In revolutionary France in the early 1790s, physician Joseph-Ignace Guillotin proposed that a surefire execution mechanism be used to carry out the death penalty for the state. Historians believe that Guillotin suggested the use of the instantaneous decapitation device that would later bear his name as a humane form of capital punishment. The guillotine was thought to bring quick mortality more reliably than the standard methods of prerevolutionary France—beheading by sword or ax, which sometimes involved repeated blows, or hanging by a noose, which could take several minutes or even longer.

In the U.S. in the late 1970s, Oklahoma state medical examiner Jay Chapman developed a fail-safe execution method that many states soon adopted as their main form of capital punishment. Lethal injection, in which three poisonous chemicals are administered to the condemned, largely replaced execution by hanging, firing squad, gas chamber and electric chair, each of which had at some point been judged to be inhumane or excessively violent.

Yet this method is far from foolproof. According to reports, unskilled executioners have caused prolonged suffering in the condemned by mishandling the deadly drug jabs—instances in which they missed veins, used blocked IVs or miscalculated doses, leading to failed anesthesia and chemical burns. Meanwhile ethical prohibitions to the participation of trained medical personnel (“Do no harm...”) have mostly kept the amateurs and their ad hoc methods on the job. In recent months, however, news of numerous botched lethal injections has led courts and state governments to place moratoriums on the practice in a third of the 38 U.S. states that have the death penalty.

In the meantime, some researchers have challenged the assumed airtight efficacy of the drug protocols used in most American lethal injections. The authors of two papers published in Lancet and PLoS Medicine in recent years have questioned whether the recommended protocols, even if carried out as prescribed, would produce death without unnecessary or gratuitous pain—the “cruel and unusual punishment” forbidden by the Eighth Amend­ment to the U.S. Constitution. Although some critics argue that the studies are flawed, the dearth of research on lethal injection merely highlights our limited knowledge of the procedure.

The generally accepted approach relies on introducing into the sentenced criminal’s bloodstream a chemical cocktail consisting of a barbiturate to bring on sedation and suppress respiration, a neuromuscular paralytic to halt breathing and body convulsions, and a potassium electrolyte to stop the heart. The intent of the mixture is to provide toxic redundancy so that each drug alone would bring on death. Dosages remain the same whether the condemned weighs 150 pounds or twice that. Scientists have found that, as a result, there have been instances in which breathing has continued, the heart beat on, or nerves remained undeadened despite the injections.

In veterinary medicine, the federal government and professional associations keep data on animal euthanasia and have developed guidelines and procedures in accord with the research. Obviously, the same cannot be done for human execution techniques. It would help, however, if states released their data on lethal injections: only two have done so, leaving scientists able to analyze only 41 of the 904 lethal injections that have been conducted in the U.S. (at press time). More complete information would surely help society surmount the lingering uncertainties regarding the deadly protocol and its application.

For those of us who already believe capital punishment is wrong, this situation is just one more outrage. But even those who disagree would have to acknowledge that the Constitution holds that the state must not execute people cruelly. Perhaps capital punishment can never be anything but inhumane, but until society is willing to accept that principle, it is obliged to execute as humanely as it can. Certainly some ways of killing are less cruel than others. So what can and must government do to be more humane? Clearly, the time has come for renewed public discussion and consideration of the death penalty, including all its distasteful details.