David Reid sentencing hearing after parents Graham and Diana stabbed to death in Sydney home

David Reid woke up to go to work and then stabbed his parents to death at their Sydney home. But he didn’t mean to do it.

David Reid was charged after Graham and Diana’s deaths in Sutherland.

David Reid did not plan to kill his elderly parents but stabbed them to death – without warning or provocation – after dressing for work one morning in the south Sydney home where the trio lived, a court heard.

The 46-year-old IT worker then attempted suicide.

When he couldn’t do that, he rang triple 000 and gave a description of the scene to police.

The shock revelation emerged during Reid’s sentencing hearing for two counts of manslaughter, downgraded from murder charges, after a plea deal was reached negating the need for a trial.

“There was no planning whatsoever. He just got up in the morning and killed his parents, it’s quite frightening really,” Deputy Senior Crown Prosecutor Mark Hobart SC told the court.

“His mother was having breakfast. His father was asleep in the bedroom. He got up, got dressed to go to work, went into the kitchen to stab his mother, then went into the bedroom where his father was sleeping to stab him.”

When Reid was later questioned about his thought processes during his father’s attack, he allegedly said he was thinking: ‘I’ve begun this. I’ve got to finish it.”

The court heard Reid suffered from a severe undiagnosed mental illness but had never displayed any signs of violence or aggression.

“The act was entirely unpredictable, unforeseeable and utterly out of character,” defence barrister James Glissan SC told the court.

“Mr Reid, throughout his life at work was passive, non-violent and in no way aggressive to anyone. That is also entirely supported by every member of his family. His uncle described his as “not even assertive”.

Graham and Diana Reid, who were tragically found dead in their Sutherland home in August 2019. Picture: Supplied (Jannali Anglican Church)

In the aftermath of the killings, Reid made a series of quizzical statements, emblematic of his deranged state of mind.

“I thought I had a good relationship with my parents, obviously I don’t,” he is reported to have told police in the direct aftermath of the killings.

Taken to hospital for treatment of injuries to his arm and torso, sustained during the attack, Reid was asked for his next of kin by medical staff.

“The person he nominates is the mother he’s just killed,” Glissan SC told the court.

Despite assessment by more than three emeritus mental health professionals, psychiatrists Dr Adam Martin and Dr Stephen Allnut and neuropsychologist Dr Susan Pulman, experts were unable to determine any definite diagnosis to explain the bizarre attack. Suggestions were made he could be suffering from schizophrenia, autism and major depressive disorder.

However all agreed severe mental illness was a factor and that his presentation was decidedly “odd” including speech delays and an inability to understand his own actions.

“He had difficulty articulating … he can’t explain it,” Dr Allnut said.

A series of electronic diary entries tendered to the court showed Reid’s dark state of mind and intentions of suicide in the lead-up to the attacks.

In one entry he wrote:

“The reasons for not committing suicide are because it hurts the people who love you … this reason doesn’t apply to me because nobody loves me”.

The sentencing hearing continues.

Anyone who may be feeling distressed can contact Lifeline on 131 114, SANE Helpline on 1800 18 72 63 or Beyond Blue on 1300 22 4636.

Originally published as David Reid sentencing hearing after parents Graham and Diana stabbed to death in Sydney home