[1] The first was Seing Koo Wan (Chinese: 邢谷环; pinyin: Xíng Gǔhuán), a 58-year-old taxi driver who was found with several stab wounds on his body.

Despite a police appeal, Seing's killer(s) was never found and the case remained unsolved for eight months before another taxi driver, Teo Kim Hock (Chinese: 张金福; pinyin: Zhāng Jīnfú), was allegedly kidnapped by two men who demanded a ransom from his family.

[3][4] On 17 April 1992, at the deserted outskirts of Yishun, 58-year-old Seing Koo Wan was found dead inside his taxi, which was abandoned at the area itself.

[12][13] On 24 December 1992, eight months after the murder of Seing Koo Wan, while 28-year-old Teo Wee San was at home in Hougang, he received a phone call from someone demanding ransom from him.

[24] On 23 February 1994, both 22-year-old Junalis Lumat and 21-year-old Mohamad Ashiek Salleh stood trial at the High Court for the murder of 59-year-old Teo Kim Hock.

[25][26] It was revealed that both Mohamad and Junalis were in need of money and could not find a job, which was why they decided to rob taxi drivers, and even bought nylon rope, two pairs of gloves and a toy gun.

A government psychiatrist Chee Kuan Tse was also summoned to court by the prosecution to testify against Junalis, who added in his testimony that he was suffering from depression at the time of the crime.

[29] On 10 March 1994, Justice S. Rajendran rejected the defences of both Junalis Lumat and Mohamad Ashiek Salleh, and therefore found both of them guilty of murder, and both men were sentenced to death.

[34] Subsequently, both Mohamad and Junalis appealed to then President of Singapore Ong Teng Cheong for presidential clemency, which would allow them to commute their sentences to life imprisonment if successful.

On the same day itself, two more death row prisoners - 27-year-old Chan Hock Wai who trafficked 149g of heroin, and 37-year-old Phua Soy Boon who killed 50-year-old contractor Sim Ah Lek - were executed at the same timing.