Two Arkansas inmates were granted stays of executions on Monday in an ongoing case concerning their lack of access to independent mental health experts, halting the state’s plan to begin carrying out executions.

A preliminary injunction was dissolved late Monday by a federal appeals court for a lawsuit arguing that the pace of the executions and the use of the drug midazolam were unconstitutional. The state had scheduled these executions in quick succession because its supply of midazolam, one of three drugs used in its procedure, is set to expire at the end of April.

In a separate case, an Arkansas judge issued a temporary restraining order on Friday after two pharmaceutical companies argued that the state had obtained some of its lethal injection drugs under false pretenses.

An Unprecedented Schedule

Since 1976, the year the death penalty was reinstated nationally, multiple executions in one state on a single day have occurred only 10 times. The last time was 17 years ago in Texas. Arkansas conducted double executions nearly a year before that.

Executions by day of 20 states with the most executions Red represents multiple executions in a day

Arkansas originally planned to carry out eight executions in 10 days. No state has tried to execute so many people in such a short period. Virginia is the only other state with an execution scheduled this month.

Date Inmate Status April 17 Bruce Ward Execution stayed April 17 Don Davis Execution stayed April 20 Stacey Johnson Blocked by court order April 20 Ledell Lee Blocked by court order April 24 Marcel Williams Blocked by court order April 24 Jack Jones Blocked by court order April 27 Kenneth Williams Blocked by court order April 27 Jason McGehee Execution stayed

All the executions in Arkansas are currently blocked by a restraining order from the state. Three of the inmates were granted stays of execution outside of that decision.

The last attempt to carry out two executions in a day resulted in chaos. In April 2014 in Oklahoma, the inmate Clayton Lockett was awake and writhed in pain during the administration of the lethal drugs, even though earlier a doctor had announced that Mr. Lockett was unconscious. The state canceled a second execution originally scheduled on that day.

The Oklahoma Department of Public Safety later recommended that executions be at least seven days apart, citing the botched execution and saying it was partly a result of “extra stress” from having two executions planned on the same day.

The Missouri Supreme Court adopted a rule in 2016 that limited executions to one per month.

“Corrections officers are not hired executioners,” states the Arkansas inmates’ federal complaint. It argues that the emotional toll of the job and the rushed schedule greatly increase the risks of causing unnecessary pain and suffering for the inmates, a violation of the Eighth Amendment.

A letter to the Arkansas governor, Asa Hutchinson, from dozens of former corrections officials and administrators also expressed concerns that the schedule “will impose extraordinary and unnecessary stress and trauma on the staff responsible with carrying out the executions.”

“Multiple executions create rushed circumstance. Rushed circumstances risk error,” said Robert Dunham, executive director of the Death Penalty Information Center, a nonprofit research group on capital punishment.

Mr. Dunham argued further that the only reason for such a compressed schedule was the expiration date of the injection drugs, calling it “an arbitrary kill-by date.”

The Drug in Question: Midazolam

After other medications became unavailable, Arkansas turned to midazolam, a common sedative that has become a drug of choice for executions in several states.

The complaint filed by the Arkansas inmates argues that the use of midazolam is unconstitutional because the lack of anesthetic potency of the drug is all but certain to cause “excruciating suffering.”

A number of pharmaceutical companies have restricted the use of their drugs in executions, contending that their products are made to promote human health, not for killing. Roche, a developer of midazolam, publicly stated in 2015 that it “did not supply midazolam for death penalty use and would not knowingly provide any of our medicines for this purpose.”

Since midazolam’s first use in an execution in October 2013, there have been at least four botched executions involving the drug. After the execution team administered midazolam and confirmed that the inmates were sedated, the individuals awoke, struggled or convulsed while being injected with the subsequent lethal drugs.

States with lethal injection protocols Have not used midazolam Have used or plan to use midazolam Wash. Mont. Ore. N.H. Idaho S.D. Wyo. Pa. Neb. Nev. Ohio Ind. Utah Colo. Va. Calif. Kan. Mo. Ky. N.C. Tenn. Okla. Ariz. Ark. S.C. Ala. Ga. Miss. La. Tex. Fla. Ohio Va. Ky. Ariz. Okla. Ark. Ala. Fla.