A Malaysian professor who was having an affair filled a yoga ball with dangerous gas to kill his wife and daughter in a “deliberate and calculated” murder plot, a Hong Kong court heard on Wednesday.
Khaw Kim-sun, 53, a specialist in anaesthesiology, put the inflatable ball containing carbon monoxide in the boot of a yellow Mini Cooper driven by his wife, Wong Siew-fung, 47, on May 22, 2015, prosecutors told the High Court.
His 16-year-old daughter Khaw Li-ling was in the passenger seat.
Prosecutor Andrew Bruce SC told the jury of five men and four women that Khaw set up a research project with “no value” to obtain the carbon monoxide he later used in the murder plot and was assisted in this project by the student he was having an affair with.
His colleagues at Chinese University’s department of anaesthesia and intensive care spotted Khaw filling two yoga balls with carbon monoxide. He claimed he wanted to test its purity and also told them he was experimenting with the effects of the gas on rabbits.
But experts said Khaw’s rabbit experiment would not be transferable to humans and that it was “extremely dangerous” to store such gas with yoga balls.
Bruce said Khaw knew the risk and put a meter in his car when he took two yoga balls, filled with carbon monoxide, home. Invoices showed he spent tens of thousands of dollars on 6.8 cubic metres of carbon monoxide of 99 per cent purity.
During police interviews, Khaw said he had taken the gas home in the yoga balls to exterminate rats at home, but a domestic helper who worked for him said there had never been a rodent problem.
Khaw also suggested his daughter might have used the gas-filled balls to commit suicide, something which Bruce called “a lame lie”.
“It is simply not true,” he said, adding that teachers at her school had said she was happy. Khaw’s wife knew about his mistress, but refused to get a divorce, Bruce said.
The court heard Khaw’s wife and daughter were found in a car parked at the Sai O Village bus stop in Ma On Shan by a jogger.
Tong Yuk-ling told the court she initially thought the pair were taking a nap, but grew suspicious when she came past a second time, 45 minutes later, and noticed the wipers were on even though it had not rained.
They were taken to the Prince of Wales Hospital in Sha Tin, where Khaw also worked as a doctor, where they were certified dead.
A postmortem found they had died from inhaling carbon monoxide, but the car showed no defects, which led officers to shift their attention to a deflated yoga ball in the back of the vehicle.
The prosecution said Khaw probably did not intend to kill his daughter.
“The last thing the accused wanted was for his 16-year-old to die,” Bruce said. Khaw had not been aware his daughter was away from school on the same day he planned to kill his wife.
“[But] if that person knew what was in the car was carbon monoxide and knew it was a dangerous gas likely to kill you, you can confirm this person had homicide on his mind,” Bruce told the jury.
He said the gas, while present in everyday life, could impair vision and cause unconsciousness and death, if inhaled in sufficient volume.
“It can kill,” Bruce said. “And it did kill.”
Khaw has pleaded not guilty to two counts of murder and the trial continues on Thursday before Mrs Justice Judianna Barnes Wai-ling.
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