A man executed in Alabama heaved and coughed for 13 minutes before dying, raising ire over a drug critics have said should be banned. (Reuters)

An Alabama inmate heaved and coughed during his execution Thursday night, a lethal injection process that lasted for more than half an hour, according to media witnesses.

The lethal injection came after a deadlocked U.S. Supreme Court decided not to step in, but with four of the eight justices saying they would have stayed the execution, one shy of the number needed to halt the process.

Ronald Bert Smith Jr., 45, was sentenced to death for killing Casey Wilson, a convenience-store clerk, during a robbery in 1994, according to court records. Prosecutors said that Smith pistol-whipped Wilson, shot him and then returned to shoot the clerk again, killing him.

During the lethal injection, Smith was apparently struggling for breath as he heaved and coughed for about 13 minutes, wrote Kent Faulk of AL.com, one of the media witnesses. Smith also clenched his fist after being given the first drug, Faulk wrote.

This account was echoed by an Associated Press reporter also serving as a media witness, who wrote that Smith appeared to move during tests meant to assess his consciousness.

“There will be an autopsy that will be done on Mr. Smith,” Jefferson Dunn, commissioner of the Alabama Department of Corrections, said in a briefing after the execution. “And if there were any irregularities or anything, then that would be shown, borne out, in the autopsy.”

Dunn said that officials “followed the protocol according to the way it is written” and that there were two attempts to assess Smith’s consciousness during the execution. While the media witnesses wrote that they saw Smith appear to move after the second assessment, Dunn said he saw no reaction.

Smith was pronounced dead at 11:05 p.m., Dunn said. Smith did not make a final statement, and Wilson’s relatives also declined to give a statement, Dunn said.

Alabama uses a combination of three drugs during executions. Although the state corrections department considers its execution protocol confidential, a spokesman has confirmed to The Washington Post that it uses midazolam and two other drugs during lethal injections.

In response to a years-long shortage of lethal-injection drugs, prompted in part by European opposition to the death penalty, which halted a supply of the chemicals, states have altered their execution protocols to adopt new drug combinations.

Midazolam, a sedative used in Smith’s execution, has been used in several executions in recent years that either took longer than normal or were apparently bungled. In Oklahoma, an inmate writhed and grimaced in 2014 before dying; an investigation later found issues with the IV insertion. That same year, an Arizona inmate’s execution took nearly two hours as he gasped for air and struggled to breathe, while an Ohio inmate took 30 minutes to die.

Last year, the Supreme Court heard a case involving Oklahoma’s use of midazolam after those high-profile executions. The justices upheld use of the drug, but they were bitterly divided on both that case and larger questions regarding the death penalty.

Supreme Court Justice Clarence Thomas. (Cliff Owen/AP)

The Supreme Court’s decision not to stay Smith’s execution Thursday came a month after the shorthanded court halted the execution of Thomas Arthur, another inmate in Alabama, by a thin margin. Four justices in that case said they thought it warranted a stay, and Chief Justice John G. Roberts Jr. said he would vote with them as a courtesy. (The four justices were not identified in the court’s order at the time, but it is likely they were the same four justices who would have granted the stay Thursday for Smith.)

It takes four votes on the court to accept a case for review but five to grant a stay. Roberts’s vote last month meant that Arthur remained alive while the court considered whether to review his case and the question about the Alabama death penalty he posed.

There was no such “courtesy” vote Thursday night in Smith’s case, and the justices did not provide explanations for their decisions. Supreme Court Justice Clarence Thomas — the justice assigned to the 11th Circuit, which includes Alabama — denied the last stay request shortly before 10:30 p.m. Eastern time. Smith was pronounced dead a little more than 90 minutes later.

Last-minute attempts to have the Supreme Court prevent executions are expected. But the frantic and unsuccessful effort Thursday to save Smith may have revealed something about the court and the unwillingness of conservative justices to even temporarily spare those on death row.

At one point Thursday evening, the Supreme Court denied the stay, but the four liberal justices — Ruth Bader Ginsburg, Stephen G. Breyer, Sonia Sotomayor and Elena Kagan — all said they would have granted that request.

They did not give a reason, but apparently wanted more time to consider Smith’s claim that Alabama’s death penalty system held at least as many constitutional problems as the Florida statute the Supreme Court voided last term. Both states did not give the final decision on whether to impose a death penalty to the jury.

A jury in Alabama had voted to give Smith life in prison, rather than a death sentence, by a vote of 7 to 5, but the judge overruled that and sentenced him to death. Attorneys for Smith argued in Supreme Court filings against that death sentence based on the judge overruling the jury, but Alabama prosecutors rejected those claims, saying that Smith should be executed for the “extraordinarily brutal” killing.

Smith’s attorneys said Thursday that “the Court should not permit executions in the face of four dissents,” stating that “the Court’s inconsistent practices respecting 5-4 stay denials in capital cases clash with the appearance and reality both of equal justice under law and of sound judicial decision-making.”

Other people have been executed despite four justices voting to spare them. But the court’s action raised the question of why Arthur received the stay but not Smith. As is the court’s custom, it was not explained.

William Baude, a University of Chicago law professor and former clerk to Roberts, calls such decisions without accompanying reasoning the court’s “shadow docket.”

Baude offered several possibilities for Thursday’s lack of a “courtesy fifth.” Perhaps in the intervening month, the justices closely reviewed Arthur’s case, and decided there is no need to accept it. Or that the courtesy fifth was a one-time experiment that for some reason is not going to continue. Or that justices felt more strongly about Arthur’s case than Smith’s.

One final reason might be the presidential election that occurred in the interim, Baude wrote in an opinion piece in The Washington Post that published Friday morning. Baude said some have speculated that Roberts had been repaying Breyer for a courtesy fifth vote he supplied to stay a ruling that a Virginia school district must allow a transgender student to use the bathroom that matches his gender identity. At the time, it looked as if Hillary Clinton would become president, and shift the court’s majority to liberals. A favor to Breyer might have helped the chief justice in the future.

Such a scenario is not particularly flattering for the court, Baude said. But when the justices act without explaining their reasoning, he said, “it leaves us all to darker speculations.”

Smith’s attorneys had pointed to the Supreme Court decision early this year to strike down Florida’s death penalty as unconstitutional because it let judges, rather than juries, make the final call on death sentences. The decision has thrown Florida’s death penalty system, which includes the country’s second-largest death row, into disarray. Florida lawmakers rewrote their state’s death penalty statute in response to the high court’s ruling, but in October, the Florida Supreme Court struck down the new statute as unconstitutional.

Alabama — which, like Florida, is among the country’s modern leaders in capital punishment — lets judges overrule a finding by juries about whether convicted people should be put to death. An Alabama inmate earlier this year had argued that the state’s system was “virtually identical” to the earlier system struck down in Florida. The U.S. Supreme Court denied Christopher Brooks’s appeals, and he was executed in January, the state’s only other execution this year.

Alabama Attorney General Luther Strange has insisted his state’s system was unaffected by the Florida ruling, and in September, the Alabama Supreme Court upheld the death penalty there as constitutional.

After Smith’s execution, Strange released a statement saying the man had “avoided justice for the coldblooded murder” of Wilson.

“The trial court described Smith’s acts as ‘an execution-style slaying,’” Strange said. “Tonight, justice was finally served.”

Smith was the 20th person executed in the United States this year.

Further reading:

For the first time in decades, fewer than 50 percent of Americans back the death penalty

Nebraska and California voters decide to keep the death penalty

Connecticut Supreme Court says no death penalty for remaining death-row inmates

This story has been updated to add additional information.