The US Supreme Court on Friday reinstated the death penalty for Dzhokhar Tsarnaev, who was convicted of killing three people and injuring hundreds of others with homemade bombs at the Boston Marathon in 2013.
A court of appeals had vacated Tsarnaev's death sentence but it was reimposed by the conservative-dominated Supreme Court in a 6-3 vote.
Federal executions resumed under former president Donald Trump but were halted after Democrat Joe Biden took office in January 2021.
Tsarnaev was 19 when he and his older brother Tamerlan planted two explosive devices near the finish line of the April 15, 2013, race, killing three people and injuring 264.
On the run, the two also killed a policeman. Tamerlan was killed in a gunfight with police.
Tsarnaev's 2015 conviction over the deadly bombing earned him sentences of both life imprisonment and capital punishment.
But his lawyers won an appeal of the death sentence on grounds that jurors had not sufficiently heard arguments about how Tsarnaev was deeply under his brother's influence in committing the crime.
The Justice Department under Trump rejected those arguments and appealed to the Supreme Court to reinstate the death penalty in the high-profile case.
Despite the moratorium on federal executions, Biden's attorney general Merrick Garland allowed the Justice Department's appeal to reinstate the original sentence to go ahead in the high court.
The six conservatives on the court agreed on Friday that the death sentence should be reinstated for the now 28-year-old Tsarnaev, who is incarcerated at Colorado's Supermax prison.
"Dzhokhar Tsarnaev committed heinous crimes," Justice Clarence Thomas said in the majority opinion.
"The Sixth Amendment nonetheless guaranteed him a fair trial before an impartial jury. He received one.
"The judgment of the United States Court of Appeals for the First Circuit is reversed."
