Missouri on Tuesday carried out the country’s first execution amid the coronavirus pandemic, not long after the U.S. Supreme Court rejected a request to stop the lethal injection.

In an order issued late Tuesday afternoon, the court said it was denying the application filed by Walter Barton, who was convicted of killing an elderly acquaintance in 1991. There were no noted dissents. About two hours later, Barton was pronounced dead, according to the Missouri Department of Corrections.

Several planned executions — which typically require packing people into small rooms to bear witness — have been delayed since early March, when the deadly virus shut down large swaths of the United States. Outbreaks have been a particular concern in prisons and jails across the country. 

The case in Missouri wound through the legal system for nearly three decades, dating to the 1991 stabbing death of Gladys Kuehler, an 81-year-old who managed a mobile home park in Ozark, Mo. Barton was arrested that year, leading to five trials stretching out over the next quarter-century. 

Barton long argued he was innocent, and his attorney on Monday asked the Supreme Court to stay his execution. In response, Missouri officials said his claims are “plainly meritless” and called for the execution to proceed as scheduled — albeit with some safety adjustments for witnesses.

The nation’s last execution was March 5, when Alabama carried out Nathaniel Woods’s death sentence.

Texas, the country’s most active death penalty state, has halted several executions since Gov. Greg Abbott (R) declared an emergency there in March.

The Tennessee Supreme Court also pushed back an execution set for this summer after the condemned inmate sought a delay due to the pandemic. It’s been rescheduled for February. Attorneys for another Tennessee inmate with an execution scheduled for October have petitioned the same court for a delay, arguing that they cannot properly prepare for a competence hearing this summer due to the pandemic. 

Barton’s attorneys said they, too, were hobbled by the outbreak. They wrote in court filings that, because of the pandemic, “preparation efforts have been slowed to a crawl in critical ways by travel and meeting restrictions which have been imposed.” Among other things, they said, the restrictions hindered attempts to find and interview more jurors. 

Court filings detail how the first two attempts to prosecute Barton ended with mistrials, while the next two produced guilty verdicts and death sentences that were later tossed.

In 2006, prosecutors moved ahead with a fifth trial that ended with Barton being found guilty and sentenced to death. 

An attorney for Barton argued in court filings that while Kuehler’s blood was found on Barton’s clothing — which he attributed to slipping after her body was discovered — an expert concluded the stains did not match “the number and kinds of wounds inflicted.” In response, the office of Eric Schmitt, Missouri’s attorney general, says it was Barton’s attorney who decided against using that blood-spatter expert as part of his defense. 

Barton’s attorney argued against the use of a jailhouse informant who had been found to lie during the trial about her criminal history. He also cited an expert’s conclusion that Barton is not competent to be executed.

In its filing to the Supreme Court, Schmitt’s office said that information Barton’s attorneys are raising now has been known since he was on trial in 2006 and that there is “no valid justification” for not bringing them up sooner. 

“Such last-minute claims do not warrant a stay of execution after many years of direct and collateral review testing the sufficiency of Barton’s conviction and sentence,” the filing states. Quoting from a divided Supreme Court ruling against a Missouri death-row inmate last year, Schmitt’s office added: “Both the State of Missouri and Missouri crime victims ‘deserve better.’ ”

The Innocence Project and other groups had called for an independent board to evaluate Barton’s conviction, arguing that his case “has the hallmarks of a wrongful conviction” in their plea.

“It is unconscionable that Mr. Barton’s execution was allowed to go forward given the well-known problems with the evidence at the basis of his conviction without a deep examination into his innocence,” Vanessa Potkin, director of post-conviction litigation at the Innocence Project and one of the letter’s signatories, said in a statement after he was executed. 

Because of the coronavirus, the Missouri Department of Corrections had planned to divide witnesses within three rooms. Karen Pojmann, a spokeswoman for the department, said everyone would be given a temperature check before entering and provided face coverings and hand sanitizer.