Challenges

Judge Tanya Chutkan of the US district court in Washington had on Monday ordered the US justice department to delay four executions scheduled for July and August. She cited continuing legal challenges to the lethal injection method used in executions.

Her order, later backed by a US appeals court, was issued less than seven hours before the execution of Lee was due to take place in Indiana.

“The plaintiffs in this case have not made the showing required to justify last-minute intervention by a Federal Court. Last-minute stays like that issued this morning should be the extreme exception, not the norm,” the Supreme Court said.

Constitutionality

The vote was 5-4, with one judge, Stephen Breyer, expressing doubts about the constitutionality of the death penalty.

"The resumption of federal executions promises to provide examples that illustrate the difficulties of administering the death penalty consistent with the Constitution," he said.

Lee would be the first federal inmate to be executed in the United States since 2003 and the first since US President Donald Trump announced plans to resume federal executions.