Father of three Anthony Robert Harvey, 25, who was married for three years to 41-year-old Mara Lee Harvey. They met at a mine site but at the time of the killings she worked in a supermarket and he ran a Perth lawn-mowing franchise.

THE VICTIMS:

Ms Harvey, two-year-old twins Alice and Beatrix, three-year-old Charlotte and 73-year-old grandmother Beverley Ann Quinn

WHAT HAPPENED:

The family was repeatedly stabbed with newly-purchased knives at their Bedford home on September 3, 2018 and the grandmother was murdered when she visited the next morning. Harvey stayed in the house for days, then travelled about 1500km north to the Pilbara town of Pannawonica where he turned himself in

WHAT HARVEY SAID:

He was not angry with his family and had a good marriage. But he was obsessed with serial killers and had written in a journal about embracing his "darkness and animal instincts" and "eliminating" his family

WHAT THE PROSECUTION SAID:

The killings were so degrading and abhorrent Harvey should never have hope of freedom

WHAT THE DEFENCE SAID:

Harvey was young and remorseful and a minimum prison term should be set

WHAT JUSTICE STEPHEN HALL SAID:

"There is no other case that is truly comparable. Your actions were so far beyond the bounds of acceptable human conduct that they would instil horror and revulsion into even the most hardened of people."

THE SENTENCE:

Life in prison with an order that he never be released

WHAT FAMILY MEMBER TARYN TOTTMAN SAID:

"Please remember my mum Beverley as a generous, committed, loving mum and friend that she was; my sister Mara for her love, support and determination; my nieces Charlotte, for her enthusiasm and laughter, Alice, for her sense of adventure and cheekiness, and Beatrix, for her spirit and of course her hugs."

WHAT POLICE MINISTER MICHELLE ROBERTS SAID:

"They were the most horrific murders ... they were a shock to the community ... I think he's given up his right to freedom."

Australian Associated Press