A University of Hong Kong professor on trial for murder was a depressive victim of his wife’s chronic psychological abuse but had never thought of killing her, a court heard on Monday. Clinical psychologist Dr Sammy Cheng Kin-wing concluded that Cheung Kie-chung, 56, had “serious issues in emotional control” and was particularly vulnerable to losing it, especially when he had too much work to do and after he fell seriously ill with a blood infection in April 2018. But the main cause for his vulnerability was said to be his wife’s difficult personality and the “verbal violence” she allegedly inflicted upon him, to the extent of psychological abuse, which was found to have reached a moderate to serious degree. “I would say the defendant was a victim of chronic psychological abuse at home [by] the defendant’s wife,” Cheng told a High Court jury. “Because the verbal abuse lasted more than two years, it had an impact on the ability of the defendant’s emotional control.” Cheung has admitted killing his wife Tina Chan Wai-man, 53, and covering up her death until his arrest on August 28, 2018. But he has pleaded not guilty to murder and presented the defence of provocation and diminished responsibility, based on his depression, in a bid to reduce the charge to a lesser one of manslaughter, which is also punishable by life in prison. The psychologist, who had interviewed Cheung for 11 hours upon the defence’s request, further revealed that the defendant had told him “he never thought of killing his wife”, but confessed that he was very emotional – with a lot of anger, nervousness and anxiety – at the time of the incident on August 17, 2018. Dispute over orange juice sparked wife’s killing, professor tells court Senior assistant director of public prosecutions Jonathan Man Tak-ho asked: “Did the defendant tell you that at the time of killing he couldn’t control himself?” “He did not know why he had killed his wife,” Cheng replied. “He guessed that he might have problems in emotional control.” The expert also observed that Cheung did not know how to express himself and concluded he was “a person who suppressed his emotions all along” as a survival skill and response to psychological abuse, so his symptoms could not be fully reflected. He did not know why he had killed his wife. He guessed that he might have problems in emotional control Dr Sammy Cheng, clinical psychologist He added that he was not surprised that Cheung had forgotten the details of the killing, as clinical studies and experience show that it may be totally impossible for a person under extreme stress – with his emotions hijacking his rationality – to focus on what he was doing. “That’s why a person may not be able to recall the events at the time afterwards,” Cheng added. His evidence was supported by psychiatrist Dr Robyn Ho Mei-yee, also called by the defence, who concluded that Cheung was suffering at the time of the killing from major depressive disorder, which could cause him to lose control, have problems with his ability to think or make decisions, and substantially impair his mental responsibility. Ho said this depression could be the result of chronic stress brought by a high pressure job or a challenging relationship. Hong Kong professor, wife were ‘quite happy together’ before he killed her She observed that Cheung’s mental state deteriorated from 2013 – when his daughter Nancy returned from Britain – and worsened from around May 2018, as he complained of increased irritability, depressed mood and feeling increasingly worthless when his wife scolded him. She further concluded that Cheung had been suffering from depression for months in the lead up to the killing. “The defence of manslaughter on the basis of diminished responsibility should be available to him,” Ho said. “But it is for the jury to decide.” Cheung’s defence counsel Graham Harris SC and the leading prosecutor will present their closing speeches before Madam Justice Anthea Pang Po-kam on Tuesday.