A man has been charged with murder following the death of a woman at a house in Sydney's west.
Police received a phone call from a distressed man on Tuesday at about 8.40pm that a young mother had been stabbed at St Marys.
But officers did not respond to the call and only went to the property the next morning, when they discovered a 31-year-old mother of four with fatal stab wounds.
The circumstances surrounding both the call and subsequent response is now the subject of a major internal investigation.
The woman was treated by paramedics after emergency services attended the home on Edmondson Avenue at about 6.45am on Wednesday.
A 35-year-old man has been charged with one count of murder and was refused bail. He will appear in Campbelltown Local Court on Thursday.
Assistant Commissioner Leanne McCusker said the police's lack of response to the Tuesday call and reason for officers not to attend the home until Wednesday would form part of the investigation.
"That timeline leading into this morning will certainly be very, very strongly looked at," she told reporters.
Ms McCusker said there was a history of prior domestic violence incidents at the home but she was not aware of any threats being made in the man's initial phone call.
She added the circumstances surrounding the death would also be investigated, and whether there were any missed opportunities for police to intervene before Tuesday night.
The NSW Law Enforcement Conduct Commission has also been notified and will monitor the investigation.
Ms McCusker said police took all domestic violence incidents seriously and there were strong protocols for dealing with those cases.
"Domestic and family violence is a significant and serious concern and problem across the community," she said.
"As a community, we need to continue to do more."
The news of the woman's death came on the same day federal, state and territory governments agreed for the first time to set targets for ending family violence.
Those targets included a 25 per cent annual reduction in female victims of intimate partner homicide.
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