NORMAN, Okla. — Oklahoma plans to resume putting inmates to death using lethal injection drugs, five years after officials halted all executions in the wake of a series of botched procedures that drew national attention to the state’s death penalty protocol.
Officials in Oklahoma, one of the country’s most prolific death penalty states, said on Thursday that they now have access to the drugs necessary to carry out capital punishment, though when the next execution would be scheduled remained unclear. It would be the first execution in Oklahoma since a string of errors and problematic executions in 2014 and 2015 that President Barack Obama had described as “deeply troubling.”
“I believe capital punishment is appropriate for the most heinous of crimes, and it is our duty as state officials to obey the laws of the state of Oklahoma by carrying out this somber task,” the Republican governor, Kevin Stitt, told reporters at a news conference in Oklahoma City.
Two state agencies — the attorney general’s office and the Department of Corrections — have been working to revise Oklahoma’s execution protocol and to establish a reliable source of lethal injection drugs, and Mr. Stitt and other officials expressed confidence that the state would be able to go forward without new problems.
The state said it had no plans to change the three-drug sequence that it used in its execution protocol before the moratorium: midazolam, a short-acting sedative; vecuronium bromide, which stops breathing; and potassium chloride, which stops the heart.
“The additions that we’ve made to the protocol simply add more checks and balances, more safeguards to the system, to ensure that what has happened in the past won’t happen again,” the Oklahoma attorney general, Mike Hunter, said Thursday.
Mistakes in administering and overseeing the drug supply were among the factors that led to problems in the state’s last two executions.
The first of these was in 2014 at the state prison in McAlester, Okla., when Clayton D. Lockett appeared to moan and struggle during a procedure that took 43 minutes. Doctors concluded that Mr. Lockett had not been fully sedated; he regained consciousness during the process and writhed in pain before he died, long after witnesses, including members of the news media, had been escorted from the death chamber’s viewing room.
Then in January 2015, Charles F. Warner was put to death in an 18-minute execution in which officials mistakenly used the wrong drug to stop his heart. Later in 2015, Richard E. Glossip, a death row inmate who challenged the constitutionality of Oklahoma’s lethal injection protocol before the Supreme Court, was granted a stay of execution after the state’s supplier of lethal injection drugs sent prison officials the wrong drug.
In both of the 2015 cases, the drug supplier unexpectedly substituted potassium acetate for the heart-stopping drug potassium chloride. In Mr. Glossip’s case, officials did not notice the mistake until they opened the box two hours before he was set to die.
It was that case that prompted state officials to order a moratorium on all executions until the state’s death penalty procedures could be reviewed.
“Until we have complete confidence in the system, we will delay any further executions,” the Republican governor at the time, Mary Fallin, said in 2015.
That decision was later backed by a federal judge in Oklahoma, who ordered the state to stop executions until the protocol was revised. Mr. Stitt and other officials said on Thursday that the court-ordered moratorium would end in 150 days. After that, the state’s use of lethal injections will resume and officials will begin the process of carrying out the first execution since Mr. Warner’s in 2015, officials said.
The move by Oklahoma’s leaders is likely to be challenged in court by lawyers representing death row inmates. Dale A. Baich, one of Mr. Glossip’s lawyers, said he planned to ask a federal court to resume hearing a lawsuit on the use of midazolam, filed several years ago, that had been put on hold during the moratorium on executions.
“Oklahoma’s history of mistakes and malfeasance reveals a culture of carelessness around executions that should give everyone pause,” Mr. Baich said.
Oklahoma and other death penalty states have had problems in recent years not only administering lethal injections, but also acquiring execution drugs. States have been scrambling to obtain the drugs and trying new combinations in the face of shortages as manufacturers have ceased production or prohibited the use of their products in executions.
That scramble has caused some states, including Oklahoma, to consider more antiquated ways putting inmates to death. Tennessee is allowing prison officials to use the electric chair if lethal injection drugs are unavailable.
In Oklahoma, lawmakers approved a backup execution procedure — to be used only if lethal drugs cannot be acquired — involving the use of nitrogen gas. Although the law does not specify how the gas should be administered, a state study in 2014 proposed covering a condemned inmate’s head with a bag that would slowly fill with nitrogen gas. Supporters likened it to the experience of pilots flying too high into the atmosphere and losing consciousness, while critics called it barbaric.
“Ensuring we have an alternative is just being responsible,” said Mr. Hunter, the attorney general.
Of the 47 inmates on Oklahoma’s death row, 26 have exhausted their appeals and are awaiting an execution date.
Mr. Glossip, who remains on death row and whose case has attracted support from celebrities and death penalty opponents who believe he is innocent, is the next inmate in line to be executed. He was convicted in the 1997 murder of Barry Van Treese, the owner of the Best Budget Inn in Oklahoma City, where Mr. Glossip was the manager.
Prosecutors said Mr. Glossip persuaded a 19-year-old man, Justin Sneed, to kill Mr. Van Treese in return for thousands of dollars in motel revenues. Mr. Sneed admitted to beating Mr. Van Treese to death with a baseball bat but said he was pressured by Mr. Glossip. He is serving a sentence of life without parole.
Mr. Glossip’s lawyers have questioned Mr. Sneed’s credibility and produced statements from two men who served time with him, one of whom said Mr. Sneed had boasted of “setting up” Mr. Glossip.
Graham Lee Brewer reported from Norman, and Manny Fernandez from Houston.