An autistic Mt Hawthorn man killed his mother to plunder her finances and concocted elaborate lies to cover up her death, a Supreme Court judge said today as he found him guilty of her murder.
Brent Donald Mack, 27, made no reaction as he was convicted this morning over the death of his mother Ah Bee “Pauline” Mack, who disappeared in December 2008, following a judge-alone Supreme Court trial earlier this month.
In an entirely circumstantial case, prosecutors argued Mack killed his shy, reclusive mother to gain control of her property and money, with $225,000 of her funds moved to his account after her death.
In a decision published today, Justice John McKechnie rejected Mack’s claims that he found his 56-year-old mother trying to kill herself in the shower, describing it as an “inexplicable and unbelievable” lie.
“I find it so bizarre precisely because it was made up,” he said.
“I reach the degree of satisfaction beyond reasonable doubt by virtue of his motive for her killing, his conduct in the use of her bank account to steal a large amount of money for his own purposes, his repeated lies... that he disposed of the body in the dark of night by burying it in a grave which he had dug, adding lime to the grave to hasten decomposition.”
Justice McKechnie said he was satisfied Mrs Mack was dead by December 29, 2008 when her son “first delved into her bank account”, finding “he killed his mother and plundered her finances for his own purposes”.
In recorded police interviews shown during the trial, Mack claimed he left his mother in the shower for a week before disposing of her body at the Lake Gewlup wetlands.
In the video, he said he felt “sentimental” about his mother’s death and chose the site because it was “quite nice”, private and “maybe” because it would help her decompose and “become part of the wetland quicker”.
Her body has never been found.
Justice McKechnie said Mack went to elaborate lengths, including forging his mother’s signature and fabricating a greeting card from her, to convince friends and relatives she was still alive.
“The accused consistently and consciously told lies to divert attention from his crime because he knew he could not tell the truth and remain unpunished,” he said.
“He did so to cover up his crime of murder, not just a homicide.”
Mack was remanded in custody ahead of sentencing in January.