Murder of Ho Hon Sing

On 3 August 1989, 34-year-old illegal moneylender Ho Hon Sing (何汉成 Hé Hànchéng) was found dead at the foot of a Housing and Development Board (HDB) block at Beach Road, Singapore. Initially thought to have committed suicide, he was later found to have been drugged and thrown off the flat's common corridor by his childhood friend, 37-year-old Yeo Watt Song (杨越松 Yáng Yuèsōng).

Police investigations
Initially, there were no signs of foul play at the crime scene, and Ho's death was ruled to be a suicide. However, investigations showed a few red flags. There was no clear reason for a suicide, and Ho's valuables were found to be missing. In addition, on the day after Ho's death, Ho's wife received a suspicious phone call, in which the caller said that "Ah Sing (referring to Ho) will not be sleeping at home tonight".

An autopsy showed that the cause of death was multiple injuries due to the fall, and his body contained traces of morphine. In November, after investigations showed that Ho's valuables, a gold chain, three gold rings and a Rolex watch, were missing, the police suspected murder and the Criminal Investigation Department’s Special Investigation Section took over the case. Ho's friends were interviewed. Yeo was arrested on 28 December, nearly five months after Ho's death.

Trial of Yeo Watt Song
On 26 November 1992, Yeo Watt Song stood trial for the murder of Ho Hon Sing, with Judge T. S. Sinnathuray presiding over the trial.

Trial hearing
Deputy Public Prosecutor Bala Reddy tendered Yeo's police statement as evidence. According to his police statement, on the night of 2 August 1989, Yeo and Ho were consuming drugs together. Yeo had noticed that Ho was wearing a gold chain, three gold rings and a Rolex watch. Ho had also shown him $6000 which he had collected from debtors. However when Yeo asked him for a loan of $1000, he was turned down. This made Yeo think of Ho as boastful, and he wanted to get revenge. As such, he hatched his plan to rob and kill Ho.

At about 2pm the next day, Yeo lured Ho into a block of flats in Beach Road on the pretext of getting some heroin there. Yeo asked Ho to wait for him near the lift, while he went to a coffee shop to buy a soft drink and spike it with the Upjohn tablets. They then took a lift up to the 13th storey of the flat, where Ho began to feel drowsy. Yeo removed Ho's valuables before looking for a chance to throw him off the building. As Yeo saw a woman on the corridor watering her plants, he brought Ho one storey down and carried out his plan.

The defence argued that as Yeo had consumed heroin that day, he was not aware of what had happened when he was with Ho after they went up to the fifteenth floor. They had initially gone up with the intention of purchasing drugs, but could not find the drug dealer. At this point, both of them became drowsy due to the drugs they had consumed earlier, and Yeo did not know what happened to Ho afterwards.

The defence sought the testimony of an expert witness, Associate Professor Edmund Lee Jon Deoon from the National University of Singapore's Pharmacology Department, about the effects of the Upjohn tablets. Associate Professor Lee testified that the tablets could have side effects of anxiety and hallucinations, which could have caused Yeo to push Ho off the building without being consciously aware of his actions.

The prosecution's expert witness, Dr Chan Khim Yew, head of the Prisons Medical Unit in Changi Prison, rebutted this argument. According to Dr Chan's testimony, he does not find it plausible that Yeo would be so intoxicated by the drugs that he was unaware of what he was doing. He felt that Yeo was able to tell right from wrong and was mentally capable of carrying out his murderous intent.

Verdict
On 3 December, Judge Sinnathuray concluded that the prosecution had proven that Yeo was guilty of murder, and sentenced Yeo to the mandatory death penalty.

In March 1994, Yeo Watt Song was hanged in Changi Prison.

In April 1995, Singaporean crime show Crimewatch re-enacted the Ho Hon Sing murder case and aired it on television.