The US supreme court on Friday reinstated the convicted Boston Marathon bomber Dzhokhar Tsarnaev’s death sentence for his role in the 2013 attack that killed three people and wounded more than 260 others, ruling in favor of the federal government. In a 6-3 decision, the justices sided with the justice department’s challenge to a 2020 lower court ruling that had upheld Tsarnaev’s conviction but overturned his death sentence. The supreme court faulted the Boston-based first US circuit court of appeals on its findings both that Tsarnaev’s right to a fair trial under the US constitution’s sixth amendment was violated and that the trial judge wrongly excluded certain evidence about a separate crime. “Dzhokhar Tsarnaev committed heinous crimes. The sixth amendment nonetheless guaranteed him a fair trial before an impartial jury. He received one,” the conservative justice Clarence Thomas wrote for the court. The court’s six conservative justices were in the majority, with its three liberals dissenting. Joe Biden as a candidate promised to work to pass legislation in Congress to eliminate the death penalty at the federal level and set incentives for states to do as well, instead endorsing life sentences without probation or parole. But his administration last year opted to proceed with an appeal initially launched by the justice department under his predecessor Donald Trump to defend Tsarnaev’s death sentence. In a dissenting opinion, liberal justice Stephen Breyer agreed with the first circuit that evidence about the separate crime, a 2011 triple murder in Waltham, Massachusetts, linked to Tsarnaev’s older brother Tamerlan, was improperly excluded. Lawyers for Tsarnaev, who is 28 now and was 19 at the time of the attack, have argued that Tsarnaev played a secondary role in the marathon bombing to his brother Tamerlan, who they called “an authority figure” with “violent Islamic extremist beliefs”. As such, the evidence about another crime Tamerlan allegedly committed would be relevant, they argued. “This evidence may have led some jurors to conclude that Tamerlan’s influence was so pervasive that Dzhokhar did not deserve to die for any of the actions he took in connection with the bombings, even those taken outside of Tamerlan’s presence,” Breyer wrote. “And it would have taken only one juror’s change of mind to have produced a sentence other than death, even if a severe one,” added Breyer, who in the past has questioned the constitutionality of the death penalty. The primary source of the evidence about the other murders, a man named Ibragim Todashev, was killed by an FBI agent in 2013 when he attacked officers during an interview. The supreme court also found that US district judge George O’Toole, who presided over the trial, did not violate Tsarnaev’s right to a trial in front of an impartial jury by failing to properly screen jurors for potential bias following pervasive news coverage of the bombings. The Tsarnaev brothers detonated two homemade pressure-cooker bombs at the marathon’s finish line on 15 April 2013, and days later killed a police officer. Tamerlan Tsarnaev died after the gunfight with police. Jurors convicted Dzhokhar Tsarnaev in 2015 on all 30 counts he faced and determined he deserved execution for a bomb he planted that killed Martin Richard, eight, and Chinese exchange student Lingzi Lu, 23. Restaurant manager Krystle Campbell, 29, was killed by the second bomb. Marc Fucarile, who lost his right leg in the second blast, said the supreme court “did the right thing”. No federal inmates were executed for 17 years before Donald Trump oversaw 13 executions in the last six months of his term. Biden’s attorney general, Merrick Garland, last July imposed a moratorium on federal executions while the justice department reviews the death penalty. The White House press secretary, Jen Psaki, said in March 2021 that Biden continues to have “grave concerns about whether capital punishment, as currently implemented, is consistent with the values that are fundamental to our sense of justice and fairness”.