London - A scientist who battered his ex-wife to death in what he believed was the perfect murder was trapped by his satnav, a UK court was told on Monday.
Wai Tsang, 33, was involved in a custody battle with Mingzi Yang, 29, and wanted her dead so that he would not have to share access to their son Lucas, five.
He began planning her death immediately after he received a solicitor’s letter telling him she was seeking increased time with the boy.
Tsang, a chemistry graduate who worked as an industrial hygienist, created what he believed was a cast iron alibi putting himself 64km away from the scene of the killing in Lincoln.
Police instead arrested Miss Yang’s fiance Darren Grundy, 32, who found her body after calling at her terrace home in the city when she failed to answer his phone calls.
Mr Grundy was held for three days and questioned about the murder while Tsang remained free, giving police a detailed witness statement setting out his movements on the day of the killing.
He had switched off his mobile phone during the crucial period so that his true whereabouts could not be tracked.
BUT GPS DOESN’T LIE
What he had not reckoned with was that the satnav in his Mazda estate car had recorded his every move. It showed that instead of driving directly from his home in Grimsby to go mountain biking in Sherwood Forest, as he claimed, he had travelled via Lincoln and left his car in a secluded layby outside the city for two-and-a-half hours.
He then cycled to his ex-wife’s home, lay in wait for her to return from the morning school run and battered her to death. The court heard she had been ‘struck repeatedly and with force’, causing brain damage which killed her. He attempted to make it look as if a burlgary had taken place.
Detectives trawled through 3000 hours of CCTV footage from across the city to find images of Tsang cycling to and from the murder scene wearing a distinctive blue helmet.
Forensic tests on the bicycle and his watch revealed traces of his ex-wife’s blood. Officers arrested Tsang and freed Mr Grundy.
Tsang, who is British and of Chinese origin, of Scartho, Grimsby, denied murdering Miss Yang on June 17 but was found guilty by a jury at Lincoln Crown Court at the end of a month-long trial. Peter Joyce, QC, prosecuting, said: “Mingzi was killed for a reason. The only person who had a reason and a motive to kill her was him. This wasn’t a random killing.”
SEEMED LIKE A STRONG ALIBI
Mr Joyce said that after the killing Tsang went on to Sherwood Forest, buying a parking ticket and obtaining a timed receipt at a cafe to back up his alibi.
When police told him of Miss Yang’s death, he gave a lengthy statement detailing how he had set off from home between 7am and 8am and drove straight to Sherwood Forest, where he went biking. He said he later visited the site cafe before driving home.
But he slipped up when he agreed to hand his satnav to police. The subsequent check of the device revealed that Tsang had actually set off around 6am and travelled via Lincoln, stopping for two-and-a-half hours in the layby.
Then a witness came forward to say he had seen a cyclist matching Tsang’s description loitering outside the scene of the murder, and Tsang was arrested.
Judge Michael Heath yesterday jailed him for life and ordered him to serve a minimum of 28 years.
The judge said: “You are a very intelligent and very clever man. When poor Darren Grundy, a wholly innocent man, was in custody for three days I have no doubt that you thought you had committed the perfect murder and got away with it.
“You are a cold, calculating individual and a liar but you didn’t fool the jury as you mendaciously attempted to explain away the constellation of compelling evidence that the prosecution produced.”
Daily Mail