Brent Mack loses appeal against conviction and sentence for murdering his mother Ah Bee (Pauline) Mack, who was murdered by her son Brent. AN autistic Perth man who was jailed for murdering his mother has lost an appeal against his sentence and conviction. A Supreme Court judge found Brent Donald Mack guilty of murdering Ah Bee Mack in December 2008 and sentenced him to life in prison with a minimum of 20 years. Ms Mack, 56, who also went by the name of Pauline, was last seen alive in September 2008. Her body has never been found. Mack had claimed during the trial that his mother committed suicide, but prosecutors alleged Mack killed his mother for her money and property. An appeal was lodged against Mack's conviction and sentence, claiming the judge erred in concluding he was fit to stand trial, and then gave him a sentence that was manifestly excessive. But the Court of Appeal on Monday said there was no evidence to suggest Mack's autism prevented him from understanding court proceedings and there was no miscarriage of justice. "There is no doubt that the appellant is intelligent," Justice Michael Buss said. He added that the sentence was reasonable and just. Leave to appeal the conviction on three other grounds - including that Mack's lies did not indicate a consciousness of guilt, but rather, were explained by the communication and perception difficulties he had due to his autism - were not granted because the court ruled they did not have reasonable prospects of success. Originally published as Man loses appeal against mum's murder