Missouri is set to execute its sixth inmate in as many months this week.
But lawyers for the most recent death row inmate, William Rousan, attempted to stop his death on Tuesday over ethical concerns regarding the state's secret lethal injection drugs, according to Reuters. The case moved onto the U.S. Supreme Court after the Eighth U.S. Circuit Court of Appeals on Monday rejected Rousan's appeal, according to the report.
Rousan, who was found guilty in the murder of a 62-year-old and her 67-year-old husband in 1993, is scheduled for execution Wednesday at 12:01 a.m. Central Standard Time.
The attempted motion comes one day after the Oklahoma Supreme Court halted two similar executions in that state for inmates Clayton Lockett and Charles Warner. The court ruled the individuals have the right to challenge the secret drugs the state would use in their executions. Previously, an Oklahoma appeals court in March delayed the executions of Lockett and Warner until the end of this month.
Lockett was found guilty of the 1999 murder of a 19-year-old woman who was raped, shot, and buried alive. Warner received a death penalty sentence for raping and killing his girlfriend's 11-month-old baby daughter in 1997.
Officials in Oklahoma and other states that use the death penalty have scrambled recently to find new suppliers of lethal injection drugs after several pharmaceutical companies stopped carrying the medication because of ethical concerns.