The other is his 42-year-old son, Tan Chee Heong, whose body was dragged for 1 km, under a car driven by the killer before being dislodged outside Kovan MRT station.
[6] According to his family, friends, colleagues and neighbours, Boon Sin was a very nice and hard-working person, a caring employer to his co-workers, and a kind, jovial, and even-tempered man who was close to his wife and three children (including Chee Heong) and never smoked or gambled.
A Malaysian employee of Boon Sin's car workshop recalled the kindness his late employer showed him when he handed him his six months' worth of salary even when he was not working to take care of his ailing wife in Malaysia.
Upon receiving the news of the suspect's arrest, then-Deputy Prime Minister Teo Chee Hean thanked the RMP, saying this was "an excellent example of the close and deeply valued partnership the law enforcement agencies of both countries have built over many decades".
[14][15] By then, the DPM Teo Chee Hean and Police Commissioner Ng Joo Hee had addressed the public and reporters about his arrest in a press conference, and for the first time, they revealed Iskandar's identity.
This revelation brought a shock to all Singaporeans, including former police officers, MPs and netizens, that a senior policeman was involved in the double deaths at Kovan.
Not only did Teo offer his condolences to the bereaved families of the victims, he also expressed his shock over the first time when he heard that the suspect was a senior policeman, and his actions had tarnished the reputation of the Singapore Police Force.
[17] Upon receiving news of Iskandar's arrest and his identity as a police officer, the bereaved Tan family demanded justice and expressed their shame that a policeman was involved in the deaths of Boon Sin and Chee Heong.
More visitors, including the long-time customers of Boon Sin's car workshop and the Workers' Party Members of Parliaments (MPs) Sylvia Lim (from Aljunied GRC) and Lee Li Lian (from Punggol East) also came to the funeral to pay their respects.
[21] Even the teachers and counsellors from the school of Chee Heong's elder son were sent to help the Primary Four student and his family to cope through the double loss and difficult time they suffered.
The officer in charge had also mentioned to Iskandar that discharging his debts would help mitigate the consequences if he was found guilty of his failure to declare his financial problems.
Many members of the public, including law students, reporters and curious onlookers came to the court to witness the proceedings in the Kovan double murder trial.
[32] One of these witnesses, was associate professor and senior forensic consultant pathologist Dr Gilbert Lau from the Health Sciences Authority (HSA), who conducted an autopsy on the deceased father and son.
As he was testifying and presenting his autopsy findings in court on the third day of the trial (26 October 2015), Dr Lau faced a severe cross-examination from defence lawyer Shashi Nathan, who put it to him that Iskandar had done the stabbing out of self-defence, which the pathologist rejected on the stand.
He said that, even if Iskandar had exceeded his right to self-defence and had committed murder, he should be convicted of a lesser limb of third-degree murder with lack of intention to kill under Section 300(c) of the Penal Code, which constitutes an act where a person intentionally inflict a bodily injury on another person, and the bodily injury itself is sufficient in the ordinary cause of nature to cause death, for which the punishment is either a sentence of death or life imprisonment with/without caning.
Iskandar's lack of explanation of why he inflict so many wounds on the victims and the inconsistencies between his account and the objective evidence were also included in the arguments of the prosecution in favour of a conviction of murder.
[47] Boon Sin's widow was reported to have been struggling with accepting the deaths of her husband and son, and had not made any reaction to the Kovan murder verdict.
Justice Phang read out, "Even if his incredible account of a rob-and-run ploy were true, any right of self-defence belonged to the younger victim [Tan Chee Heong], who came home to the sight of his slain and bloodied father on the floor."
Especially on the part of the younger victim, Justice Phang said that "[Chee Heong] had just witnessed [Iskandar] lowering his father's limp and bloodied body on the floor.
The judges also rejected the newly raised defence of diminished responsibility, questioning why it was not brought up in the original trial or during Iskandar's time of psychiatric remand.
"[55] Simultaneously, while he was under a sentence of death and awaiting the outcome of his clemency application, Iskandar filed a complaint against his original lawyers to have them subject to disciplinary tribunal for not handling the case ethically and properly.
[61] Still, it was not the end of the story for Iskandar and 12 other prisoners out of the 22 plaintiffs, as they have filed civil suits against the Attorney-General of Singapore for this issue and asked for the High Court to declare the forwarding of letters to the AG as unlawful.
The 36 plaintiffs argued that the new law was discriminatory against death row inmates and it would hinder the last chances of the convicts' access to justice, which also violated the need for fairness during the legal proceedings.
However, 11 days after the appeal was filed, Justice Dedar Singh Gill found there was no reasonable cause of action and dismissed the motion, as the LASCO was "perfectly entitled to adopt or change its policy regarding its provision of legal aid", and there could have been multiple reasons for LASCO to not assign lawyers for such convicts, such as the need to allocate resources to aid new defendants who were facing trial and appeal and deter possible abuse of court processes.
The judge also stated that the lack of representation from LASCO in post-appeal applications did not deprive the accused persons of their right to life or personal liberty, which was especially so since all the plaintiffs in this case were already convicted and sentenced at this stage, and also exhausted their appeals against conviction and/or sentence, and their rights to access to justice were not violated by the lack of free legal representation, given that they still had the entitlement to engage lawyers on their own accord in any post-appeal applications.
[74][75] According to court sources, Iskandar filed a second petition for clemency on 17 November 2024, but President Tharman Shanmugaratnam rejected the plea prior to his execution.
[76] Iskandar's execution in 2025 was noted to be unusual as his sentencing took place nearly ten years before in 2015, and that he lost his direct appeal and clemency plea in 2017 and 2019 respectively.
Typically, a condemned inmate in Singapore would be hanged around a few weeks or two months after losing their clemency plea, but Iskandar's execution was delayed for at least five times and took another six years to come due to his multiple legal challenges against capital punishment and a complaint alleging the misconduct of his former trial lawyers.
Boon Sin's daughter also said that her mother was still in good health and they hoped to move on after the hanging of Iskandar, which was relayed to the family by the Criminal Investigation Department before it was carried out.
[79][80] A veteran employee of Tan Boon Sin's workplace also stated that he was greatly relieved at the execution of Iskandar after 12 years of waiting for justice to be served, and the 66-year-old Malaysian-born employee, who had worked with Tan since the age of 21 after moving from Malaysia, stated that he never forgotten about the case and he struggled to move on for the first five to six years after the murders, and he revealed that many of the regular customers had been inquiring him about the fate of Iskandar.