The men are claimed to have mental health problems, and the United States Supreme Court is due to hear oral arguments next week in a case involving a defendant's right to access independent mental health experts during their tiral. The state supreme court granted the stays in light of the pending federal case.

Arkansas appealed the stay on Davis, but did not pursue Ward's case.

In the early hours of April 18, the US Supreme Court denied Arkansas' application to vacate the stay on Davis' execution.

Neither of the men were put to death.

On Monday the Arkansas Supreme Court also made two decisions relating to Pulaski County Circuit Judge Wendell Griffin and his decisions.

Griffin had on April 14 ruled that the state's supply of vecuronium bromide, an anesthetic which induces paralysis and which is the second of the state's three-drug lethal injection protocol, could not be used in the process.

The drug supplier, McKesson Medical-Surgical Inc., had stated that the drug manufacturer prohibits vecuronium for use in executions, and that Arkansas had purchased it under false pretenses. McKesson discovered that the drug was to be used for executions and demanded the state return the drug, promising a refund. The supplier said it refunded the state, which never returned the drug.

However, Griffin also attended a protest against capital punishment outside the governor's mansion on Friday.

On Monday, the Arkansas Supreme Court forbade Griffin from hearing death penalty-related cases, and referred him to the Arkansas Judicial Discipline and Disability Commission to discover if he violated a state code of judicial conduct.

It also vacated Griffin's restraining order against the state's use of vecuronium bromide.

Meanwhile, the United States Court of Appeals for the Eighth Circuit vacated April 17 a federal judge's preliminary stay of executions which had been handed down April 15.

Federal judge Kristine G. Baker had ruled that the use of midazolam, a sedative, may violate the constitutional ban on cruel and unusual punishments.

The sedative has been used in botched executions, and some medical experts have claimed it is not proven to be effective, thus exposing an inmate to the risk of severe pain as the other drugs are administered.

The eighth circuit appeals court rejected Baker's determination that the executions should be delayed to give courts time to consider whether the use of midazolam is a breach of the Eighth Amendment. The appellate judges wrote that “the equivocal evidence recited by the district court falls short of demonstrating a significant possibility that the prisoners will show that the Arkansas protocol is 'sure or very likely' to cause severe pain and needless suffering.”

One appellate judge dissented from the eighth circuit's decision.

After the US Supreme Court declined to reverse the stay on Davis' execution, Governor Asa Hutchinson, a Republican, stated: “I am disappointed in this delay for the victim’s family. While this has been an exhausting day for all involved, tomorrow we will continue to fight back on last-minute appeals and efforts to block justice for the victims’ families.”

McKesson filed a complaint April 18 in Pulaski County Circuit Court seeking a restraining order and injunction to prevent the vecuronium it supplied from being used “for something other than a legitimate medical purpose.” The case has been assigned to Pulaski County Circuit Judge Alice Gray.

In another case, Baker cancelled an April 18 hearing in which the lawyers for Marcel Williams, who is scheduled to be executed April 24, intended to argue that because of his obesity, Arkansas' lethal injection protocol is not likely to kill him and could cause organ damage. Williams was convicted of the 1994 killing of Stacy Errickson.

Baker cited the Eighth Circuit's reversal of her earlier stay in her decision to cancel the hearing.

Both Bishop Anthony Taylor of Little Rock and Bishop Frank Dewane of Venice, the chair of the US bishops’ domestic justice and human development committee, have spoken out against the planned executions.

Arkansas' next executions are scheduled to be held the evening of April 20.