A man has been charged with murder and a critical incident has been declared in two separate suspected domestic violence incidents.
Police and paramedics were called to Lurnea in Sydney's southwest on Friday afternoon after reports of a domestic assault.
A 58-year-old woman was treated at the scene and taken to Liverpool Hospital with serious head injuries.
NSW Police Acting Assistant Commissioner Trent King said a weapon was found at the scene of the alleged attack.
A man known to her who had fled the scene was located a short time later in a nearby suburb, he told reporters on Saturday.
The 60-year-old was treated by paramedics at an address on Spica Street in Sadleir before being taken to Westmead Hospital, where he died a short time later.
Mr King said the man's condition had det