[1] Thabun's killer, 29-year-old Tan Chee Wee (陈志伟 Chén Zhìweǐ), who was a Malaysian and an assistant store supervisor, was arrested the next day after he committed the brutal crime.
As Ler entered the flat and went inside the master bedroom, he discovered his wife lying dead in a pool of blood, clad in only her underwear and shirt.
During police investigations, it was found that a golden Rolex watch, some gold accessories belonging to Thabun, and cash amounting to around S$500 to S$600 were missing from the flat.
Dr Gilbert Lau, a forensic pathologist, examined the body and found head injuries and a stab wound to the neck on the victim.
One of these mahjong partners, 29-year-old Tan Chee Wee, was found to have called the flat earlier on the morning of the date when Thabun was killed, based on the phone records retrieved by the police.
Although Tan denied going to the flat on that same day and insisted he was on sick leave, he eventually admitted to killing Thabun during a robbery, and he was thus placed under official arrest six hours after the investigations started.
[20] Justice Woo Bih Li of the High Court presided over the hearing while the prosecution was led by Deputy Public Prosecutor (DPP) Hay Hung Chun of the Attorney-General's Chambers (AGC).
Not only that, Tan was also heavily in debt as a result of gambling on football matches and at mahjong, and even borrowed money from moneylenders, friends and his colleagues.
Tan stated that on 9 January 2003, the same day he murdered Thabun, after he made his trip to the clinic, he decided to go to his gambling partner Ler Lee Mong's Chai Chee flat to commit armed robbery,[26] a plan which he formulated the day before in order to solve his financial problem, and even prepared several tools (including a spanner, a pair of gloves, a hammer and a screwdriver).
After forcibly bringing Thabun inside the master bedroom, Tan proceeded to rape the woman, who made another futile attempt to escape.
In his verdict, Justice Woo rejected Tan Chee Wee's contention that he had only hit Thabun once or twice on her head with the hammer without the intent to cause her death.
There was no basis for Tan to claim self-defence by using the hammer to hit Thabun after she disarmed him and gained possession of the knife, since he was the aggressor, and this was also not a sudden fight.