PRINCETON ― Three significant events relating to the death penalty occurred in the United States during September. The one that gained the most publicity was the execution in Georgia of Troy Davis, who had been convicted of the 1989 murder of Mark McPhail, an off-duty police officer.

Davis’ death sentence was carried out despite serious doubts about whether he was guilty of the crime for which he received it. Witnesses who had testified at his trial later said that prosecutors had coerced them. Even death-penalty supporters protested against his execution, saying that he should be given a new trial. But the courts denied his appeals. In his final words, he proclaimed his innocence.

The deliberate judicial killing of a man who might have been innocent is deeply disturbing. But the execution was consistent with something that happened just two weeks earlier, at one of the debates between Republican candidates for their party’s nomination to challenge President Barack Obama next year. Texas Governor Rick Perry was reminded that during his term of office, the death penalty has been carried out 234 times. No other governor in modern times has presided over as many executions. But what is more remarkable is that some audience members applauded when the high number of executions was mentioned.

Perry was then asked whether he was ever troubled by the fact that one of them might have been innocent. He replied that he did not lose any sleep over the executions, because he had confidence in the judicial system in Texas. In view of the record of mistakes in every other judicial system, such confidence is difficult to justify. Indeed, less than a month later, Michael Morton, who had served nearly 25 years of a life sentence for the murder of his wife, was released from a Texas prison. DNA tests had shown that another man was responsible for the crime.

As September drew to a close, the U.S. Supreme Court reached its decision in the case of Manuel Valle, who had been sentenced to death 33 years earlier. Valle had asked the court to halt his execution, on the grounds that to spend so long on death row is “cruel and unusual punishment” and therefore prohibited by the U.S. constitution.

Justice Stephen Breyer agreed that to spend 33 years in prison awaiting execution is cruel. In support of that view, he pointed to “barbaric” conditions on death row, and the “horrible” feelings of uncertainty when one is under sentence of execution but does not know whether or when the sentence will be carried out. Breyer then went on to document the fact that so long a period on death row is also unusual. It was, in fact, a record, although the average length of time spent on death row in the U.S. is 15 years; in 2009, of 3173 death-row prisoners, 113 had been there for more than 29 years.

So Breyer held that Valle’s treatment was unconstitutional, and that he should not be executed. But he found no support for his position among the eight other Supreme Court judges. On Sept. 28, the court rejected Valle’s application, and he was executed that evening.

The U.S. is now the only Western industrialized nation to retain the death penalty for murder. Of 50 European countries, only Belarus, notorious for its lack of respect for basic human rights, still executes criminals in peacetime. The European Union’s Charter of Fundamental Rights regards the death penalty as a human-rights violation.

The death penalty is not an effective deterrent. Murder rates in Europe and other Western industrialized nations are lower, often much lower, than those in the U.S. In the U.S. itself, the 16 states that have abolished the death penalty generally have lower murder rates than those that retain it.

In the U.S., however, deterrence is not really the issue. Retribution is often seen as a more important justification for the death penalty. It is quite common for family members of the victim watch the execution of the person convicted of killing their relative, and afterwards to pronounce themselves satisfied that justice has been done ― it happened again with the execution of Troy Davis.

In the rest of the Western world, the desire to witness an execution is widely regarded as barbaric and barely comprehensible. The idea that the families of murder victims cannot obtain “closure” until the murderer has been executed seems not to be a universal human truth, but a product of a particular culture ― perhaps not even American culture as a whole, but rather the culture of the American South, where 80 percent of all executions take place.

In view of the possibility that Georgia recently executed an innocent man, it is particularly ironic that the South’s voters are America’s most zealous in their efforts to protect innocent human life ― as long as that life is still inside the womb, or is that of a person who, suffering from a terminal illness, seeks a doctor’s assistance in order to die when he or she wants. It is a contradiction that belies what the Republican Party, which dominates the region, promotes as a “culture of life.”

By Peter Singer

Peter Singer is a professor of bioethics at Princeton University and laureate professor at the University of Melbourne. His books include “Practical Ethics,” “The Expanding Circle” and “The Life You Can Save.” ― Ed.

(Project Syndicate)