Supreme Court hears arguments on reinstating the death penalty for Boston Marathon bomber Dzhokhar Tsarnaev

Dzhokhar TsarnaevAssociated Press

The US Supreme Court heard arguments Wednesday over reinstating the death sentence for Boston Marathon bomber Dzhokhar Tsarnaev, focusing sharply on whether he was under the sway of his domineering, violent older brother, Tamerlan, when the pair exploded bombs near the finish line in 2013.

The justices’ questions centered around whether jurors in the 2015 trial who recommended the younger Tsarnaev be sentenced to death would have instead voted to spare his life if they were told of his brother’s alleged involvement in an unrelated triple murder in Waltham.

The trial judge had ruled that the defense could not introduce evidence related to the Waltham slayings. That decision was one reason cited by a federal appeals court when it overturned Tsarnaev’s death sentence last year, ruling he did not receive a fair trial.

“The defense’s entire argument was that Dzhokhar was less culpable because Tamerlan indoctrinated him and then led the bombings,” said Tsarnaev’s lawyer Ginger Anders.

Anders said there was evidence that Tsarnaev, now 28, learned that his brother, who held extremist Islamic beliefs, “had irrevocably committed himself to violent jihad” by killing three drug dealers, including a close friend, on Sept. 11, 2011. That would have made Dzhokhar Tsarnaev feel intense pressure to accept that extremist violence was justified, she said.

Excluding that evidence allowed prosecutors to mislead jurors by arguing that Tamerlan Tsarnaev “was merely bossy” and that the brothers were “equal partners” in the bombings because Tamerlan had not succeeded in jihad until Dzhokhar joined him, she argued. Tamerlan Tsarnaev was killed in a shootout with police, and Dzhokhar Tsarnaev was convicted in the bombings that killed three people and wounded hundreds more.

The hearing came a year after the appeals court ruled Tsarnaev did not receive a fair trial because of a failure to adequately screen jurors for bias, and for the exclusion of evidence about the Waltham murders during the sentencing phase of the case.

It upheld Tsarnaev’s convictions but ordered the government to hold a new death penalty trial, a highly emotional prospect for victims of the attack, or let him serve a life sentence.

Deputy Solicitor General Eric J. Feigin, who argued for the government, said evidence related to the triple murders was unreliable and that exploring the allegations would have created a “mini trial.” No one has been charged with the slayings and a man who implicated Tamerlan Tsarnaev was killed in a confrontation with the FBI.

“Even if the court of appeals had identified a misstep in one of the hundreds of judgment calls that this complex trial required, any error here was harmless,” Feigin said. “The experienced district judge empaneled an impartial jury which heard overwhelming evidence about [Tsarnaev’s] own actions and motivations and rendered a sound judgment against a motivated terrorist who willingly maimed and murdered innocents, including an eight-year-old boy, in furtherance of jihad.”

There is no timetable for the court’s ruling.

Dzhokhar Tsarnaev was sentenced to death for placing a bomb in front of the Forum restaurant on Boylston Street that killed 8-year-old Martin Richard and Lingzi Lu, a 23-year-old Boston University graduate student from China. Tamerlan Tsarnaev placed the bomb that killed Krystle Campbell, 29, of Arlington.

The brothers also killed MIT police officer Sean Collier while they were on the run after the bombings.

The month after the bombings, Tamerlan Tsarnaev was implicated in the Waltham slayings by a friend, Ibragim Todashev, who told the FBI that they only planned to rob the men, who sold marijuana, but Tsarnaev killed them because he didn’t want any witnesses, according to court filings. Shortly after making the statements, Todashev was fatally shot by an FBI agent whom he allegedly attacked, according to officials.

Dzhokhar Tsarnaev admitted to his crimes, but his lawyers argued against the death penalty, saying he was less responsible because of his brother’s influence.

On Wednesday, Justice Elena Kagan said, “The entire point of the defendant’s mitigation case was that he was dominated by, unduly influenced by his older brother, and that would have gone exactly to that point.”

She questioned the trial judge’s decision to exclude evidence about the Waltham slayings while allowing jurors to hear other evidence about Tamerlan Tsarnaev that included him “poking somebody in the chest,” shouting at people in a mosque, and assaulting a former student.

Feigin said the bombings and Waltham murders were “extremely different” crimes, one an apparent robbery of three drug dealers and the other “a sophisticated public spectacle that required reading directions in a jihadist magazine on how to build and construct bombs and deliberately placing them at the finish line of the Boston Marathon.”

The evidence related to the murders was “very unreliable” because Todashev, the alleged accomplice in the Waltham crime, “had every incentive to pin this entire thing on Tamerlan,” who was already dead, Feigin said.

“This investigation had hit the end of the road,” Feigin said. “There’s no way to figure out what happened.”

Justice Stephen Breyer said Dzhokhar Tsarnaev had admitted he was guilty of the bombings, and his only defense was “don’t give me the death penalty because it’s my brother who was the moving force.”

He noted that the government found Todashev’s claims about the murders reliable enough to establish probable cause in support of a warrant to search a car, and suggested the same evidence should have been allowed before jurors weighing the death penalty.

At one point, Justice Brett Kavanaugh asked Anders if the defense’s theory was that Tamerlan Tsarnaev was a “worse person” than his brother because of his participation in the earlier triple murder.

“Is that the theory?” Kavanaugh asked. “Or explain to me the theory, because that’s not registering completely with me.”

Anders said the theory was that Tamerlan Tsarnaev indoctrinated and radicalized his brother and “was more likely to have led the bombings.”

Justice Samuel Alito said evidence related to the Waltham murders would be “inadmissible many times over in a regular trial” and questioned whether the rules in the mitigation phase of a death penalty case meant “anything goes.”

Justice Amy Coney Barrett grilled Feigin about “the government’s end game,” noting that the government has declared a moratorium on executions yet is defending Tsarnaev’s death sentence.

“And if you win, presumably, that means that he is relegated to living under the threat of a death sentence that the government doesn’t plan to carry out,” she said. “So I’m having trouble following the point.”

And, Justice Sonia Sotomayor grilled Feigin about a defendant’s constitutional right to present mitigating evidence in capital cases and she said the question of Todashev’s reliability was irrelevant.

“It doesn’t really matter who took the lead in the [Waltham] killing or even if the brother participated,” Sotomayor said. “The only issue would have been, what did [the] defendant think? And so I’m not sure whether the relevancy issue the district court ruled on made any sense to me.”

Feigin pointed to legal filings indicating that Dzhokhar Tsarnaev hadn’t asserted he knew about the Waltham murders.

“We acknowledged it would be a different story if he had,” Feigin said.

But Anders disputed that, telling justices there was evidence that Dzhokhar Tsarnaev told a friend that his brother committed the Waltham murders “as an act of jihad.”