WASHINGTON — The Supreme Court said on Monday that it would review an appeals court’s decision that threw out the death sentence of Dzhokhar Tsarnaev, who was convicted of helping carry out the 2013 Boston Marathon bombings.
Last year, a three-judge panel of the U.S. Court of Appeals for the First Circuit, in Boston, upheld Mr. Tsarnaev’s convictions on 27 counts. But the appeals court ruled that his death sentence should be overturned because the trial judge had not questioned jurors closely enough about their exposure to pretrial publicity and had excluded evidence concerning Tamerlan Tsarnaev, his older brother and accomplice.
“A core promise of our criminal justice system is that even the very worst among us deserves to be fairly tried and lawfully punished,” Judge O. Rogeriee Thompson wrote for the panel.
“Just to be crystal clear,” Judge Thompson wrote, “Dzhokhar will remain confined to prison for the rest of his life, with the only question remaining being whether the government will end his life by executing him.”
After the appeals court ruling, lawyers for the federal government during the Trump administration urged the Supreme Court to hear the case.
The case presents President Biden with an early test of his stated opposition to capital punishment. Were the administration to decide not to pursue the death penalty against Mr. Tsarnaev, the Supreme Court case would become moot.
Jen Psaki, the White House press secretary, answered generally when asked about how Mr. Biden would approach the case.
“He has grave concerns about whether capital punishment as currently implemented is consistent with the values that are fundamental to our sense of justice and fairness,” Ms. Psaki said at a press briefing on Monday. “He has also expressed his horror at the events of that day and Tsarnaev’s actions.”
A Justice Department spokeswoman declined to comment.
The bombings, near the finish line of the marathon, killed three people and injured 260, many of them grievously. Seventeen people lost limbs. A law enforcement officer was killed as the brothers fled a few days later. Tamerlan Tsarnaev died in a shootout with the police.
Judge Thompson wrote that the trial judge should not have excluded evidence that Tamerlan Tsarnaev had been involved in a triple murder in 2011, which could have bolstered an argument from defense lawyers that he had dominated and intimidated his younger brother.
The Trump administration had called on the court to hear the case even though it did not satisfy some of the usual criteria for review.
“Although the court of appeals’ errors are largely case-specific, the context of this case makes them exceptionally significant,” the government’s brief said.
The appeals court’s ruling allowed prosecutors to try again to obtain the death penalty at a new sentencing hearing with jurors who are subjected to closer questioning and provided with more information about Tamerlan Tsarnaev. The government’s brief said that would subject jurors and witnesses to needless burdens.
In particular, the brief said, “the victims will have to once again take the stand to describe the horrors that respondent inflicted on them.”
Nancy Gertner, a retired federal judge who now teaches at Harvard Law School, said the Biden administration should consider whether it wants to pursue the appeal.
“Given that Mr. Tsarnaev will never leave prison,” she said in a statement, “the government should consider whether continuing to pursue a death sentence for him is unnecessarily traumatizing for the victims’ families and the city of Boston.”
Until July, there had been no federal executions in 17 years. In the six months that followed, the Trump administration executed 13 inmates, more than three times as many as the federal government had put to death in the previous six decades.
Mr. Tsarnaev is not the only inmate on federal death row who has had his death sentence overturned. The day before Mr. Biden assumed office, a three-judge panel of the U.S. Court of Appeals for the 10th Circuit, in Denver, vacated the death sentence of Kenneth Barrett, who had been convicted of killing a state trooper, saying his lawyers had not represented him effectively.
The government has not filed an appeal to the Supreme Court in Mr. Barrett’s case, and it is unclear whether it will do so.
Robert Dunham, the executive director of the Death Penalty Information Center, said the Supreme Court’s decision to hear the case from Boston was driven by its notoriety. “Tsarnaev is an extraordinary case by any measure,” he said, adding that the case will help force the new administration to clarify its stance on capital punishment.
“At some point, they’ll have to make a decision on what their policy is,” Mr. Dunham said. “Cases like this will tell us how serious the president’s pledge was to work to end the death penalty.”
Hailey Fuchs and Katie Benner contributed reporting.