( CNN ) -- A federal court has granted a stay of execution for white supremacist serial killer Joseph Paul Franklin , hours before he was scheduled to die by lethal injection in Missouri . Franklin is on death row for the 1977 murder of Gerald Gordon outside a synagogue in St. Louis . He 's been blamed for a total of 22 killings between 1977 and 1980 in a bid to start a race war . He is challenging Missouri 's decision to use the drug pentobarbital in its lethal injection protocol , arguing it would violate the Constitution 's ban on cruel and unusual punishment . U.S. District Judge Nanette Laughrey granted a stay on Tuesday , finding Franklin 's lawyers showed the use of pentobarbital carried `` a high risk of contamination and prolonged , unnecessary pain beyond that which is required to achieve death . '' An intimate discussion with a serial killer . `` Given the irreversible nature of the death penalty and plaintiffs ' medical evidence and allegations , a stay is necessary to ensure that the defendants ' last act against Franklin is not permanent , irremediable cruel and unusual punishment in violation of the Eighth Amendment , '' Laughrey wrote . Another federal judge granted a second stay Tuesday , based on a separate defense petition contesting Franklin 's competency . `` The Court concludes that a stay of execution is required to permit a meaningful review , '' U.S. District Judge Carol Jackson wrote . The state is appealing both stays to the 8th U.S . Circuit Court of Appeals . Defense attorney Jennifer Herndon said that she expects that court will rule within the next day . The execution warrant window is 24 hours , meaning that if the court rules against the stays , Franklin could still be put to death on Wednesday . `` We 're hoping the stays stay in place , '' Herndon said , adding that she would be surprised if both were vacated . Franklin had been scheduled to be put to death shortly after 12 a.m. Wednesday ( 1 a.m . ET ) at the state prison in Bonne Terre , Missouri , about 60 miles south of St. Louis . But Missouri and other states that conduct executions have had to scramble for new drugs after European-based manufacturers banned American prisons from using their drugs in executions . Missouri had planned to use propofol , the surgical anaesthetic made infamous by the death of pop star Michael Jackson . But Gov . Jay Nixon reversed that decision after being warned the European Union -- whose members forbid capital punishment -- might halt shipments of the drug , leading to shortages for medical purposes . In October , the state announced it would use pentobarbital , which would be provided by an unnamed compounding pharmacy . Franklin 's lawyers argued that would raise the risk of contamination and a painful death . Nixon denied clemency for Franklin on Monday , arguing Franklin had committed `` merciless acts of violence , fueled by hate . '' In addition to the killings , Franklin admitted to the attempted assassinations of Hustler magazine publisher Larry Flynt in 1978 and civil rights leader Vernon Jordan in 1980 . Flynt , who was paralyzed by Franklin 's bullet , has called for clemency for Franklin , saying `` the government has no business at all being in the business of killing people . '' States scramble for lethal injection drugs . CNN 's Dana Ford contributed to this report .
NEW : Another judge grants a second stay on a separate defense appeal . NEW : ` ` We 're hoping the stays stay in place , '' says defense attorney . Joseph Paul Franklin had been set to die shortly after midnight Tuesday . He was convicted of murdering his wife and two children in their home in 1993.