Although he appeared in family photos as a loving father, he in fact harboured resentment towards his small daughters.
He wrote in diaries about wanting to 'eliminate' his family, which Justice Stephen Hall found to be proof the killings were planned.
The children were attacked as they slept.
'This is the place they should have been safest,' Justice Hall said. 'They should have been able to trust their father to protect them.'
Sentencing Harvey to life in prison with no chance of ever being released, Justice Hall said the case was not 'truly comparable' with any others.
'Your actions were so far beyond the bounds...they would instill horror and revulsion in the most hardened of people,' he told Harvey.
The lawn-mower service franchisee is the first person in Western Australia to be sentenced to die behind bars.