Oklahoma’s bungled execution of convicted murderer Clayton Lockett on Tuesday was, in some ways, a medical experiment gone wrong.

In recent years, as pharmaceutical companies have halted sales of drugs used in executions, as legal challenges have mounted and medical groups have vowed to ostracize doctors who participate in sanctioned killings, states have found themselves winging it when it comes to carrying out lethal injections.

In their scramble to carry out death sentences, prison officials from different states have made secret handoffs of lethal-injection drugs. State workers have carried stacks of cash into unregulated compounding pharmacies to purchase chemicals for executions. Some states, like Oklahoma, have relied on unproven drug cocktails, all while saying they must conceal the source of the drugs involved to protect suppliers from legal action and harassment.

“It looks like a street-level drug deal,” said Dean Sanderford, a lawyer for Lockett. “And they’re keeping all the information secret from us. . . . They don’t need to be carrying out any more executions until they come clean, until we know exactly what happened with Clayton’s execution and everything about these drugs, where they’re getting them.”

This new era in death row improvisation has produced sometimes disturbing results, even before the debacle in Oklahoma, in which Lockett thrashed on a gurney before dying from an apparent heart attack after 43 minutes. Oklahoma’s corrections director said the vein line meant to administer lethal drugs into Lockett’s body had “exploded” and that the drugs were not having the intended effect.

With capital punishment dominating headlines, PostTV looks at the latest statistics on the death penalty in the United States, and in the 21 other countries that executed inmates in 2013. (Davin Coburn/The Washington Post)

The way Lockett and others have died has called into question the decades-old view that lethal injection is a more civil, more humane method of killing people than grisly alternatives such as the electric chair. Some states have pondered a return to firing squads and gas chambers, and others have steered away from executions altogether.

Forced to seek options

According to the nonprofit Death Penalty Information Center, 32 states and the federal government have the death penalty, and all use injection as their primary method of execution. Until 2010, most states still using lethal injection relied on a fairly standard three-drug protocol. The combination typically included an anesthetic such as sodium thiopental or pentobarbital, a paralyzing agent such as pancuronium bromide and a drug such as potassium chloride to stop the heart.

But events in recent years undermined that approach and left many states wrestling with moral and practical questions of how to carry out death sentences without violating the Constitution’s ban on “cruel and unusual” punishment.

In the spring of 2010, the American Board of Anesthesiologists decided to revoke the certification of any member who participated in a lethal injection, a move that could prevent an anesthesiologist from working in most hospitals. “We are healers, not executioners,” a group official said at the time. The American Medical Association long has said that participating in executions violates a doctor’s Hippocratic Oath.

Soon came a shortage of a critical drug used in most lethal injections. The sole U.S. company providing sodium thiopental announced in 2011 that it would stop selling the powerful anesthetic, citing objections from Italy, where the drug had been manufactured. State corrections officials sought to import the drug but the European Union banned the export of drugs used in executions, and U.S. officials seized some drugs at the border.

Many states, including Ohio and Oklahoma, switched primarily to another anesthetic drug, pentobarbital, which is used mostly for inducing comas in patients in cases of brain injury and is also used by veterinarians to anesthetize or euthanize animals. After a Danish manufacturer restricted its use in executions, some states sought out the drug from compounding pharmacies, which custom-mix small batches of drugs and whose products until recently have not been regulated by the Food and Drug Administration.

When supplies of pentobarbital began to run short, states turned to another more widely available drug, midazolam, which is often used to sedate surgery patients before they receive anesthesia, and which Oklahoma used for the first time in its lethal injection protocol Tuesday.

A new method’s troubles

Last October, Florida became the first state to put midazolam to the test on death row, despite worries from some experts that the drug might not produce a deep enough level of unconsciousness to prevent an inmate from feeling the pain that comes from the injections that follow.

Indeed, the Associated Press reported that convicted murderer and rapist William Happ “remained conscious longer and made more body movements after losing consciousness than other people executed recently by lethal injection under the old formula.” Court challenges followed from other Florida death row inmates, just as they have in a number of other states.

In January, midazolam was again in the spotlight. Ohio’s supply of pentobarbital expired and the state became the first to try midazolam as part of a two-drug injection cocktail, with the painkiller hydromorphone. Dennis McGuire, convicted of raping and murdering a 22-year-old pregnant woman, spent roughly 10 minutes alternately snorting and gasping for air after receiving the drug. His execution lasted almost half an hour — the longest since Ohio had resumed the death penalty in 1999.

A state investigation concluded that there was no evidence that McGuire “experienced any pain, distress or anxiety.” Officials insisted that the execution had been carried out in a humane and constitutional way and that McGuire felt no pain, despite the eyewitness accounts of his writhing on the table.

Even so, the state announced that when it carries out its next execution, it would use five times the dosage of the midazolam and also would increase the amount of hydromorphone. In the meantime, an attorney has filed suit on behalf of McGuire’s adult children, seeking an injunction against lethal injection in the state and challenging the use of drugs that had not been proven to work effectively in an execution.

States’ expertise questioned

“States are trying out new lethal-injection cocktails, and there is inadequate training and supervision and oversight of execution teams,” said David Waisel, an associate professor of anaesthesia at Harvard Medical School, who has testified for the defense in lethal-injection cases. “Given these recurring problems with lethal injections, if I had to be executed, I would choose a firing squad.”

Oklahoma Gov. Mary Fallin (R) announced Wednesday that she has ordered an independent review of the state’s execution procedures. She also said an independent pathologist will determine the precise cause of death for Lockett, who had shot a 19-year-old woman and ordered accomplices to bury her alive. Fallin issued a two-week stay of execution for Charles Warner, which had been scheduled to occur after Lockett’s on Tuesday night. Warner was convicted of raping and murdering his girlfriend’s 11-month-old baby.

The fact that there’s no settled, uniform way to conduct lethal injections, and that states have increasingly experimented in recent years with new and varied ways to kill the condemned, is a serious problem, said Deborah W. Denno, a death penalty expert and a professor at Fordham Law School.

“We have a dozen methods of lethal injection out there now,” Denno said. “[States] are not prepared to do this; they’re not knowledgeable to do this, and they don’t want to fess up to all the problems that are associated with something like this.”

She said that as states scramble to find drugs for lethal injections and tinker with different combinations and protocols for execution, they send a message that carrying out death sentences is more of a priority than resolving important ethical and legal questions.

“And that,” she said, “is not a good policy.”

Lindsey Bever and Mark Berman contributed to this report.