A mentally ill man who "callously" bludgeoned his elderly mother to death with a plank of wood in the backyard of their Woonona home, then actively sought to conceal it, has been sentenced to nine years behind bars.
Boutros Mouawad had been arguing with his 72-year-old mother Helen Mouawad about gambling on the evening of February 18 last year when he picked up a large piece of wood and hit her multiple times in the head and face.
He then covered her head with a plastic bag to stop the blood flow, left her body in the garden and went to the Bulli-Woonona RSL, then returned three hours later and hit his mother again to make sure she was dead.
He went back to the RSL, disposed of the bloodied plastic bag in a bin, then called the police and claimed his mother had fallen.
A post-mortem found Mrs Mouawad had succumb to blunt force trauma to the head but was unable to establish when she had died.
Mouawad was initially charged with murder but pleaded guilty to the lesser charge of manslaughter after prosecutors accepted while he had an intention to kill his mother, his capacity to control himself was substantially impaired by his bipolar disorder.
In court on Friday, Judge Chris O'Brien said the offence was a serious example of manslaughter, involving "a significant degree of violence and aggression".
"There were multiple blows by [Mouawad] to [his mother] with a weapon, being a large piece of wood," he said.
"It was not a single attack but a protracted one involving repeated strikes to the head of [Mrs Mouawad] on two separate occasions separated in time by approximately three hours.
"In my view, there is a callousness displayed by [Mouawad] wrapping [his mother's] head in a plastic bag and leaving her prone in the backyard of the family home, prior to his leaving to attend at the RSL club on the first occasion. "
He said Mouawad's actions when he came home from the RSL the first time - hitting his mother again in the head before hosing her body to remove the blood and removing the plastic bag with a view the disposing of it - showed he was seeking to "cover his tracks".
"His conduct throughout the entire incident was both purposeful and calculated," Judge O'Brien said.
"He understood the wrongfulness of what he had done and actively sought to conceal it."
However, he also accepted evidence from two eminent psychologists that had it not been for Mouawad's mental illness, the killing would not have happened.
He sentenced Mouawad to nine years' jail, with a non-parole period of six years.
Mouawad will be eligible to apply for parole in February 2025.