The death penalty, a deterrent?

Given the harsh and irreversible nature of capital punishment, those who advocate its use should be required to provide incontrovertible evidence not only of each accused person’s guilt, but that the entire regime itself is absolutely necessary for the purposes of justice and public safety.

The question of whether the death penalty deters crimes such as murder or drug trafficking has long been a matter of debate among criminologists, researchers, politicians, activists, and members of the public around the world. Recently, Workers’ Party Member of Parliament Jamus Lim filed a question in parliament asking the Minister for Home Affairs if 

“(a) whether there has been any systematic study by the Ministry as to the deterrent effect of a life sentence relative to the death penalty; and
(b) whether the study has been conducted in cases where the reasoning capacity of the perpetrator may have been compromised such as by mental illness or addiction.”

In his written response, Minister for Home Affairs K Shanmugam asserted that the death penalty is a deterrence to crime, pointing to data points such as drops in firearms offences and kidnapping, and the reduction of the net weight of trafficking in drugs like opium and cannabis following the introduction of capital punishment. He also pointed to surveys showing that Singaporeans and foreigners think that the death penalty is more effective than life imprisonment in deterring crime.

We are troubled by the minister’s response. His answers do not satisfactorily address Dr Lim’s questions, and have actually done a disservice to the Singapore public by not adequately providing the necessary information and evidence that would contribute to informed public discourse on the issue of capital punishment.

Here are some of the issues with the minister’s response:

People feeling that the death penalty works ≠ The death penalty works

In bringing up surveys and studies conducted by the Ministry of Home Affairs — which, we note, are not publicly accessible for independent scrutiny and review — on whether Singaporeans and foreigners believe that the death penalty is more effective than life imprisonment in deterring crime, the minister has conflated public belief with evidence. But people believing a hypothesis to be true does not actually make that hypothesis true, which is why a survey of opinions is insufficient in proving any claims about the death penalty’s effect on crime.

Furthermore, the Singapore government has repeatedly and consistently insisted — particularly in the mainstream media and in campaigns targeted at students and young Singaporeans — that the death penalty is a deterrent to crime, while many other aspects of the application of the death penalty are kept from public view, making it difficult for Singaporeans to gain a full picture of how the death penalty actually works in their own country. It is therefore rather circular for the government to then survey Singaporeans about whether they agree that the death penalty is a deterrent, and use it as a basis to assert the their view on the deterrent effect of capital punishment.

Correlation is not causation!

The question of what makes crime rates go up or down can be a complex one. There are a variety of factors that have an effect on whether people commit crimes; these include, but are not limited to, variables like socio-economic circumstances, education, psychosocial disabilities, and effectiveness of law enforcement. Penalties as stipulated by law are only one part of the puzzle. One cannot simply claim that a single variable — such as the existence of capital punishment — is the sole cause of crime going up or down. In this case, a correlation between the imposition of the death penalty and rates of a particular offence decreasing is not enough to be taken as proof of a deterrent effect.

For example, it is reductive to claim, as the minister has, that the death penalty works as a deterrence simply because firearms robberies have fallen in Singapore. Even without the death penalty, Singapore has strict laws pertaining to the issuance of firearm licences and the use of firearms. This has minimised and de-normalised private ownership of firearms over decades. We cannot discount such measures when we consider the drop in the number of robberies involving firearms in Singapore.   

Scholarship on Singapore’s death penalty and its contested deterrent effect does exist. In 2010, Franklin E. Zimring, Jeffrey Fagan, and David T. Johnson published a paper in the Journal of Empirical Legal Studies comparing homicide rates in Hong Kong, which does not have the death penalty, with that of Singapore, which does. They found that “[homicide] levels and trends are remarkably similar in these two cities over the 35 years after 1973, with neither the surge in Singapore executions nor the more recent steep drop producing any differential impact.”

A deterrent for drug trafficking — how do we tell?

The minister also pointed to specific examples with drugs to make an argument for a deterrent effect, stating that the average weight of opium and cannabis seized fell in the four years after the mandatory death penalty was introduced for trafficking over stipulated amounts of the narcotics in 1990.

Looking on, we were unable to find the figures for the amounts of opium and cannabis seized during that period — the data on the amount of controlled drugs seized in Singapore only went back as far as 2003.


Looking at the amounts of opium and cannabis seized between 2003 and 2019, it is difficult to draw conclusions about the impact of the death penalty, which has been in place throughout this whole period. In fact, the amount of cannabis seized in 2019 is higher than the amount seized in 2003, with significant spikes in 2016 and 2018.


We also decided to take a look at the amounts of heroin seized from 2013–2019, since we have often seen death row inmates hanged for trafficking heroin.


From the data, the amount of heroin seized has generally increased between 2003 and 2019, even though trafficking 15g and above of heroin would attract the mandatory death penalty during this period.

Such data about the amount of drugs seized is woefully inadequate for arriving at a conclusion on the efficacy of capital punishment. Firstly, we have no idea how these amounts of opium, cannabis, heroin, or any drug provided in the data, relate to the overall amount of such drugs imported into or circulating in Singapore. Do these seizures represent a large proportion of the total amount of such drugs? Or are they only a small fraction of what’s out there? As it is, it is difficult for us to truly understand the context within which such seizures have occurred.

Fluctuation in the weight of drugs seized also cannot be attributed to a single factor like the death penalty. There are multiple reasons why more or less of a drug might be trafficked into or sold in Singapore. Particular drugs might go in or out of fashion, or there might be disruptions that might affect supply. There might also be changes in law enforcement activity that have an impact on effectiveness.

Attempting to identify the impact of capital punishment on drug offences is a tremendously complex task. As Harm Reduction International has observed:

“A plethora of indicators could be used to consider deterrence with drugs. Might it be arrests for drug offences? Representation of drug offenders in the prison population? Hospital admissions for drug-related issues? Overdose statistics (which can be brought down anyway with simple and cheap harm reduction interventions)? Moreover, which drugs: marijuana, cocaine, heroin, so-called ‘party drugs’ like ecstasy? Would a reduction in arrests for marijuana represent a successful indicator for all drugs? Trying to prove or disprove the deterrent value of drug laws is extraordinarily difficult.” 

The international NGO goes on to say: “Anecdotally, one could say harsh drug laws do not work. For example, Iran has some of the toughest drug laws in the world and a high prevalence of injection drug use. Sweden does not have the death penalty and it has comparatively low rates of problematic drug use.”

This brings up another point: if one wants to justify the use of the death penalty by arguing for its necessity on the grounds that it is the most effective method, one would also have to account for countries that are doing well in relation to drugs despite not having capital punishment. The onus would be on those advocating for the death penalty for drug offences to explain why we do not adopt the approaches of those countries, instead of persisting with state-sponsored executions.

Do Singaporeans support the death penalty?

As a human rights issue to do with life and death, the death penalty should not be an issue that is open to referendum or the whims of the majority within a society. 

Despite this, the Singapore government often refers to strong public support to justify its continued retention of capital punishment. This makes it relevant for us to interrogate whether support for the death penalty is as strong as we have been led to believe.

For this, we refer to a survey, based on a public opinion survey instrument designed by Roger Hood, Professor Emeritus of Criminology at Oxford University, conducted by academics at the National University of Singapore, Singapore Management University, and human rights group MARUAH.

While the survey did find that, generally, the majority of the respondents in Singapore supported the death penalty, it also found that interest in and knowledge of the capital punishment regime was fairly low. Support of capital punishment also wavered when people were presented with a range of scenarios. In their conclusion, the researchers noted that:

“…the support for the death penalty in Singapore is not as strong as it appears. There was a much lower support for the death penalty when respondents were faced with scenarios of cases—all of which would have merited the mandatory sentence under the current Singapore law—than the proportion who said they favoured it in the abstract. This was particularly so for drug trafficking and firearm offences. This finding is consistent with surveys in other places which also showed that support for the death penalty dropped when respondents were given alternative sentencing options such as life imprisonment without parole or life imprisonment without parole and a requirement that the convicted offender work in prison for earnings which will go towards murder victims’ families. It would therefore be misleading to say, without qualifications, that there is majority support for the death penalty in Singapore.”

What we’ve seen

As a collective with members who have been involved in documenting and tracking the use of the death penalty for years, we would like to proffer some observations gleaned from our interactions with the families of various death row inmates, some of whom are still on death row, while others have already been executed.

In our work, we have repeatedly found that individuals who end up on death row tend to come from disadvantaged or marginalised communities and backgrounds, despite it being known that drug consumption is also prevalent among Singapore’s monied classes. From the inmates that we know of, as well as anecdotal information from the families of death row inmates, we believe that a disproportionate number of death row inmates, past and present, come from ethnic minority communities. 

Some of the inmates, such as Yong Vui Kong and Cheong Chun Yin, had been victims of manipulation. Others, such as Nagaendran K Dharmalingam, say that they had smuggled drugs under duress. Still others turned to drug trafficking out of a desperate need for money, like Gobi Avedian, who was trying to get money for his daughter’s medical fees. Then there are those, who, like Syed Suhail bin Syed Zin, themselves struggle with addiction.

Click here to watch our interview with Syed’s sister Mila.


We agree with the government that it is important to ensure safety and security for all Singaporeans. However, we believe that a punishment as harsh as the death penalty cannot be maintained simply out of a belief that it works. That cannot be a sufficient basis upon which to take the lives of human beings, even if they have made mistakes.

There is no conclusive evidence that the death penalty is more effective than any other punishment at deterring crime. Given the response provided by Minister K Shanmugam, which we have responded to here, we can only conclude that the Singapore government does not actually have concrete evidence that capital punishment is the only way to keep Singapore safe.

It is crucial that Singaporeans are able to engage in informed discussions on an issue as important as capital punishment. The government should make more information related to the use of the death penalty publicly accessible, and not assert more than their data points can properly support.

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