This is probably the biggest question surrounding the debate on the Mandatory Death Penalty (MDP) and perhaps, the death penalty itself. Sure, other reasons are also cited in support of capital punishment, but none as frequently, like the one on its perceived deterrent effect on crime.
In Singapore, the government, as well as proponents of the death penalty, frequently point to the fact that the prevalence of drug problems or murders in our society is far lower than those in places which do not have the death penalty. But is this really down to the presence of the death penalty or is the relatively low crime rate driven by other factors which are just as important, or perhaps even more important than the death penalty itself?
It would seem that there is a severe lack of evidence to support the proposition that the death penalty is indeed a significant deterrent for capital crimes.
In his reply to questions from Members of Parliament, the Minister for Law, Mr. K Shanmugam indicated that the government’s most recent studies on the relevance of the MDP were carried out in 2006, 2009, 2010 and 2011. These studies concluded that it was in the public interest to retain the mandatory death penalty and to provide for limited circumstances where it would not apply.
What is problematic, however, is that the government has not published these studies to allow us to test the veracity and accuracy of their conclusions. This is not only against the spirit of transparency and accountability, it also weakens the government’s case for retaining the mandatory death penalty. Further, criminological studies point in the opposite direction.
In general, they have not been able to show that the death penalty is a significantly better deterrent than the next most severe punishment – life imprisonment.
In a recent study titled, “Executions, Deterrence and Homicide: A Tale of Two Cities’’, three eminent criminologists undertook a study which compared the homicide rates of Hong Kong and Singapore, two cities with very similar demographics with the difference being that one retains the death penalty for murder and makes it mandatory while the other has abolished the death penalty completely.
In the paper, the authors observed that Hong Kong experienced consistent fall in homicide rates in the 35 years after 1973 despite having abolished the death penalty in practice in 1966 and then in law in 1993*. But the more important observation is that the trend was generally similar in Singapore, even with the mandatory death penalty being retained for murder since its independence.
What this tells us, the authors argue, is that the argument that the death penalty is a significant deterrent is flawed. While they also concede that zero deterrence cannot be proved and that there is the possibility of a few marginal cases where the punishment has a deterrent effect, the general decline of homicide rates in a city without the MDP and a corresponding trend in one which retains the MDP, strongly suggests that other factors assume greater importance.
The authors have also argued elsewhere that the same principles apply for other capital crimes such as drug trafficking and they consistently maintain that there is no scientific evidence to show that the death penalty is an effective deterrent to homicide or drug crimes.
Even if the MDP does have a deterrent effect in marginal cases, the real question that needs to be asked is whether this can be achieved by less extreme forms of punishment. For example, a person who may indeed be deterred from capital crime by the death penalty may also be referred to the same extent by life imprisonment. In this context, the necessity of imposing the death penalty ceases to exist and it becomes almost impossible to justify.
Again we would reiterate that the government has not put forward evidence to contradict the strong evidence against its case. We would also urge the government to publish data and information to back up its stand on the deterrent effect of the death penalty and its mandatory application. This is consistent with its support of the United Nations’ Human Rights Council’s position to make available statistics and other factual information on the use of the death penalty. The government assured the Council that the provision of such data has already been implemented or was in the process of being implemented.
Framed as a criminal justice issue, the death penalty and its mandatory application have not been adequately justified in light of evidence to the contrary. On the available evidence, the connection between our low capital crime rates and the presence of the MDP is tenuous at best, and cannot be used to justify the continued use of a punishment that is not only extremely harsh but also irreversible.
The paper, Executions, Deterrence, and Homicide: A Tale of Two Cities is available for download here.
*Correction: The death penalty was abolished in practice in Hong Kong in 1966 and abolished in law in 1993. The writer omitted to mention the first part of the statement. Any inconvenience is regretted.