He had just got home after a 12-hour shift when he was told that police cars had been overturned in Little India.
Assistant Superintendent Roy Lim of the Special Investigation Section (SIS) grabbed some clothes then headed back to Cantonment Police Complex and took a police car to the scene.
Barely 14 hours after he was tasked with overseeing the investigation of last month's riot, ASP Lim found himself gathering evidence in a Yishun flat where a 62- year-old woman had been murdered. Three days later, the mystery death of a decapitated woman was waiting to be solved.
There is no typical workday for the 42-year-old detective from the Criminal Investigation Department (CID). Earlier this month, he helped to nab the two suspects involved in the kidnap of the Sheng Siong supermarket chief's mother. It led to 39 officers, two police departments and four units being honoured with the Minister for Home Affairs Operational Excellence Award.
Murders do not always occur during business hours and ASP Lim is on call round the clock - even if it means him setting up a safari bed next to his desk.
In an exclusive interview with The Straits Times, ASP Lim said it is often through closed-circuit television (CCTV) as well as extensive groundwork and intelligence work that perpetrators are nailed.
In the recent case of the decapitated woman's body found in Whampoa River, police were able to identify the murder suspects even before establishing the victim's identity. ASP Lim declined to go into details but praised advancements in technology.
"In the past, we needed to send our DNA samples overseas for testing and it could take months to get the results," he said. "Today we have our own facility and it takes half the time."
ASP Lim said technology also played a part in helping him nail the murderer of 22-year-old Chinese national Liu Hong Mei in a high profile case in 2005.
Ms Liu's upper torso and lower body were found wrapped in plastic bags in cardboard boxes on the banks of Kallang River. Her killer, factory supervisor Leong Siew Chor, 52, was captured on CCTV withdrawing cash from an ATM after ASP Lim and his team of investigators spent days going through footage. Leong was hanged for the crime in 2007. "You can't fast forward, you will miss details," said ASP Lim. "After he withdrew the money, I wanted to find out where he went. I had to get CCTV footage from the whole stretch and start watching to find the person who fit his description."
ASP Lim tries to approach investigations logically. When he arrives at a crime scene, he puts himself in the killer's shoes and goes through the motions he would have gone through - like where he was standing, what he would have picked up and how he would have fled.
In his 14 years with CID, ASP Lim said he has never let feelings rule his work - even when he was overwhelmed with "disbelief and anger" when he found out the suspect in the Kovan double-murder case was one of his own officers.
"It was very difficult for us when we first found out," he recalled.
ASP Lim informed the various immigration checkpoints and sought assistance from the Royal Malaysian Police. Iskandar Rahmat, 34, who is accused of killing car workshop owner Tan Boon Sin, 66, and his 42-year-old son, was eventually arrested in Johor after a 54-hour manhunt.
Although ASP Lim is a fan of the Crime and Investigation channel, his work is not always that glamorous. During the investigation of the two major train breakdowns in 2011, ASP Lim had to walk through the train tunnel between the affected stations more than 10 times to search for clues.
He also had to sieve through five tonnes of rubbish at Tuas South incineration plant to search for the decapitated woman's missing body parts and sniff for clues - after learning to differentiate the smell of rubbish from that of a decomposed body.
It's a long way from the young recruit who first saw a decomposed body during his time with the Police Coast Guard in 1991. "After that I never touched prata with curry for a while," he said.