The U.S. Supreme Court on Wednesday evening granted a stay of execution to Missouri inmate Russell Bucklew pending the outcome of another appeal to the U.S. Court of Appeals for the Eighth Circuit. That circuit had already thrown out an execution stay granted by a panel of its own court.

Although the high court halted the execution, it was not immediately clear whether it would be cancelled indefinitely or how quickly the Eighth Circuit might act again. Missouri has a 24-hour window in which a scheduled execution is to take place before state officials must reschedule it.