0627 GMT July 17, 2019
Police found the remains of three young girls, as well as those of their mother and grandmother at an unassuming detached family home near the southwestern city of Perth on Sunday, AFP wrote.
The gruesome discovery came after a 24-year-old man, who has not been named, walked into a police station in a remote mining area some 1,500 kilometers (900 miles) north of the city.
He was due to appear in court via video link later Monday.
The family has not been formally identified, but Australian media named the mother as Mara Quinn, a fly-in fly-out worker — an employee who is flown in temporarily to a remote location for a period of time — for a West Australian mining firm.
Her children were named as three and a half-year-old daughter Charlotte and two-year-old twins Alice and Beatrix, and her mother as Beverley Quinn, 74.
The police did not release details about when and how they were killed, or the family's relationship with the man.
A Facebook profile believed to be Mara Quinn's showed her cradling a newborn in her arms, with a man beside her, and stated that she was engaged in August 2014.
A real estate listing showed a modest three-bedroom house and a standalone garage.
'Silence for a week'
A neighbor told ABC he had returned from a holiday to ‘silence in the street’.
"We noticed that the house next door was pretty quiet, which was unusual," Richard Fairbrother, who lives next door to the family's house, said.
"We could hear and see the kids playing in the backyard quite often."
Other neighbors spoke of a shocked community that had been close, calm and peaceful.
Mass killings are rare in Australia, but this appears to be the third such family tragedy to hit the Western Australian state in recent months.
In July, a man allegedly killed his mother and two siblings. A grandfather shot dead his wife, daughter and her four children in murder-suicide in May.