On 29 December 1971, the Gold Bars triple murders occurred when Ngo Cheng Poh (), a 55-year-old businessman and gold bar smuggler, was murdered by a group of ten men alongside his employees, 57-year-old Ang Boon Chai () and 51-year-old Leong Chin Woo (). The group also robbed the three men of 120 gold bars worth S$500,000. The robbery-murder was masterminded by 31-year-old Andrew Chou Hock Guan (), an air cargo supervisor who had been a middleman for Ngo's smuggling of gold onto flights from Singapore to Vietnam. He decided to commit the robbery due to an event that deteriorated Chou's ties to gold bar syndicates.
After a trial lasting 40 days, Andrew Chou, his 34-year-old brother David Chou Hock Heng (), and five out of the remaining eight perpetrators were sentenced to death for murdering the three gold smugglers. The remaining three were placed under indefinite detention; two of them were minors at the time of the offence while the other became the prosecution's chief witness. After losing their appeals, the seven condemned were hanged on 28 February 1975.
Murder investigation On 30 December 1971, while conducting training inside a jungle in Bedok, several National Servicemen discovered three dead bodies, all of whom were male. The bodies were found to have cloth wrapped around them, and green nylon rope was tied around their necks and limbs. After the start of investigations, the police were able to ascertain the identities of the men, having traced back to a missing persons report made by the wife of one. One of them was identified as Ngo Cheng Poh, a 55-year-old import-export company owner. Ngo, who was originally from Hong Kong before immigrating to Singapore, had a wife and five children at death. The remaining two victims were Ngo's employees: 57-year-old Ang Boon Chai and 51-year-old Leong Chin Woo. Leong had a wife, four sons and one daughter, while Ang had a wife and four children. The police later discovered two abandoned cars which belonged to the victims. Forensic pathologist Chao Tzee Cheng determined that the cause of death was strangulation, and also that the three victims were assaulted prior to their deaths. He also deduced that the three men had died between 30 and 36 hours before their bodies were discovered.
Goh Cheng Hong, Ngo's widow, told the police that her husband traded in gold and was supposed to drop by a business partner's house on the night of 29 December 1971 to deliver 120 gold bars to them. The partner was 31-year-old air cargo supervisor Andrew Chou Hock Guan. She also told the police that Chou had called her on the night itself, saying that Ngo did not arrive at his house as agreed upon. Goh subsequently accompanied Leong's wife in filing a police report that reported their husbands missing. The report was filed two hours prior to the discovery of the bodies.
The police approached Andrew Chou and his 34-year-old brother, David Chou Hock Heng, who was a university graduate working at a pharmaceutical company, and questioned them. They noticed that Andrew's right hand was bandaged while David had several scratch marks on his chest. Andrew stated that the injuries were the result of an overly rough karate practice. The next day, the police inspected the house of the Chou brothers, where they lived with their mother, sister and David's two daughters (he was divorced at the time). Several bloodstains were found at the front yard of the house, and the green rope used to hang clothes outside the house was found to match the rope around the necks of the three victims.
The Chou brothers confessed that they were responsible for a gold bar robbery that killed Ngo and his associates, while stating that another eight people were also involved. Following the revelation, the remaining eight accomplices were arrested. Two of them were Andrew Chou's friends: 24-year-old clerk Peter Lim Swee Guan () and 25-year-old Augustine Ang Cheng Siong (), who were both involved in planning the robbery-murder alongside the Chou brothers. The remaining six accomplices arrested were youths hired by the four. The six youths were identified as 20-year-old Stephen Francis, 19-year-old Alex Yau Hean Thye (), 18-year-old Konesekaram Nagalingam, 18-year-old Richard James, 16-year-old Stephen Lee Hock Khoon () and 16-year-old Ringo Lee Chiew Chwee (). Subsequently, all the ten suspects were charged with three counts of murdering Ngo, Ang and Leong.
The police also managed to recover all the 120 gold bars several days after the murders. Five of the gold bars were found inside David Chou's office in his workplace, while the remaining 115 gold bars, packed in bundles of five, were found in the home of Lim's aunt, Catherine Ang, who was supposed to help sell them. These gold bars, which were confiscated by the police, reportedly had a net worth of S$500,000.
Trial Augustine Ang's discharge and detention without trial On 10 October 1972, the Gold Bars triple murder trial took place at the High Court, with two veteran judges—Justice Choor Singh and Justice Frederick Arthur Chua—presiding over the trial. However, Ang did not stand trial, as he had been granted a discharge not amounting to an acquittal and indefinitely detained without trial under the Criminal Law (Temporary Provisions) Act. His discharge without trial was attributed to his confession to having taken part in the murders and the sustained consistency of his testimony; he also became the prosecution's chief witness against his nine accomplices, who all pleaded not guilty to the three counts of murder.
Prosecution's case The trial court heard that in early 1971, Andrew Chou, then an air cargo supervisor at Air Vietnam, began to act as a middleman for several gold bar syndicates and transport gold bars from Singapore to Vietnam through Vietnamese flights departing from Singapore; Ngo belonged to one such syndicate. The syndicate members would often drop the gold bars at Chou's home in Upper Serangoon, and he would assist them in evading security while they smuggled the gold onto said flights. In return, Chou would receive a total of US$15 per one-kilogram gold bar each from both the foreign and local smuggling superiors. He performed the routine two to three times weekly for several months. However, in October 1971, the relationship between Chou and the syndicates began to deteriorate when a bag that contained about US$235,000 in cash was lost at the airport after arriving on an Air Vietnam flight. Chou had been in charge of collecting the bag of money, and recovered about US$180,000 from airport staff under threat from the syndicates. However, the rest of the money was never recovered, and Chou's income from gold smuggling was considerably reduced as he had lost the syndicates' trust.
The prosecution, led by Solicitor-General Abdul Wahab Ghows and Senior State Counsel S. Rajendran, alleged that Andrew Chou was the mastermind who planned and arranged for the robbery-murder plot over the syndicates' loss of trust in him. David Chou, Ang and Lim were alleged to be primary subordinates who assisted him in planning the crime and recruiting several youths to kill Ngo and his associates at the next arranged delivery of smuggled gold.
Francis, James, Konesekaram and Ringo Lee were not involved at the beginning of the robbery-murder plot. Andrew Chou and the primary subordinates had initially gathered a batch of five youths to assist in murdering the victims. They included Alex Yau, Stephen Lee and three other youths—Fernando Lee Beng Hong, Ringo's elder brother, Soh Ah Seng and a third boy known only as "Anchor". However, the latter three backed out of the plan, leading to the four participants entering the plot.
Ang's testimony From this point on, the prosecution's case relied on Ang's evidence; he took the stand on the tenth day of the Gold Bars triple murder trial. He testified that he, together with the Chou brothers and Peter Lim, first started to plan the robbery in November 1971. Lim was in charge of recruiting youths to assist them in robbing and murdering Ngo and his associates, and Ang himself was to instruct the six boys—Konesekaram, Stephen Lee, Ringo Lee, Francis, James and Yau—about their plan to rob and murder the three victims, promising each of them S$20,000 as a reward. Ang also recounted that on the night of 29 December 1971, after ensuring that the mother and sister of the Chou brothers, as well as David's two daughters, were fully asleep, the ten perpetrators gathered at the Chou family home to wait for Ngo's arrival. After the arrival of Ngo and his two associates Ang Boon Chai and Leong Chin Woo, Ngo and Leong alighted their respective vehicles and passed Andrew Chou a bag containing 120 gold bars. After receiving the bag, the ten men began to attack the three victims. Ang stated that he pinned down Ngo's legs while the latter was being strangled by Andrew Chou, and also witnessed David Chou using the green rope to strangle Leong. Ang Boon Chai was the last victim to be assaulted; Augustine Ang said that, after seeing that Andrew Chou had inflicted several punches and karate chops onto Ang Boon Chai's neck and head, he picked up a wooden block to carry out repeated beatings until Ang Boon Chai fell unconscious.
After killing the three men (who all died from strangulation), the ten men covered the bodies; coincidentally, two of the Chou family's neighbours, a married couple, had just arrived home from watching a movie. To escape suspicion, David Chou went to greet the couple and ensure that they had not seen the aftermath of the murder, and Andrew Chou pretended that he was drunk and talking to the other eight men, who were standing around the bodies to prevent the couple's detection. Later, while Ang and the Chou brothers stayed behind to clean up the crime scene, the other accomplices helped to transport the bodies to a disused well in Changi; however, the boys left the bodies in thick bushes beside an old mining pond in Lembah Bedok. The two cars belonging to Ngo and Leong were also abandoned by the killers.
After completing his testimony on the stand, Ang was cross-examined on the stand by the nine accused's six defence counsels: Giam Chin Toon (David Chou's lawyer), Wong Peng Khoon (Andrew Chou's lawyer), N. C. Goho (who represented Francis, James and Konesekaram), Leo Fernando (Yau's lawyer), John Tan Chor-Yong (who defended Ringo Lee and Stephen Lee) and G. Gopalan (Lim's lawyer). During the 33-hour long cross-examination of Ang, they sought to question his credibility as the prosecution's key witness, and tried to present him as an unreliable witness willing to save himself by betraying his accomplices. Ang, who admitted that he had joined the robbery in order to get rich, conceded on the stand that he did accept the prosecution's offer to turn state evidence against his accomplices out of a desperation to avoid the death penalty, while denying that he would lie to save himself. He also stated that he was fully aware of the indefinite detention resulting from the deal and that the discharge included did not amount to an acquittal or pardon. When the lawyers representing the Chou brothers attempted to assert that Ang was the true mastermind who initially suggested the robbery-murder, the key basis of their defence, Ang denied that account as well. He spent ten days taking the stand, including his testimony and cross-examination.
Defence