A Hong Kong-based university anesthesiologist hatched a murder plot that to others might seem rather off the wall.
At first, investigators were baffled by the deaths of the wife and 16-year-old daughter of Professor Khaw Kim-sum on May 22, 2015. Then a post-mortem revealed they had died from inhaling a very high quantity of carbon monoxide.
Prosecutors said that the 53-year-old university professor used his medical skills to fill an inflatable yoga ball that he put in the trunk of his wife's car where it leaked the gas that killed Wong Siew-fung and daughter Lily, according to media reports of the trial.
On Wednesday, a jury in Hong Kong, now a special administrative region (SAR) of China, did not believe his story that it was a case of suicide and unanimously convicted him of two counts of murder.
Khaw, who received a life sentence, had reportedly told colleagues at the Chinese University of Hong Kong teaching hospital that he wanted to "test the purity" of the carbon monoxide and its effects on rabbits after he was caught filling two yoga balls with carbon monoxide.
He told prosecutors later that he actually wanted to use the gas to kill rats at home, though the evidence suggested that the family did not have a rodent problem.
It turned out that Khaw was having an affair with a university student and his marriage had fallen apart. He and his wife lived in the same house but were estranged, the court heard.
Suicide claim
The couple's maid gave evidence that Khaw and Wong had been sleeping in separate rooms since she had started working for the couple and their four children.
Prosecutors accused Malaysian-born Khaw of hatching the murder plot because of the affair.
The professor told police after his arrest that Lily knew about the dangerous gas in the yoga ball, and suggested she may have wanted to commit suicide.
According to the New York Times, defense lawyer Gerard McCoy tried to build a case by portraying Khaw as a loving father who had inadvertently driven his daughter to kill herself because of his high expectations for her academic achievement.
"The last thing" Khaw wanted was to kill his daughter, prosecutors told the court. It was suggested that he was unaware that the teenager was not at school on the afternoon of the murders.
Wong and Lily were found by the roadside in a locked yellow Mini Cooper and were certified dead at the same hospital where Khaw worked.
The professor shook his head and looked at his three other children sitting in court on hearing the verdict, broadcaster RTHK reported. One of them burst into tears.
"It is shocking that a highly educated and successful man would conjure up such a calculated method to get rid of his wife," presiding judge Justice Judianna Barnes Wai-ling told the defendant, according to the South China Morning Post.
