Updated at 1:47 p.m. ET, Saturday

A federal judge in Arkansas has halted the execution of seven men beginning Monday night, throwing another wrench into the state's plans to carry out the executions before its lethal injection drugs expire.

U.S. District Judge Kristine Baker ordered the preliminary injunction early Saturday, reports the Arkansas Democrat-Gazette. This ruling came less than 24 hours after the state's supreme court stayed one execution, and a county court delayed the rest.

The Democrat-Gazette cites Baker as writing, "there is a significant possibility that plaintiffs will succeed on the merits of their Eighth Amendment challenge to Arkansas's lethal injection protocol."

The paper goes on to report:

"Baker issued the ruling after presiding over a four-day trial on a case filed by the seven men. They were set to be executed two at a time between Monday and April 27, with lethal injections scheduled on consecutive Mondays and Thursdays. ..."The inmates' attorneys sought to temporarily block the executions, arguing that the compressed schedule increases the likelihood of potentially harmful mistakes. The quick pace also prevented the men from preparing an adequate defense, which violates their federal due-process rights, the lawyers argued."Arkansas has not executed an inmate since 2005 due to both legal challenges and difficulty in maintaining a drug supply. Gov. Asa Hutchinson set the 11-day schedule as the expiration of one of the drugs in the state's three-drug lethal cocktail neared. Midazolam, set to expire at the end of April, is an anesthetic given before the injection of fatal drugs."

Later on Saturday, Hutchinson released a statement acknowledging the timeline for the executions "would trigger" the cases but expressed optimism that expediency would prevail in the matter.

"I expect both the Supreme Court of Arkansas and the 8th Circuit Court of Appeals to review the decisions quickly, and I have confidence in the Attorney General and her team to expedite the reviews," Hutchinson's statement reads.

Before Baker's injunction, Pulaski County Judge Wendell Griffen had issued a broader temporary restraining order following an earlier one Friday by the Arkansas Supreme Court, which had stayed the execution of Bruce Ward. According to his attorney, Scott Braden, Ward is mentally ill and "has no rational understanding of the punishment he is slated to suffer or the reason why he is to suffer it."

Braden also states:

"We are grateful that the Arkansas Supreme Court has issued a stay of execution for Bruce Ward so that they may consider the serious questions presented about his sanity. He deserves a day in court for that, but in Arkansas the rules do not permit that. Instead, they give the power to director of the department of corrections to decide whether the department can execute someone or not. That is both unfair and unconstitutional."

The other inmates had argued that the speed with which the executions were to go forward trampled on their rights, stunting clemency proceedings and causing them undue suffering.

Last week U.S. District Judge D. Price Marshall Jr. proved receptive to that argument, ruling that the original schedule did not allow enough time for the clemency petition of one of the death-row inmates, Jason McGehee, to proceed.

Since a parole board recently recommended clemency for McGehee, Marshall said the schedule prevented carrying out the 30-day comment period on McGehee's petition.

As NPR's Camila Domonoske noted, the ruling bumps McGehee's execution past the end-of-April expiration date for its supply of midazolam, one of the drugs in the state's lethal injection cocktail.

The drugs themselves have been in dispute, as well.

On Thursday night, the medical supplier McKesson issued a statement objecting to the manner in which the state obtained its vecuronium bromide, another of the three drugs in the cocktail. McKesson supplies the drug — which is produced by Hospira and its parent company, Pfizer — to pharmacies, hospitals and other organizations.

"The Arkansas Department of Correction intentionally sought to circumvent McKesson's policies to procure Pfizer's vecuronium bromide under the auspices that it would be used for medical purposes in ADC's health facility," McKesson said in its statement.

The company says that it tried multiple times to get the state to offer assurances the drug won't be used in lethal injections or simply to get the drug returned, and that McKesson even refunded the cost, but the state did not comply.

So, McKesson says, "it is considering all possible means by which to secure the return of the product, up to and including legal action."

The Associated Press explains that "under Arkansas' protocol, midazolam is used to sedate the inmate, vecuronium bromide then stops the inmate's breathing and potassium chloride stops the heart."

According to the wire service, Pfizer says the vecuronium bromide was sold to Arkansas without Pfizer's knowledge, while Fresenius Kabi USA and West-Ward Pharmaceuticals Corp. — the presumed makers of the state's supply of potassium chloride and midazolam, respectively — also filed a friend of the court brief in the inmates' case, "objecting to their drugs' use in the executions."

Arkansas Gov. Asa Hutchinson has defended the timeline of the executions, citing the expiration date of the state's supply of midazolam.

"One of the three drugs in the lethal injection protocol expires at the end of April," Hutchinson said in a statement emailed to NPR last month. "In order to fulfill my duty as Governor, which is to carry out the lawful sentence imposed by a jury, it is necessary to schedule the executions prior to the expiration of that drug."

He says that despite the compressed execution schedule, the inmates have in some cases already received "decades of review."

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