Should the Boston Marathon bomber’s trial have taken place in Boston as the city was still reeling from the traumatic 2013 attack?

That’s the crux of what’s being argued Thursday before the 1st U.S. Circuit Court of Appeals in Boston.

Lawyers for Dzhokhar Tsarnaev (juh-HAHR’ sar-NY’-ev) are seeking to have their client’s death sentenced overturned, arguing that he was subjected to a “fundamentally unfair proceeding.”

They say it was impossible to find a fair and impartial jury in Boston just two years removed from the April 15, 2013, attack, which killed three people and injured more than 260.

“This case should not have been tried in Boston,” the lawyers wrote in their legal brief. “Tsarnaev admitted heinous crimes, but even so —perhaps especially so — this trial demanded scrupulous adherence to the requirements of the Constitution and federal law. Again and again this trial fell short.”

Tsarnaev’s lawyers also point to two jurors who lied about what they knew about the attacks.

In one instance, a juror published two dozen Twitter posts in the aftermath of the bombings, including retweeting one after Tsarnaev’s arrest that read: “Congratulations to all of the law enforcement professionals who worked so hard and went through hell to bring in that piece of garbage.”

That juror, who would go one to become the foreperson, or chief spokesperson, had also tweeted about her family’s experience sheltering in place along with thousands of other greater Boston residents during the hunt for the bombers, Tsarnaev’s lawyers said.

Another juror posted on Facebook as he was going through the jury selection process. His friends encouraged him to “play the part” in order to get on the jury and make sure Tsarnaev was convicted.

Tsarnaev’s lawyers raised the social media comments as reasons to disqualify the two jurors before the trial started, but prosecutors downplayed them, saying they weren’t indicative of bias. Judge George O’Toole agreed and allowed them to remain on the case.

Tsarnaev’s lawyers also complain O’Toole wrongly excluded evidence suggesting Dzhokhar’s older brother, Tamerlan Tsarnaev, had committed a triple murder in Massachusetts in 2011, less than two years prior to the bombing.

During the 2015 trial, Dzhokhar Tsarnaev’s lawyers didn’t dispute that their client took part in the bombing, but they hoped to argue for a life sentence rather than death by drawing on those still-unsolved murders and other evidence.

They wanted to demonstrate that 26-year-old Tamerlan Tsarnaev was radicalized, violent and the mastermind behind the marathon attack while his younger brother had merely followed along.

Prosecutors maintain that Tsarnaev’s convictions and sentences were lawful.

They argue in their filings that despite the attack’s extensive publicity and widespread impact, it wasn’t impossible to convene an impartial jury in Boston, as Tsarnaev’s lawyers contend. Prosecutors also say O’Toole properly excluded evidence of the Waltham murders.

“Tsarnaev received a fair trial in Boston, and the district court did not abuse its discretion by refusing to move the trial elsewhere,” they wrote. “The jurors who tried and sentenced Tsarnaev were unbiased.”

Robert Bloom, a Boston College law professor, says Tsarnaev’s lawyers have a compelling case to make.

The death penalty trial of 1995 Oklahoma City bomber Timothy McVeigh was moved to Denver over similar concerns about impartiality, he noted.

“The Boston Marathon is in the very DNA of the city. It’s like Fenway Park and Paul Revere’s house,” Bloom said. “And the bombing affected everyone. Everyone had to shelter in place. Everyone had those Boston Strong shirts.”

Tamerlan Tsarnaev was killed in a gun battle with police days after the brothers detonated two pressure cooker bombs near the marathon finish line.

Dzhokhar Tsarnaev was convicted of all 30 charges against him, including conspiracy and use of a weapon of mass destruction.

Each side has been allotted an hour to make its case Thursday, and the judges are expected to hand down a decision at a later date.

If overturned, prosecutors can seek a new death penalty trial or allow Tsarnaev to accept the life sentence his lawyers originally sought.

If the sentence is upheld, his lawyers have other options for appeal, including to the U.S. Supreme Court.

Tsarnaev isn’t expected to be present for Thursday’s hearing. The now-26-year-old is currently in custody in a supermax prison in Colorado.

(AP)