With the fate of Australian drug smugglers Andrew Chan and Myuran Sukumaran seemingly decided by the Indonesian legal system, Australian advocates for the pair have been attempting to secure a reprieve through legal avenues and public pressure.
During a visit to Bali in February, Victorian Supreme Court judge Lex Lasry told ABC TV's 7.30 that the death penalty does not deter crime.
"There are all sorts of other punishments - life imprisonment and so on - but the idea that a government would take individuals out into the bush, as they would here, and shoot them is just something that I can never live with and never understand, and apart from anything else, from a legal point of view, no-one really claims now that it has any real deterrent value. It's just a terrible thing to do," he said.
ABC Fact Check looks at the research.
The death penalty
More than half of all the nations in the world retain the death penalty in some form or other. A small number retain it only for war-time offences and others have not used it for over 10 years, but there are a large number that retain and use the death penalty, predominately as a punishment for murder.
According to advocacy group Harm Reduction International, thirty-three nations retain the death penalty for drug offences. Of those, not all carry out capital punishment for these offences on a regular basis, and Harm Reduction International estimates that "executions for drug offences have taken place in only 12 to 14 countries over the [five years to 2012]".
It lists six countries with a "high" rate of applying the death penalty in drugs cases: China, Iran, Vietnam, Saudi Arabia, Singapore and Malaysia.
Oxford University professors Roger Hood and Carolyn Hoyle say Indonesia, which resumed executions for drug traffickers in 2013, might soon be added to that list "if it carries out its threat to execute more drug traffickers".
In the fifth edition of their book The Death Penalty: A Worldwide Perspective released in January, Professors Hood and Hoyle write that Singapore, Malaysia and possibly Vietnam may be "ready to be downgraded to 'low application states'."
The United Nations has strict guidelines for the use of the death penalty, restricting it to the "most serious crimes".
A resolution of the Economic and Security Council, first made in the 1980s, endorsed by the UN General Assembly in December 1984, and updated in 1999 says that "capital punishment may be imposed for only the most serious crimes, it being understood that their scope should not go beyond intentional crimes with lethal or other extremely grave consequences".
Since the adoption of this guideline, other UN bodies have made rulings about how to interpret the "most serious crimes" provision, which exclude drug offences. And the UN's Special Rapporteur on extrajudicial executions, Christof Heyns, said recently that Indonesia was a signatory to the International Covenant on Civil and Political Rights and its use of the death penalty for drug offences was "in violation of international human rights standards".
A review of Indonesia's use of the death penalty and the Bali Nine case by Colman Lynch, published in the Columbia Human Rights Law Review in 2009, says capital punishment is also arguably against Indonesia's constitution.
Mr Lynch wrote that "though Indonesia had a legal obligation to abolish capital punishment as a punishment for drug-trafficking crimes under its constitution and applicable international law, as interpreted by relevant international bodies, its judiciary was able to find sufficient ambiguity in the wording of each obligation to buck the international trend of abolishing capital punishment".
The death penalty in the United States
Fact Check asked Justice Lasry whether he had any particular research in mind when he said the death penalty wasn't a deterrent. A spokeswoman for the Victorian Supreme Court said that the judge's comments were based on "a general body of research that indicates the death penalty has no real deterrent value".
In their book, Professors Hood and Hoyle say almost all the academic studies available for review are concerned with the deterrent effect of capital punishment on the rate of murder in the United States.
The authors say theoretical and methodological issues have "dogged the attempts to prove or disprove the existence of the deterrent effect of executions in the United States" and "a fierce controversy continues" in the United States over attempts to use econometric models to address the question.
After reviewing the literature they conclude that "it is not prudent to accept the hypothesis that capital punishment, as practised in the United States, deters murder to a marginally greater extent than does the threat and application of the supposedly lesser punishment of life imprisonment".
A comprehensive review of the research in this area over 34 years was conducted in 2012 by a committee of the American National Academy of Sciences National Review Council. The committee concluded that "research to date on the effect of capital punishment on homicide is not informative about whether capital punishment decreases, increases, or has no effect on homicide rates".
It said the studies it reviewed should not be used to influence policymakers. "Claims that research demonstrates that capital punishment decreases or increases the homicide rate by a specified amount or has no effect on the homicide rate should not influence policy judgments about capital punishment," it said.
One of the main problems was that it was impossible to know what a jurisdiction's murder rate would be with different sentencing options. "The data alone cannot reveal what the homicide rate in a state without (with) a capital punishment regime would have been had the state (not) had such a regime."
A second problem was "the use of incomplete or implausible models of potential murderers' perceptions of and response to the capital punishment component of a sanction regime".
Without this basic information, "it is impossible to draw credible findings about the effect of the death penalty on homicide".
While that review found the evidence was inconclusive, Jeffrey Fagan, a professor of law at Columbia University in the US, told Fact Check he believed that there was no evidence that showed the death penalty deterred.
Professor Fagan, who appeared as an expert witness for Mr Chan and Mr Sukumaran in an unsuccessful appeal in 2007, said there was "no credible scientific evidence that the death penalty deters criminal behaviour".
"Even when executions are frequent and well-publicised, there are no observable changes in crime. Executions serve only to satisfy the urge for vengeance. Any retributive value is short-lived, lasting only until the next crime."
His position is shared by the majority of criminologists in relation to homicide, according to a 2009 survey of members of the American Criminology Society, who were asked to limit their answers to their understanding of the empirical research and to exclude their personal opinions.
That study found that over 88 per cent of the criminologists did not believe the death penalty deterred murderers.
"In short, the consensus among criminologists is that the death penalty does not add any significant deterrent effect above that of long-term imprisonment," the study said.
Professor Franklin Zimring of the University of California, Berkley, told Fact Check the evidence wasn't there to support the argument that the death penalty acted as a deterrent to murder.
"The number of homicide studies over the past century is vast and there is no consistent evidence of marginal deterrent effect," he said.
Murder, the death penalty and Asia
Professor Zimring, with Professor Fagan and David T. Johnson of The University of Hawaii, conducted a study that compared Singapore - a country that does have the death penalty - with Hong Kong.
According to the study, in the mid 1990s, Singapore's execution rate was among the highest in the world. There was a steep drop off in the decade after 1997 - a reduction of an estimated 95 per cent.
Hong Kong abolished the death penalty in 1993.
The three concluded that "the Singapore experience magnifies the impact of American assertions [that the death penalty deters] to a patently silly status".
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's executions nor the more recent steep drop producing any differential impact".
In South Africa, the Constitutional Court considered the issue in 1995, and in a judgement that struck out use of the death penalty, said:
"We would be deluding ourselves if we were to believe that the execution of the few persons sentenced to death during this period, and of a comparatively few other people each year from now onwards will provide the solution to the unacceptably high rate of crime. There will always be unstable, desperate, and pathological people for whom the risk of arrest and imprisonment provides no deterrent, but there is nothing to show that a decision to carry out the death sentence would have any impact on the behaviour of such people, or that there will be more of them if imprisonment is the only sanction."
The court rejected the argument of the Attorney General that the death penalty was a powerful deterrent.
The death penalty and drug offences
When it comes to assessing deterrence in relation to drug-related crime, Harm Reduction International says finding reliable ways to measure the impact of executions is a big challenge for researchers.
- "*A plethora of indicators could be used to consider deterrence with drugs," it says in its 2012 global review of the death penalty for drug offences.
"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. 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."
In their book, Professors Hood and Hoyle agree that producing evidence is difficult. They write that in all 33 countries with the death penalty for drug offences, "it has been argued that the death penalty is an indisputable deterrent to drug trafficking, but no evidence of a statistical kind has been forthcoming to support this contention".
What's more they say it is unlikely that any such evidence could be gathered.
"The low rates of effectiveness of law enforcement, the relative immunity from the law of those who profit most from the trade in drugs, and the higher risks of violence and death they most probably run from others engaged in the drugs trade, all make it seem implausible that the death penalty in itself will have a marginally stronger deterrent effect than long terms of imprisonment, especially when ... only 11 of 33 countries with power to execute offenders for drugs offences have actually done so within the past 10 years."
In Mr Lynch's 2009 review of Indonesia's use of the death penalty and the Bali Nine case, he quotes Professor Fagan's expert testimony used in an attempt to appeal the death sentences for Mr Chan and Mr Sukumaran on a human rights basis.
Professor Fagan "described extensive studies showing that criminals are deterred more by an increase in their likelihood of apprehension than by an increase in the magnitude of their punishment, meaning that likely capture is a more effective deterrent than potential death," Mr Lynch wrote.
Professor Fagan argued that the comparative drug crime rates in Singapore and Indonesia, when compared with death sentences handed down showed that there was no deterrent effect.
"If capital punishment had a deterrent effect on drug trafficking, this would lead to less drug trafficking, and therefore higher wholesale drug prices, in Singapore. However, wholesale drug prices for both cocaine and heroin were significantly higher in Indonesia than in Singapore from 2003 to 2006, and drugs generally were more prevalent in Singapore than Indonesia in that period, indicating that drug trafficking was not deterred as a result of Singapore's high levels of capital punishment," the article says.
Mr Lynch wrote that a typical factor in drug-trafficking cases is the potential for large monetary gains, for which a trafficker might be prepared to risk even the death penalty. He quoted research discussing "the overwhelming effect of drug smugglers' potential financial gains, including one smuggler's comment that 'the money overrode any—any rational judgment'."
There is scant research on whether the death penalty deters drug trafficking. Experts who have considered the issue of the death penalty as a punishment for murder, and in some cases drug offences, around the world, say there is not enough evidence to conclude that the death penalty deters.
Justice Lasry's claim that it has no real deterrent value is well founded.
- Interview with Lex Lasry, ABC 7.30, February 11, 2015
- International Harm Reduction Association Death Penalty Report, 2012
- United Nations Economic and Social Council Resolution 1996/15
- United Nations General Assembly 1984 resolution 'Human rights in the administration of justice'
- United Nations Special Rapporteur on extrajudicial execution, media statement, February 13, 2015
- Deterrence and the Death Penalty
- Do executions lower homicide rates?
- Executions, Deterrence and Homicide: A Tale of Two Cities
- The Use of the Death Penalty for Drug Trafficking in the United States, Singapore, Malaysia, Indonesia and Thailand: A Comparative Legal Analysis
- Indonesia's Use of Capital Punishment for Drug Trafficking Crimes
- State v T Makwanyane and M Mchunu, Constitutional Court of the Republic of South Africa
- Uses and Abuses of Empirical Evidence in the Death Penalty Debate
- The Death Penalty: No Evidence for Deterrence
- The Death Penalty: A Worldwide Perspective, 2015 edition