A dad who shot dead his son and daughter in a horrific murder suicide displayed a 'World's Greatest Daddy' shirt before turning the gun on himself.
John Edwards, 67, killed his daughter Jennifer Edwards, 13, and his son Jack, 15, in West Pennant Hills, Sydney's north-west, on July 5, 2018.
The children were later found 'crumpled together' under Jack's bedroom desk with multiple gunshot wounds.
Edwards killed himself at his rented home near Normanhurst on the night of the murders.
But before taking his own life, Edwards hung the black 'World's Greatest Daddy' shirt on a chest of drawers at the end of his bed, NCA NewsWire reported.
Jack (pictured left) and Jennifer's (pictured right) body were found under his bedroom desk with multiple gunshot wounds
Police officers found the display and Edwards' lifeless body sprawled across his bed.
'I believe this T-shirt had been strategically placed on the side of the chest of drawers so it could be seen when entering the bedroom,' Detective Sergeant Tara Phillips wrote in her statement.
Six months after the murder suicide, the children's mother Olga took her own life.
An inquest into the deaths began on Monday and the NSW Coroners Court heard Edwards had 'a propensity for domestic violence', including physical and psychological assaults against the women of his life and his many children.
One ex-partner said he was never physically violent but 'controlling' while another said he was 'unbalanced and a narcissist', the lead investigator told the inquest.
Including the two he murdered, Edwards had 10 children to seven partners.
Edwards (pictured) killed himself at his rented home near Normanhurst on the night of the murders. But before taking his own life, Edwards hung the black 'World's Greatest Daddy' shirt on a chest of drawers at the end of his bed
Edwards was awarded licences to shoot rifles and pistols in June 2017 after NSW Firearms Registry staff used a police database report that had failed to pick up several matters related to domestic violence.
Over the next year, he legally acquired five weapons including the Glock 17A 9mm semi-automatic pistol he used to shoot dead Jennifer and Jack.
Edwards hired a car and stalked his daughter on her way home from school in order to learn their new address before he