Missouri carried out the execution of Joseph Paul Franklin a little after 6 a.m. He was put to death after courts overturned Tuesday's stays of execution.
Yesterday, two federal judges issued stays of execution.
The judges took issue with how the state was getting its lethal injection drug from a secret source not regulated by the Food and Drug Administration, and questioned whether the inmate was mentally competent to be executed.
The state of Missouri, led by Attorney General Chris Koster, appealed quickly.
Missouri Governor Jay Nixon has responded to the recent controversy surrounding the execution drug propofol by halting the execution of a Missouri inmate, and asking that a different form of lethal injection be used.
Attorney General Chris Koster says Missouri may have to resort to using the gas chamber to carry out death sentences as an "unintended consequence" of the state Supreme Court's refusal to set execution dates.
Executions have been on hold in Missouri since the state Supreme Court has declined to set execution dates. The court says execution dates would be "premature" until a federal legal challenge is resolved regarding the use of the drug propofol as Missouri's new execution method.