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.
On Tuesday, the Missouri Department of Corrections announced that it had selected a new drug for upcoming executions: pentobarbital.
The change comes following criticism of the questionable methods Missouri had obtained the drug it had previously planned to use, as well as concern that its use could harm hospitals throughout the U.S. The state had planned to use a common anesthetic named propofol, which has never been used to carry out an execution.