On 8 August 2000 in Singapore, a group of three men, who were armed with firearms with an intent to commit robbery, had robbed and killed a taxi driver in midst of a planned crime spree.

In the aftermath of Koh's murder, the robbers had committed yet another robbery and also shot and killed their next victim, 39-year-old Jahabar Sathick, an Indian moneychanger.

After he drove to Chestnut Avenue and reached a quiet, deserted forest area, the three men suddenly wielded a bayonet and two guns, and threatened Koh, who fearfully tried to plead for his life and offer to pay anything to the robbers, and told them he had a family to feed.

Coincidentally, on the morning of 9 August 2000, at Chestnut Avenue, when three young boys were cycling to school along that same road, one of the students accidentally discovered Koh’s corpse in the forest.

The first happened two months before in June 2000, when Ong Huay Dee was murdered by a Thai carpenter named Khwan-On Natthaphon during a robbery bid.

[4][5][6] Upon the report, Senior Station Inspector Zainal Abidin bin Ismail arrived at the scene with his group of officers, and a search was made in the nearby area.

The investigations on 10 August 2000 also led to the police to trace the last location of Koh Ngiap Yong’s taxi, which was found abandoned in a carpark in Bukit Batok.

[7] 18 days later, on 26 August 2000, the police received a report that a man was shot dead by two Malay men at an overhead bridge in Jalan Kukoh.

It was on 15 October 2000 that a team of Special Tactics and Rescue (Star) officers managed to apprehend Wan Kamil, Ibrahim and Rosli in three different locations in Singapore.

[13][14] After this, all three men - Wan Kamil, Rosli and Ibrahim - were charged with the murders of Koh Ngiap Yong and Jahabar Sathick on 18 October 2000.

Deputy Public Prosecutor Lawrence Ang and his two colleagues Toh Yung Cheong and April Phang from the Attorney-General’s Chambers were set to prosecute the three men for murder.

They also argued that the three men may not have the plan to kill Koh, but it became necessary to avoid any chances of being identified; they also carried weapons beforehand, suggesting that they knew that there would be violence expected in the course of the robbery.

With reference to the trio’s plans to rob the goldsmiths and money changers and Cisco officers (revealed by the three during the investigations) prior to murdering Koh, the prosecution argued that there was premeditation to commit robbery and use violence if necessary on the part of the three men.

[18] Wan Kamil also said that there was an agreement to target moneychangers and goldsmiths as their victims to rob, and they reach a consensus to steal a vehicle to use as their getaway car to escape once they commit each robbery out of their planned crime spree.

[22] From Ibrahim’s side of the story, he left his Filipino girlfriend’s flat that morning to meet up with Wan Kamil and Rosli, and they observed their surroundings for any unattended vehicles before settling on hailing Koh’s taxi for the purpose of robbing it for use.

[26] Rosli stated that Wan Kamil, whom he befriended in December 1999, had discussed with him and Ibrahim in early August 2000 to commit robbery, and he suggested robbing Cisco officers who were escorting cash that to be loaded to the POSB ATM machines near the entrance of West Mall in Bukit Batok.

They initially agreed to engage in a shootout with the officers and take the money, but due to the presence of too many people at the vicinity, the plan was aborted and hence he suggested stealing a vehicle as a getaway car, which led to the trio to eventually target Koh and his taxi.

On 5 September 2001, after hearing the case for 19 days, High Court judge M P H Rubin delivered his judgement, and ruled that all the three men should be sentenced to death for murder.

For both Wan Kamil and Ibrahim, Justice Rubin determined that they shared the common intention together with Rosli to commit robbery; for this, even if they were totally not involved in the stabbing of Koh or never planned for it, it should be inferred that the stabbing by Rosli was done in furtherance of their joint common intention to rob Koh and since they were armed beforehand, it should be inferred that there was a premeditation to use the guns or bayonet to cause hurt or death in the course of robbery.

Wan Kamil's denials were, in the eyes of the judge, attempts to distance himself from what Rosli deliberately did since he was the mastermind behind the crime spree, and his decision to bring the weapons along showed he or the others had plans to use them, which reflected their common intention.

His willful ignorance to the stabbing of Koh has also reflected his morally-lacking character and his lack of responsibility for his actions, which were principal to leading to the fatal outcome of the Chestnut Avenue taxi robbery.

For his appeal, Rosli argued through his lawyer that he should not be guilty of murder as he was forced and coerced into doing so under the directions of Wan Kamil and there was no intention to cause Koh's death, thereby repeating his defence raised in his trial in the High Court.

Ibrahim, meanwhile, insisted in his appeal that he only acted as driver and never knew that Rosli would kill Koh when he dragged the man into the bushes, which was also repetitive of the case put forward by his own defence counsel.

[37] A 2021 article from The Smart Local named the murder of Koh Ngiap Yong as one of the 9 most terrible crimes that brought shock to Singapore in the 2000s.