Gregory John William Quartermaine’s lawyer argues for manslaughter, not murder in horror Tambellup killing

Tambellup man Gregory John William Quartermaine will learn his fate next week when Supreme Court Justice Stephen Hall delivers his verdict on the alleged murder that rocked his home town. Mr Quartermaine, 42, is alleged to have decapitated and dismembered 60-year-old family friend Wilfred Williams at a house on Garrity Street in Tambellup about midnight on August 4, while other people — including children — were inside. Defence counsel Bruno Illari is not contesting that his client killed Mr Williams, but is arguing he should be found guilty of manslaughter, not murder. In his closing statement on Tuesday at the Albany Supreme Court, Mr Illari said his client could not form the intent to commit murder because he was in a state of drug-induced psychosis. He said Mr Quartermaine could not control his actions on August 4 and was acting under delusion, rather than intent to murder. However State prosecutor David Davidson said the accused’s previous drug-induced mental health episodes showed he had the capacity to form intent to cause injury or kill in such a state. During day six of the trial on Monday, Mr Quartermaine’s history of drug-induced psychotic mental health episodes was in the spotlight as the prosecution spent hours questioning his psychiatrist, Dr Victoria Pascu. On March 3, 2015, Mr Quartermaine tried to take his own life because of “drug-induced psychotic” symptoms, Dr Pascu told the court on Monday. On June 24, 2018, Mr Quartermaine was admitted to Katanning hospital because he was having difficulty recovering from another methamphetamine-fuelled psychotic episode, Dr Pascu said. Dr Pascu told the court Mr Quartermaine admitted to using meth the previous day and said he had received commands from a “devil entity” to kill himself and others. Dr Pascu said Mr Quartermaine did not suffer from an underlying psychotic illness but experienced states of “drug-induced psychosis”. She said Mr Quartermaine had a long history of substance abuse and had developed psychosis because of meth use, which could cause “auditory hallucinations”. Dr Pascu said she believed his state of psychosis affected his capacity to form an intent to injure or kill. Mr Quartermaine had meth, amphetamine and cannabis in his system 14 hours after the alleged murder. The court was also shown footage of a police interview conducted on August 4 last year, when he told homicide detectives an evil person — such as the “devil”, “Satan” or “black magic man” — had given him instructions to kill. When a detective asked him if the devil made him kill Mr Williams, he replied: “Of course he did. The devil comes to me all the time.” “His purpose was to hurt (Mr Williams) based on a psychotic reality that if he didn’t do it, his family would be hurt ... he knew what he was doing within his reality,” Dr Pascu said on Monday. Mr Illari said his client “wasn’t able to exercise willpower to stop what he did”. Mr Davidson said Mr Quartermaine had experienced previous episodes of drug-induced psychosis in which he refrained from injuring or killing people. However, Dr Pascu said refraining from carrying out acts previously did not mean Mr Quartermaine would “maintain that restraint until the end of his life”. The combination of meth and cannabis use increased the severity of his psychotic episode on August 4, she said. Justice Hall is set to deliver his verdict on Friday, December 11.