A robbery plan built around privileged knowledge
The Court of Appeal recorded that Iskandar bin Rahmat was serving as an investigation officer with the Singapore Police Force while facing serious financial difficulties. Through his work, he had previously encountered a police report filed by Tan Boon Sin concerning money kept in a safe deposit box.
Iskandar devised a plan to make Tan believe that the safe deposit box was at risk and that police needed to place a camera inside it. On July 10, 2013, he met Tan, used the false police pretext and ultimately followed him home after Tan had withdrawn a large amount of cash from the box.
Tan Boon Sin and his son were both killed
Inside the Hillside Drive home, Tan Boon Sin was fatally attacked. His son, Tan Chee Heong, arrived during the incident and was also fatally attacked. Iskandar did not dispute that he had stabbed both men; at trial and on appeal, the central disputes concerned his intent and whether legal exceptions to murder applied.
The aftermath of the killings generated immediate public attention and a manhunt. Iskandar was arrested in Johor Bahru, Malaysia, after Singapore investigators identified him as the suspect.
The High Court rejected the defence account
Iskandar argued that he had intended only to steal the money and flee, and that violent confrontations developed unexpectedly. The High Court rejected his account and found that the circumstances and injuries demonstrated an intention to cause death.
On December 4, 2015, he was convicted on two counts of murder under section 300(a) of the Penal Code and sentenced to death on both counts.
The appeal was dismissed in 2017
Before the Court of Appeal, Iskandar argued that he lacked an intention to cause death and relied on exceptions including private defence, sudden fight and diminished responsibility. The court considered fresh medical evidence but found no basis to disturb the murder convictions.
On February 3, 2017, the Court of Appeal dismissed his appeal in Iskandar bin Rahmat v Public Prosecutor and other matters [2017] SGCA 9.
Post-appeal litigation ended in 2025
Iskandar made several later applications. On February 4, 2025, a Court of Appeal judge rejected his last-minute application for permission to reopen the concluded criminal appeal and declined a stay of execution.
Channel NewsAsia reported that Iskandar was executed on February 5, 2025 after clemency petitions were unsuccessful. That later procedural history does not alter the editorial basis for the case's solved status: the two murder convictions had already been affirmed on appeal.
Timeline
July 10, 2013: Tan Boon Sin and Tan Chee Heong are killed at Hillside Drive.
July 2013: Iskandar is arrested in Johor Bahru after a cross-border manhunt.
December 4, 2015: the High Court convicts him on two counts of murder and sentences him to death.
February 3, 2017: the Court of Appeal dismisses his appeal.
February 4, 2025: the Court of Appeal rejects a final review application and request for a stay.
February 5, 2025: the sentence is carried out, according to Singapore police reporting cited by CNA.
Current status
The murders of Tan Boon Sin and Tan Chee Heong are Solved / Adjudicated. Iskandar bin Rahmat was convicted of both murders, the Court of Appeal dismissed his appeal, and subsequent review proceedings did not overturn those convictions.