Marvin Bieghler, 58, was pronounced dead at 2:17 a.m. EST after a lethal injection, state Department of Correction spokeswoman Java Ahmed said. Like a man on Florida's death row, he had challenged the method of execution.
Bieghler's final words were "Let's get it over with," she said.
The U.S. Supreme Court announced a 6-3 decision to overturn a federal appeals court ruling late Thursday, causing the execution to be delayed about 30 minutes.
The appeals court decision had granted Bieghler a stay of execution to challenge the legality of lethal injection, even though the high court rejected a similar appeal just hours earlier.
Gov. Mitch Daniels turned down a clemency request Thursday.
Bieghler, like Florida inmate Clarence Hill, challenged lethal injection as unconstitutional. Hill contends the three chemicals used in Florida's method of execution — the same as those used in Indiana — cause pain, making his execution cruel and unusual punishment.
The Supreme Court said Wednesday it would hear arguments in Hill's case, with the justices to decide whether a federal appeals court was wrong to prevent Hill from challenging the lethal injection method.
Bieghler's case differed from Hill's because he was allowed to contest the Indiana execution method and lost.
The Supreme Court has never found a specific form of execution to be cruel and unusual, and the Florida case does not give the court that opportunity. The justices could, however, spell out what options are available to inmates with last-minute challenges to the way they will be put to death.
Bieghler's attorney, Brent Westerfeld, had told justices in a motion Thursday that a "grave injustice may arise" if Bieghler was executed while Hill's case is pending because there is a chance that Hill will win the right to pursue his claim against lethal injection and eventually win.
The state attorney general's office argued that Bieghler's appeal was a delay tactic and that Indiana's chemical injection method of execution, used since 1996, was constitutional.
The state argued that the Constitution does not guarantee a pain-free execution.
"Indeed, electrocution is a constitutionally permissible form of execution which is undoubtedly more painful than lethal injection," the brief said.
Justice John Paul Stevens, Ruth Bader Ginsburg and Stephen Breyer voted to grant the stay, court spokesman Ed Turner said.
About 25 people protested Thursday night against the death penalty outside the prison.
On Monday, the Indiana Parole Board voted unanimously against recommending clemency for Bieghler, and Daniels issued a brief statement Thursday saying he had reviewed Bieghler's petition and rejected it.
Bieghler was convicted in the deaths of Tommy Miller, 20, and Kimberly Jane Miller, 19, whose bodies were found Dec. 11, 1981, in their mobile home near the Howard County town of Russiaville, about 10 miles west of Kokomo.
Tommy Miller had been shot six times and his wife, who was four weeks pregnant, was shot three times. Bieghler told the parole board last week that he did not kill the couple and wanted Daniels to commute his death sentence to time served.