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Defence of Insanity and Unsoundness of Mind in Criminal Trials

“A person is morally responsible if, with knowledge of the circumstances, and the absence of external compulsion, he deliberately chooses to commit a forbidden act,”

Aristotle, 500 BC

Since 2010, a now 34-year-old Malaysian man has been on death row in Singapore, after being arrested for trafficking diamorphine (pure heroin) into Singapore in April 2009. He is Nagaenthran Dharmagalingam, a man with an IQ of 69, which is one point under the internationally recognised threshold of 70 for determining the intellectual disability of a person.[i] Despite his alleged mental incapacity, the Singaporean courts sentenced him to death in accordance with Sections 7 and 33 of the Misuse of Drugs Act 1973 of Singapore (MDA), which provides for a mandatory death sentence for importing drugs as in Nagaenthran’s case. In Malaysia, after the Dangerous Drugs (Amendment) Act 2017 came into effect, there is no longer a mandatory death sentence for drug trafficking, giving courts the discretion to impose a lighter sentence upon the accused if found to be guilty.[ii] With this, the University of Malaya Law Society (UMLS) would like to dive into the issue of raising one’s intellectual disability or insanity as a defence in criminal proceedings. This defence is codified under Section 84 of the Penal Code in both Malaysia and Singapore.

Nagaenthran K. Dharmalingam, a Malaysian national, was arrested and imprisoned in 2009 while attempting to enter Singapore's Woodlands Checkpoint with 42.72g grams of diamorphine strapped to his thigh.

Nagaenthran claimed in his defence, first, that he had no knowledge of the true contents of the drugs and, second, that he had handed the drugs under duress by ‘King’, a person with whom Nagaenthran had supposedly been acquainted with four to five months before his arrest. In support of his duress claim, Nagaenthran stated that he only delivered the drugs because ‘King’ had previously threatened to murder his girlfriend, Shalini, if he did not do so. During the trial, Nagaenthran also claimed that he was instructed by 'King' and thought that the heroin included specific ‘company products’ rather than regulated drugs.

The court ruled that Nagaenthran’s defence of duress could not be shown on a balance of probability. Although it was shown that ‘King’ coerced him into providing the heroin by threatening to murder Shalini, the accused made no mention of any threat made by ‘King’ on Shalini's life when the officers first questioned him. There was also no indication that ‘King’ was a very important and powerful criminal with a swarm of followers capable of always keeping an eye on the accused and Shalini. Furthermore, Nagaenthran's statements to the officers demonstrated that he was aware that the drugs he was carrying included heroin.

As a result, he was convicted and sentenced to death in 2010 for unlawfully importing 42.72g of heroin in violation of Section 7 of the MDA, which carries a mandatory death penalty under Section 33 of the MDA. He subsequently filed an appeal to the Court of Appeal against his conviction and sentence, which was dismissed in July 2011.[iii]

However, the Singaporean MDA was amended in 2012 which came into effect in January 2013, giving all Singapore judges the discretion to sentence a drug trafficker to life imprisonment if he was merely a courier, on the condition that the Public Prosecutor issues the offender a Certificate of Substantive Assistance for assisting the narcotics police in disrupting drug trafficking activities. Another proposed requirement for receiving life imprisonment was decreased liability if any mental diseases were diagnosed and proven to have seriously affected one's mental abilities, he would likewise be unfit for the death penalty.[iv]

When the new death penalty rules came into effect, Nagaenthran appealed for re-sentencing due to clinical mental retardation and mental disease, and his case was sent back to the original trial for reconsideration in the High Court. However, the court concluded that Nagaenthran had not established that he suffered from a mental disease that severely impacted his mental responsibility for his acts, and so denied the appellant's re-sentencing appeal. Separately, the Public Prosecutor did not provide a certificate of substantive assistance under Section 33B(2)(b) of the MDA since he did not substantively help in stopping drug trafficking activities.[v]

A judicial review petition was filed on March 27, 2015 by Nagaenthran, challenging the Public Prosecutor's non-certification ruling. However, Nagaenthran's application for leave was dismissed by the court. Nagaenthran then filed an appeal, but the Court of Appeal dismissed the appeal in 2019 and upheld the High Court's ruling. The Court of Appeal further stated that Nagaenthran's statement of his crime had significant contradictions, making it difficult to rely on his defences since they affected his credibility.[vi]

Nagaenthran later appealed to Singapore’s President, Halimah Yacob, for clemency, which would have reduced his sentence to life imprisonment if successful, but his request was denied on June 1, 2020, resulting in his execution sentence.[vii] Then, Nagaenthran's family received a letter from the Singapore Prison Service (SPS) on October 28, 2021, informing them that Nagaenthran's execution date was set for November 10, 2021.[viii]

Nagaenthran subsequently filed an appeal in 2021, claiming that he was suffering from mental infirmities and hence should not be executed on November 10, 2021. The High Court denied the petition, stating that the case has exhausted all grounds of appeal since 2019, and hence there was no legal basis to not execute Nagaenthran. He filed another appeal, but the hearing was rescheduled after he tested positive for COVID-19 on November 9, 2021. The Court of Appeal then granted him a stay of execution before filing an application to vacate his death sentence, and the next court hearing for Nagaenthran's appeal was set for January 24, 2022.[ix]

As of March 1, 2022, the five-member bench of the Singapore Court of Appeal after hearing upon two arising matters in his application to set aside the death penalty which is an appeal to prohibit the carrying out of the death sentence on the grounds that it breaches provisions enshrined in the Constitution of the Republic of Singapore and a motion to allow Nagaenthran’s mental condition to be reassessed by a new panel of psychiatrists.[x] However, the bench reserved their judgment on Nagaenthran’s case to an unspecified date.

Nagaenthran’s unfortunate case has inevitably garnered attention locally and internationally. This has led to a series of oppositions from various parties including public authorities as well as non-governmental organisations (NGOs).

In Malaysia, members of parliament (MPs) have appealed to the Singapore’s government to set aside the death sentence on the grounds that Nagaenthran is mentally challenged and could not fully understand what would happen to him. On November 7, 2021, Malaysia’s Prime Minister, Datuk Sri Ismail Sabri Yaakob had written to his Singapore counterpart, Mr Lee Hsien Loong, seeking for leniency towards Nagaenthran.[xi] The Yang di-Pertuan Agong himself had also written letters to Singapore’s President Halimah Yacob, appealing for clemency towards Nagaenthran, to which the President responded that Nagaenthran ‘has been accorded full due-process under the law’, according to a Ministry of Foreign Affairs (MFA) spokesperson.[xii]

Internationally speaking, Singapore’s stance has also raised objections from a few notable human rights organisations. For instance, Amnesty International have always opposed death penalty in all cases, including Nagaenthran’s. In fact, Amnesty International’s Singapore Researcher, Rachel Chhoa-Howard, urged Singapore authorities to listen to the global outcry against Nagaenthran’s execution by introducing a moratorium on executions, as an introductory step towards a full abolition of capital punishment in the future.[xiii]

Furthermore, United Nations experts also called on Singapore to commute the death sentence against Nagaenthran, in line with international human rights law whereby under international law, countries which retained capital punishment may only impose it for the most serious offences such as intentional murder. According to the experts, death sentences should almost never be carried out, especially to persons with serious psychosocial and mental disabilities, as in Nagaenthran’s case.[xiv]

In conclusion, UMLS hopes that Nagaenthran’s application will succeed before the five-member bench of the Singapore Court of Appeal. We strongly believe that persons with mental disabilities should not be subjected to the death penalty. We humbly suggest that Nagaenthran be sentenced to a lighter sentence, such as life imprisonment. The amendments to the Singporean MDA which came into force in 2013, had given the court’s discretion to sentence traffickers with life imprisonment provided that they cooperate with authorities to disrupt drug trafficking. Unfortunately, Nagaenthran’s case does not fall within this ruling. However, a precedent had been set with the re-sentencing of Pang Siew Fum to life imprisonment due to her being diagnosed with ‘major depression order’ which amounts to ‘a substantial impairment of her mental responsibilities' similar to Nagaenthran.[xv] We hope that this unfortunate situation does not end with the execution of a person with mental disabilities.

UM Law Society 21/22

9th March 2022

[i] Paddock, R. C. (2021, November 5). Rights Groups Urge Singapore Not to Execute Man With Mental Disability. The New York Times.

[ii] Office of the High Commissioner for Human Rights. (2021). Malaysia Universal Periodic Review Mid Term.

[iii] Public Prosecutor v Nagaenthran a/l K Dharmalingam [2011] 2 SLR 830.

[iv] Baker, J. A. (2015, January 16). Murderer fails to escape the gallows: 6 other cases involving the revised death penalty laws. The Straits Times.

[v] Nagaenthran a/l K Dharmalingam v Public Prosecutor and another appeal [2019] 2 SLR 216.

[vi] Hafiz Hassan. (2021, November 18). The forensic psychiatric evaluation of Nagaenthran. The Malay Mail.

[vii] Danial Dzulkifly. (2021, November 3). Foreign minister says has raised issue of mentally-impaired Malaysian on death row with Singaporean counterpart. The Malay Mail.

[viii] Tan, A. (2021, November 6). Singapore courts found that drug trafficker facing execution knew what he was doing: MHA. The Straits Times.

[ix] Thomas, J. (2022, January 26). Nagaenthran’s appeal postponed. Free Malaysia Today.

[x] Thomas, J. (2022, January 26). Nagaenthran’s appeal postponed. Free Malaysia Today.

[xi] Devi, V. (2021, Nov 26). Another call for clemency heard for Malaysian on death row. The Star.

[xii] Channel News Asia. (2021, December 3). Malaysian drug trafficker Nagaenthran Dharmalingam ‘accorded full due process under the law’: President Halimah. Channel News Asia.

[xiii] Amnesty International. (2021, November 29). Singapore: Call of Execution of man with intellectual disability. Amnesty International.

[xiv] United Nations. (2021, November 21). Rights Experts urge Singapore to half execution of man with mental disability. UN News.


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