Assistant Commissioner Leanne McCusker said police received a phone call from Shaun King at a home in St Marys about 8.40pm on Tuesday over concerns for his own welfare but officers did not attend the home.
Police were called again about 6.45am on Wednesday by a woman at the residence and arrived to find King’s partner, Drew Douglas, with stab wounds to her chest.
Paramedics tried to save Douglas but she died at the scene. Police arrested King at Campbelltown Police Station about 7.30am on Wednesday.
The 35-year-old was charged with murder later on Wednesday and refused bail to appear in Campbelltown Local Court on Thursday.
Homicide detectives and Nepean police are investigating Douglas’ death.
“There is a history of police involvement with both these two people,” McCusker said.
A critical incident team from Ryde Police Area Command will investigate the incident and police response as a whole, police confirmed.
That investigation will include why police did not respond to the welfare check call on Tuesday night, McCusker said.
Neighbours were left “unsettled” by the death in their suburban street.
”I’ve been here all my life, never had a murder here,” a neighbour said.
“Not what you really want to hear.”
The Law Enforcement Conduct Commission, which investigates allegations of police misconduct, has been notified and will independently monitor the probe by NSW Police’s Professional Standards Command.
