With the exception of an interlude from 1966 to 1976, the death penalty has been allowed under U.S. federal law since the founding of the country. There has been a growing sentiment, however, that its authorized use by the State should be terminated.
The central questions framing the death penalty debate, which I’ll discuss, include:

  • Is capital punishment consistent with the fundamental principles of a free society, or does it exceed the proper limits of governmental authority?
  • Is it consistent with the norms of a just society?
  • Is it effective as a deterrent against crime?
  • Does it satisfy principles of just deserts or retribution, or is it more fundamentally a violation of 21st century norms of decency—a cruel and unusual punishment, in violation of the Eighth Amendment?
  • Is the sanction permissible in light of the prospect that an innocent person might be executed, especially in the face of findings that several people sentenced to the death penalty have in fact been wrongfully convicted?

Let us take up each of these issues in turn, starting with the question of whether the death penalty exceeds the proper limits of governmental authority.

Does the Death Penalty Exceed the Proper Limits of State Authority?

The Supreme Court has ruled repeatedly that the death penalty is within the proper boundaries of Constitutional authority. The Court has become increasingly divided, however, over whether the State should continue to have such awesome authority. The divided nature of the Supreme Court notwithstanding, some have argued that the sanction violates a fundamental right of citizens under the “cruel and unusual” clause of the Eighth Amendment to the Constitution, regardless of the heinousness of the crime.
Still others argue that capital punishment violates fundamental principles—in particular that it exceeds the proper authority of the state. A government that cannot be trusted on lesser matters surely cannot be trusted to use the most severe sanction available prudently in matters of life and death.

Does the Death Penalty Conform to the Norms of a Just Society?

There are two conflicting moral arguments on the death penalty. The right-wing position holds that capital punishment is needed to satisfy principles of just deserts and retribution, especially when the crime committed is heinous in the extreme. Advocates of this position argue that the death penalty conforms to the norm of proportionality, despite the fact that both Cesare Beccaria and Jeremy Bentham, the two iconic 18th century philosopher proponents of the principle of proportionality, opposed the death penalty.
The left-wing position argues that capital punishment fundamentally violates 21st century norms of decency. Advocates of this position hold that the death penalty is cruel and unusual, beyond the proportionality boundaries set by Beccaria and Bentham. The United States stands virtually alone among Western nations in its continued use of the sanction, although at an increasingly diminished rate.
Some libertarians on the left have observed also that capital punishment has not been used in an even-handed manner, thus violating a bedrock principle of justice.  Just two percent of all counties account for 52% of all executions since 1976. And this is not primarily due to the fact that these counties have disproportionately more homicides. In Texas, for example, Houston had eight percent more murders than Dallas in 2005, but 324% more death row inmates; 15% more murders than San Antonio, but 430% more death row inmates. In Maryland, controlling for case characteristics in cases eligible for capital punishment, the probability that the prosecutor will file a notification to seek the death penalty is 13 times higher in Baltimore County than in the city of Baltimore.

Do Executions Deter Crime?

In 1976, the Solicitor General of the United States introduced evidence in support of the deterrent effect of the death penalty in the case of Gregg v. Georgia. Numerous scholars over the ensuing decades analyzed the evidence and concluded that that analysis was mostly invalid, that the evidence can be as easily interpreted as supporting a counter-deterrent effect.
The most popular position among scholars who study the deterrent effect of the death penalty is that the collective evidence is too weak to support the conclusion of an effect in either direction.  The research will continue, although the small and dwindling numbers of executions makes it increasingly difficult to test for deterrent effects in the United States. The best that can be said of the effect of the death penalty on further crimes is that it ensures that the offenders executed will not offend again. Opponents respond that the alternative of life without parole effectively accomplishes the same result.

Does Capital Punishment Satisfy the Principle of Just Deserts (or Retribution)?

Many advocates who support the death penalty argue that it satisfies a basic norm of justice: lex talionis or “eye for an eye”—a capital offender ought to be executed simply because it is justly deserved, regardless of its effectiveness as a deterrent. According to this argument, to administer a lesser sanction is to create an error of impunity; the penalty is not only proportional to the crime, but is essentially equivalent; anything less would be unjust.
The counter-argument to this position is that if we are to justify a sanction for a capital offense on grounds of pure justice, the imposition of a life term is not only proportionate, but also more readily justified on moral grounds, since the death penalty violates fundamental norms of decency, as noted earlier in this essay. The case for proportionality includes the idea that spending a life in prison is unpleasant—for many offenders even more unpleasant and punitive than a relatively painless execution.

Should Capital Punishment be Allowed if it Means that an Innocent Person Might Be Executed?

One of the more compelling arguments against the death penalty is that it is irreversible, ending opportunities to correct miscarriages of justice in the conviction of a factually innocent person. Advocates of this position argue that many people, in fact, have been sentenced to death row, only to be exonerated afterward because of conclusive evidence of wrongful conviction.
A counter-argument to this position is that the vast majority of people wrongfully convicted for capital offenses end up serving life terms without parole, with decades of discomfort and deprivation of liberty. Given the choice, many of these people might prefer an execution delivered in the same humane manner that is used commonly to euthanize sentient beings. While an execution closes all windows of reversibility, the unfortunate fact is that the vast majority of wrongful convictions in capital cases receive a sanction that is little better for most of those affected and worse for some.

What Is the Future of the Death Penalty?

So, where is all this taking us? Advocates continue to support the death penalty on both utilitarian and moral grounds, arguing that it ends any prospect of further crimes by the offender and that it can be justified on grounds of pure justice. But this case grows increasingly weak as the evidence mounts that the death penalty does not deter, that it is assigned erroneously too often to innocent people, and that it is assigned to others in an arbitrary manner that lacks evenhandedness.