The Supreme Court reinstated the death penalty on Friday for convicted Boston Marathon bomber Dzhokhar Tsarnaev.

The 6-3 vote comes after a federal appeals court tossed the sentence in July 2020, ruling that a trial judge improperly excluded evidence that may have shown Dzhokhar was influenced by his late older brother, Tamerlan.

The First US Circuit Court of Appeals in Boston also cited potential juror bias over exposure to news coverage of the pressure cooker bombing that killed three people and wounded more than 260 others near the race’s finish line in 2013 while vacating Tsarnaev’s death sentence nearly two years ago.

“Dzhokhar Tsarnaev committed heinous crimes,” Justice Clarence Thomas wrote for the majority, comprising the court’s six conservative members. “The Sixth Amendment nonetheless guaranteed him a fair trial before an impartial jury. He received one.”

Justice Stephen Breyer, who dissented along with Justices Sonia Sotomayor and Elena Kagan, said he believed the appellate court “acted lawfully” while noting “particular judicial care” is necessary surrounding death penalty cases.

“This Court now reverses the Court of Appeals,” Breyer wrote. “In my view, the Court of Appeals acted lawfully in holding that the District Court should have allowed Dzhokhar to introduce this evidence.”

Tsarnaev had argued during the sentencing phase of his trial that he shouldn’t be put to death because Tamerlan “took the leading role” in the bombing and brought his brother into his plan.

“Dzhokhar argued that Tamerlan was a highly violent man, that Tamerlan radicalized him, and that Dzhokhar participated in the bombings because of Tamerlan’s violent influence and leadership,” Breyer wrote.

To back up his claims, Dzhokhar, 28, tried to introduce evidence that Tamerlan previously killed three people in an unrelated triple murder in Waltham, Massachusetts, in 2011.

Breyer also called on his counterparts to take reconsider capital punishment altogether.

“I have written elsewhere about the problems inherent in a system that allows for the imposition of the death penalty,” Breyer wrote in his dissent. “This case provides just one more example of some of those problems.”

Days after the bombing on April 15, 2013, Tamerlan, 26, died during a police shootout and was run over by his brother as he fled. Hours later, Dzhokhar was captured while hiding in a boat in the Boston suburb of Watertown.

Ginger Anders, Dzhokhar Tsarnaev’s lead Supreme Court attorney, told the justices in October the evidence bolstered the theory that “Dzhokhar radicalized because of Tamerlan.” She claimed Tamerlan indoctrinated his younger brother.

But Thomas and five other justices ruled Friday that the trial judge’s decision to exclude the evidence connected to the Waltam triple killing was reasonable.

“Dzhokar sought to divert the sentencing jury’s attention to a triple homicide that Tamerlan allegedly committed years prior, though there was no allegation that Dzokhar had any role in that crime,” Thomas wrote. “Nor was there any way to confirm or verify the relevant facts, since all of the parties involved were dead.”

Both Tamerlan and a man who implicated him, Ibragim Todashev, had died before the start of the Dzokhar’s trial.

Todashev, 27, told authorities after the marathon bombing that Tamerlan recruited him to rob three men before the elder Tsarnaev slashed their throats.

Todashev died in May 2013 when an FBI agent shot the Chechen man in Orlando while he was being questioned by authorities about his friendship with Tamerlan.

It’s unclear when Tsarnaev may be put to death since the Justice Department announced a moratorium on federal executions in July.

With Post wires