Until a court intervened last month, Nevada planned to execute an inmate here using fentanyl as part of a combination of drugs. (Courtesy the Nevada Department of Corrections/Courtesy the Nevada Department of Corrections)

The synthetic painkiller fentanyl has been the driving force behind the nation's opioid epidemic, killing tens of thousands of Americans last year in overdoses. Now two states want to use the drug's powerful properties for a new purpose: to execute prisoners on death row.

As Nevada and Nebraska push for the country's first fentanyl-assisted executions, doctors and death penalty opponents are fighting those plans. They have warned that such an untested use of fentanyl could lead to painful, botched executions, comparing the use of it and other new drugs proposed for lethal injection to human experimentation.

States are increasingly pressed for ways to carry out the death penalty because of problems obtaining the drugs they long have used, primarily because pharmaceutical companies are refusing to supply their drugs for executions.

The situation has led states such as Florida, Ohio and Oklahoma to turn to novel drug combinations for executions. Mississippi legalized nitrogen gas this spring as a backup method — something no state or country has tried. Officials have yet to say whether it would be delivered in a gas chamber or through a gas mask.

Other states have passed laws authorizing a return to older methods, such as the firing squad and the electric chair.

"We're in a new era," said Deborah Denno, a law professor at Fordham University. "States have now gone through all the drugs closest to the original ones for lethal injection. And the more they experiment, the more they're forced to use new drugs that we know less about in terms of how they might work in an execution."

Supporters of capital punishment blame critics for the crisis, which comes amid a sharp decline in the number of executions and decreasing public support for the death penalty. States have put 23 inmates to death in 2017 — the second-fewest executions in more than a quarter-century. Nineteen states no longer have capital punishment, with a third of those banning it in the past decade.

"If death penalty opponents were really concerned about inmates' pain, they would help reopen the supply," said Kent Scheidegger of the Criminal Justice Legal Foundation, which advocates for the rights of crime victims. Opponents "caused the problem we're in now by forcing pharmaceuticals to cut off the supply to these drugs. That's why states are turning to less-than-optimal choices."

Prison officials in Nevada and Nebraska have declined to answer questions about why they chose to use fentanyl in their next executions, which could take place in early 2018. Many states cloak their procedures in secrecy to try to minimize legal challenges.

But fentanyl offers several advantages. The obvious one is potency. The synthetic drug is 50 times more powerful than heroin and up to 100 times more powerful than morphine.

"There's cruel irony that at the same time these state governments are trying to figure out how to stop so many from dying from opioids, that they now want to turn and use them to deliberately kill someone," said Austin Sarat, a law professor at Amherst College who has studied the death penalty for more than four decades.

Another plus with fentanyl: It is easy to obtain. Although the drug has rocketed into the news because of the opioid crisis, doctors frequently use it to anesthetize patients for major surgery or to treat severe pain in patients with advanced cancer.

Nevada officials say they had no problem buying fentanyl.

"We simply ordered it through our pharmaceutical distributor, just like every other medication we purchase, and it was delivered," Brooke Keast, a spokeswoman for the Nevada Department of Corrections, said in an email. "Nothing out of the ordinary at all." 

The state, which last put someone to death in 2006, had planned its first fentanyl-assisted execution for November. The inmate involved, 47-year-old Scott Dozier, was convicted of killing a man in a Las Vegas hotel, cutting him into pieces and stealing his money.

According to documents obtained by The Washington Post, Nevada's protocol calls for Dozier first to receive diazepam — a sedative better known as Valium — and then fentanyl to cause him to lose consciousness. Large doses of both would cause a person to stop breathing, according to three anesthesiologists interviewed for this report.

Yet Nevada also plans to inject Dozier with a third drug, cisatracurium, to paralyze his muscles — a step medical experts say makes the procedure riskier.

"If the first two drugs don't work as planned, or if they are administered incorrectly, which has already happened in so many cases . . . you would be awake and conscious, desperate to breathe and terrified but unable to move at all," said Mark Heath, a professor of anesthesiology at Columbia University. "It would be an agonizing way to die, but the people witnessing wouldn't know anything had gone wrong because you wouldn't be able to move."

John M. DiMuro, who helped create the fentanyl execution protocol when he was the state's chief medical officer, said he based it on procedures common in open-heart surgery. He included cisatracurium because of worries that the Valium and fentanyl might not fully stop an inmate's breathing, he said. "The paralytic hastens and ensures death. It would be less humane without it."

A judge postponed Dozier's execution last month over concerns about the paralytic, and the case is awaiting review by Nevada's Supreme Court. In the meantime, Nebraska is looking toward a fentanyl-assisted execution as soon as January. Jose Sandoval, the leader of a bank robbery in which five people were killed, would be the first person put to death in that state since 1997.

Sandoval would be injected with the same three drugs proposed in Nevada, plus potassium chloride to stop his heart.


Nebraska and Nevada are trying to move forward with executions using fentanyl. Jose Sandoval, left, would be put to death in Nebraska. Scott Dozier would be executed in Nevada. (Nati Harnik/AP, Ken Ritter/AP/Nati Harnik/AP, Ken Ritter/AP)

Even at much lower concentrations, intravenous potassium chloride often causes a burning sensation, according to Heath. "So if you weren't properly sedated, a highly concentrated dose would feel like someone was taking a blowtorch to your arm and burning you alive," he said.

Fentanyl is just the latest in a long line of approaches that have been considered for capital punishment in the United States. With each, things have often gone wrong.

When hangings fell out of favor in the 19th century — because of botched cases and the drunken, carnival-like crowds they attracted — states turned to electrocution. The first one in 1890 was a grisly disaster: Spectators noticed the inmate was still breathing after the electricity was turned off, and prison officials had to zap the man all over again.

Gas chambers were similarly sold as a modern scientific solution. But one of the country's last cyanide gas executions, in 1992, went so badly that it left witnesses crying and the warden threatening to resign rather than attempt another one.

Lethal injection, developed in Oklahoma in 1977, was supposed to solve these problems. It triggered concerns from the start, especially because of the paralytic drug used. Even so, the three-drug injection soon became the country's dominant method of execution.

In recent years, as access to those drugs has dried up, states have tried others. Before the interest in fentanyl, many states tested a sedative called midazolam — leading to what Supreme Court Justice Sonia Sotomayor called "horrifying deaths."

Dennis McGuire, who raped and killed a pregnant newlywed in Ohio, became the first inmate on whom that state's new protocol was tried. Soon after the 2014 execution began, his body writhed on the table as he gasped for air and made gurgling, snorting noises that sounded as though he was drowning, according to witnesses.

The same year, Oklahoma used midazolam on an inmate convicted of kidnapping and killing a teenager; authorities aborted the execution after Clayton Lockett kicked, writhed and grimaced for 20 minutes, but he died not long after. Three months later, Arizona used midazolam on Joseph R. Wood III, who was convicted of killing his ex-girlfriend and her father. Officials injected him more than a dozen times as he struggled for almost two hours.

Like those in other states, Arizona officials argued that the inmate did not suffer and that the procedure was not botched. Later, they said they would never again use midazolam in an execution.

Joel Zivot, a professor of anesthesiology and surgery at Emory University, called the states' approach ludicrous. "There's no medical or scientific basis for any of it," he said. "It's just a series of attempts: obtain certain drugs, try them out on prisoners, and see if and how they die."

The bad publicity and continuing problems with drug supply have sent some of the 31 states where capital punishment remains legal in search of options beyond lethal injection. Turning to nitrogen gas would solve at least one issue.

"Nitrogen is literally in the air we breathe — you can't cut off anyone's supply to that," said Scheidegger, who strongly supports the idea.

In addition to Mississippi, Oklahoma has authorized nitrogen gas as a backup to lethal injection. Corrections officials and legislators in Louisiana and Alabama have said they hope to do the same.

And yet, critics note, there is almost no scientific research to suggest that nitrogen would be more humane.

Oklahoma's legislature approved nitrogen gas in 2015 based on a report solicited from three professors at a local university, none of whom had any medical or scientific background. They cited examples of airplane pilots passing out from nitrogen hypoxia and accounts of people killing themselves using nitrogen and helium gas. A financial analysis prepared for lawmakers said the approach would be "relatively cost effective," requiring only a gas mask and a container of nitrogen.

Zivot is among those skeptical that nitrogen would work as hoped.

"There's a difference between accidental hypoxia, like with pilots passing out, and someone knowing you're trying to kill him and fighting against it," he said. "Have you ever seen someone struggle to breathe? They gasp until the end. It's terrifying."

Dozier, the inmate Nevada hopes to execute soon with fentanyl, has said he would prefer death by firing squad over any other method. In more than a dozen interviews, many experts on both sides of the issue expressed similar views.

Of all the lethal technology humans have invented, the gun has endured as one of the most efficient ways to kill, said Denno, who has studied the death penalty for a quarter-century.

"The reason we keep looking for something else," she said, "is because it's not really for the prisoner. It's for the people who have to watch it happen. We don't want to feel squeamish or uncomfortable. We don't want executions to look like what they really are: killing someone."

Julie Tate contributed to this report.