needed urgent assistance and was denied timely help because of a fatal combination of technological and human errors. The investigation found that Joanna’s emergency phone calls from her mobile phone were misrouted by the mobile phone mast system to Gwent Police, which did not help her situation.

“Joanna was then failed by the two police forces at an organisational level with their policies, training and communication systems between the two forces. She was further failed by the actions of the two individual call handlers dealing with her request for help. The simple fact is that at 2.29am when Joanna called 999, an immediate police response could have got to her house in five minutes.

Because of all the various failings, the emergency response did not arrive until 2.50am, when she had already been stabbed, probably at about 2.45am.

“The IPCC cannot say that an earlier response would have saved Joanna’s life. For all we know if the police had attended Joanna’s house at 2.35am, Williams may have just waited until the officers had left before resuming his murderous intentions.

“What we can say for certain is that more could and should have been done for Joanna, who was denied the opportunity for a prompt response which may have led to a different outcome. The service that Joanna received in the early hours of August 5 was below standard. Joanna, her children and her whole family have all been let down by the service received.”