The Supreme Court in the US state of Arkansas has stayed the execution of Stacey Johnson, one of two inmates due to die on Thursday, and returned his case to the trial court for reconsideration of potential DNA evidence.
It is another obstacle as Arkansas tries to execute eight prisoners in 11 days.
Minutes later a state circuit judge granted a temporary restraining order barring the state from using one of three drugs employed in its execution protocol.
The order was requested by McKesson Medical-Surgical, which has accused the state of obtaining the drug, pancuronium bromide, under false pretenses.
McKesson said it would not have sold the drug to the Arkansas prison system had it known it would be used in executions. The company is demanding that the drug either be returned or impounded.
Arkansas officials have said they are unable to obtain the necessary drug from any other source, and have acknowledged in court papers that should McKesson prevail, all pending executions would be effectively blocked.
State Attorney General Leslie Rutledge, a Republican, said that she would appeal the restraining order to the state Supreme Court.
An appeal of Johnson's stay of execution was undecided.
Pending before the US Supreme Court is an appeal by all eight inmates, who contend the compressed execution schedule increased the likelihood of a botched execution and that one of the three drugs, midazolam, has been proven ineffective in rendering unconsciousness prior to administration of the two lethal agents.
The executions set for Thursday would have been the first in Arkansas in a dozen years, and the eight together would have been the most for any state in as a short a period since the U.S. death penalty was reinstated in 1976.
Governor Asa Hutchinson set the unprecedented schedule due to one of the drugs in the state's lethal injection mix expiring at the end of the month. He said on Wednesday he was "both surprised and disappointed" by the delays.
Johnson was convicted of the 1993 murder and sexual assault of Carol Heath. Prosecutors said he beat, strangled and slit Heath's throat while her 6-year-old daughter watched.
Johnson's lawyers said experts have proven the child's testimony was unreliable. They also said the execution should be put on hold to allow for newer types of DNA testing that were previously unavailable.
"Today's techniques are much more sophisticated and precise than the methods used before trial," lawyer Jeff Rosenzweig said after the ruling. "We think it will go a long way toward exonerating him."
Lee was convicted of beating Debra Reese to death with a crowbar in 1993.