The bodies of Mr Harvey’s partner Mara, their children Charlotte, three, twins Alice and Beatrix, two, and Mara’s mother Beverley Quinn, 73, were found on Sunday 9 September.
Karratha Magistrates Court was told the children and Mara were killed on September 3, while Beverley was allegedly killed on September 4.
The named dates mean the family was dead inside their suburban Perth home for almost a week.
Mara has been described as a ‘beautiful person’ and a hardworking ‘go getter’.
In tributes posted to social media, old school friends of the 41-year-old mum expressed their shock at her death.
‘I am in shock. There are no words,’ wrote one friend.
‘I sat next to Mara in the same form class since yr 10. Lost for words… so sad,’ wrote another.
At a press conference on Sunday, Assistant Commissioner Paul Steel said the event had sent ‘a ripple through the community of Western Australia’.
‘This is a tragic event that will have no doubt have an impact, not only on the family and friends of the deceased, but for the whole of the community, those first responders who were faced with attending a scene with multiple deceased people,’ he said.
Anthony Harvey is due to appear in court again via video link on September 19.