Walking past a Geylang coffee shop, a former inmate saw someone he recognised - an ex-prisoner he had a grudge against for squealing on him while they were in jail.
Jamsari Yusof, 51, confronted the alleged snitch, 43-year-old Gunasekaran Rengasamy, accusing him of being a "hantu" - prison parlance for an informer.
Things got ugly when the three men who had been drinking with Mr Gunasekaran decided to turn against him. In the ensuing fight, Jamsari fatally stabbed Mr Gunasekaran with a knife handed to him by one of the drinking buddies.
Yesterday, Jamsari found himself back in jail for 12 years, after he pleaded guilty in the High Court to culpable homicide, for kicking, punching and stabbing Mr Gunasekaran in the early hours of Feb 13, 2012. Jamsari escaped caning because of his age.
Justice Chan Seng Onn said surveillance camera footage of the fight showed that he was "clearly the principal aggressor" in what appeared to be an act of revenge. The judge noted that he "viciously and mercilessly" stabbed the unarmed victim, who never retaliated.
Although defence counsel Mohamed Muzammil Mohamed said his client was drunk, the judge said that the attack was deliberate and that Jamsari's kicks did not miss their mark.
Jamsari, who had been in and out of jail mostly for drug offences, was last released in 2011.
When he saw Mr Gunasekaran at the coffee shop some months later, he became enraged because he suspected that the victim had complained to prison officers about him.
Despite Mr Gunasekaran's denials, Jamsari started assaulting him. Two of the victim's drinking buddies, Terrence Goh and Redzuan Pupon, joined in.
A third, Kung Kwai Cheong, took a knife from his bag and passed it to Jamsari, who stabbed Mr Gunasekaran's face, neck and chest with it.
Jamsari was acquainted with the trio - Goh through prison and the other two from coffee shops in Geylang. The victim was found at 2.20am by police officers on patrol. He died in hospital hours later.
Last year, Goh and Redzuan were each jailed 15 months for causing hurt, while Kung was jailed four years for abetting in causing hurt with a dangerous weapon.