Everything we know so far about the murder of three generations of women in a Perth home.

A Perth father allegedly used a blunt instrument and knives to murder his three young daughters, their mother and grandmother and then stayed in the house with their bodies for days before heading north to turn himself in.

The bodies of Mara Lee Harvey, 41, her three-year-old daughter Charlotte, two-year-old twins Alice and Beatrix and their grandmother Beverley Ann Quinn, 73, were found inside the Bedford home on Sunday.

It is alleged Anthony Robert Harvey, 24, killed his wife and children on September 3, then killed his mother-in-law the next morning when she came to visit.

It is the third domestic mass killing in Western Australia in four months.

A grandfather shot his wife, daughter and her four children before taking his own life at a farm in Osmington, near Margaret River, in May.

Just over two months later, a 19-year-old man allegedly murdered his mother, sister and brother in Ellenbrook in Perth’s northeast.

The latest grisly discovery came after Harvey turned himself in at Pannawonica police station, some 1500 kilometres north of Perth.

WA Police Commissioner Chris Dawson said Harvey had spent “some days” in the Coode Street house before making his way to the Pilbara town.

Mr Dawson said 23 people had died in domestic violence-related circumstances already this year.

“It’s impossible for me not to take stock that in the last four months, 15 people have lost their lives in three separate family tragedies,” Mr Dawson told reporters.

“It’s an absolute tragedy.

“Everyone is concerned about this – we have been for a long period of time.”

Mr Dawson described a statement issued by Mara’s sister Taryn on behalf of the family as heart-wrenching.

“There are no words to explain the emptiness and loss that we feeling,” she wrote.

She said Beverley would have done anything for her daughters and grandchildren.

Mara was also a great mum.

“She was so proud of each of them and was doing a great job of raising them,” Taryn wrote.

“Her girls were her world.”

Charlotte was described as an energetic and confident girl who loved socialising, while Alice was adventurous and cheeky, and the more quiet Beatrix gave “the biggest hugs”.

“This world is a sadder place with the loss of these five beautiful people but Heaven has gained five new angels.”

As the police forensic team scoured property for evidence, taking it away in brown paper bags, Bedford locals expressed their shock and disbelief.

One woman said: “I don’t know what’s coming to this world.”

An elderly man who has lived in the neighbourhood for decades said it was “normally a quiet place”.

A young father, who is building a house nearby, said: “I’ve got a two-year-old girl – I can’t rationalise anything that would cause someone to do that.”

A bouquet of red roses with a card saying “rest in peace, neighbours” has been placed near the house.