It sounds like a very bad joke: Oklahoma prison staff were unsuccessful in trying to carry out an execution last week, but the condemned man died. Capital punishment in America, which has produced many cautionary moments, this time produced a gruesome, shocking farce.

Clayton Lockett was a despicable person. When 19-year-old Stephanie Nieman resisted his effort to steal her truck, Lockett and two other men beat her, covered her mouth with duct tape, sexually assaulted her and forced her to dig her own grave. Lockett then shot her twice and buried her alive.

Even though he deserved no sympathy, it’s hard not to feel soiled by the specter of the state horribly mangling his execution. Personnel couldn’t find a suitable vein in his arms, legs or feet to insert the needle that would deliver the lethal cocktail. Finally, they put a catheter into his groin, but something went awry. Lockett began writhing on the table, moved his head back and forth, tried to sit up and cried out.

Not enough of the drugs had been delivered to cause death, an attending doctor reported, and not enough were left to allow another attempt. The execution was halted - but minutes later, Lockett suffered a heart attack that finished the job.

The warden asked the governor for permission to postpone a second execution that was scheduled for the same evening, and it was granted. Corrections Director Robert Patton later recommended an independent investigation to identify the causes of the problems in this instance, as well as a full review of execution procedures.

Public support for capital punishment has declined in recent years, and scenes like this one are one reason. Another reason is that so many people have been wrongly convicted of capital offenses. More than 140 inmates sentenced to die have been exonerated, according to the Innocence Project.

And some of the guilty are subjected to agony. A 2007 study by University of Miami scientists concluded that the mix of drugs used for lethal injections may cause intense pain and slow death, instead of the quick, painless end it is supposed to provide. In the worst case, one of the researchers said, “It would sort of be the equivalent of slowly suffocating while being burned alive.”

“We started with hangings, then moved to electrocution in 1890 and to lethal gas in 1921, with the firing squad always around on the outskirts,” Deborah Denno, a law professor at Fordham University, told The New York Times. “The move to lethal injection in 1977 was an effort to combat all the ills associated with other methods. Nevertheless, we’ve seen botch after botch.”

The U.S. Constitution forbids punishments that are “cruel and unusual,” but what was inflicted on Lockett was plainly both. There is no way to administer the death penalty without a serious risk of grotesque brutality, fatal errors or both. Life imprisonment without the chance of parole for the most heinous criminals is a significant punishment that carries fewer perils and protects the public.

Three years ago, Illinois abolished the death penalty. This page supported that effort. Aside from the sobering number of wrongful convictions, the capital punishment process is hugely expensive, time-consuming and seems to have little deterrent effect on crime. The spectacle of prison personnel unintentionally inflicting horror and pain, clumsily killing someone, is more cause to end the practice.

What happened to Clayton Lockett has prompted a review of procedures by Oklahoma. It may prompt review by other states that have capital punishment. But rather than review how it is done, lawmakers in those states should ask themselves: How can government be trusted to impose death as punishment? The answer is, government cannot.

This editorial appeared in the Chicago Tribune on Wednesday.