Dzhokhar Tsarnaev is no Walter McMillian, the central figure in Bryan Stevenson’s landmark book (now a movie) “Just Mercy.” McMillian spent six years on Alabama’s Death Row for a murder he did not commit, while Tsarnaev is, in plain English, a cold-blooded killer.

On Patriots’ Day, April 15, 2013, Tamerlan and Dzhokhar Tsarnaev set off homemade shrapnel bombs just short of the Boston Marathon finish line. Hundreds of spectators were seriously injured, and three—Krystle Campbell, Lingzi Lu, and Martin Richard— were killed. (The brothers later killed a policeman named Sean Collier.)

During the manhunt that followed Tamerlan died in a police shootout when Dzhokhar, trying to escape, ran over him. At that point, the words “shelter in place” became part of the Greater Boston vocabulary, and the police found Dzhokhar the next day, hiding in a boat in a Watertown back yard.

There was never any question about Dzhokhar’s guilt. At his 2015 federal court trial in Boston under the Federal Death Penalty Act, he admitted (through his lawyer) that he had committed the crimes. The focus of his defense was almost entirely on the penalty phase of the case. After hearing weeks of testimony and viewing hundreds of exhibits, the jury convicted Tsarnaev and unanimously recommended the death sentence, which trial judge George O’Toole then imposed.

The death penalty in America is as old as the country itself. George Washington signed the Crimes Act of 1790, and presidents of both parties, including Bill Clinton, George W. Bush, and Barack Obama have re-affirmed it one way or another. In addition to the twenty-eight states that still have the death penalty (New Hampshire abolished it in 2019), federal law, under which Tsarnaev was charged, allows the death penalty for treason, espionage, and certain forms of murder.

Between 2003 and last month, however, no one convicted of a capital crime under federal law had been executed. Then, on July 14, 16, and 17, 2020, three murderers—each convicted more than twenty years ago—were executed. Meanwhile, Tsarnaev appealed his death sentence to the First Circuit Court of Appeals, which issued its opinion on July 30, 2020. The court did not decide whether Tsarnaev deserves to die, but it did answer another question, which was whether Judge O’Toole conducted the trial, including voir dire (empanelment) of prospective jurors, with the requisite degree of skill and fairness.

Early in its thesis-long 182-page opinion the court tells us what is at stake: “A core promise of our criminal-justice system is that even the very worst among us deserves to be fairly tried and lawfully punished.” What then follows is a detailed recitation of what went wrong and why Judge O’Toole’s handling of the case did not live up to that standard. The First Circuit vacated the death sentence and sent the case back for a new penalty trial.

According to the court, the judge should have probed more deeply into what prospective jurors knew about the case, their exposure to media (both social and traditional), and their attitudes about the death penalty—all of which defense counsel repeatedly asked him to do. Under the so-called Patriarca standard (named after a case involving the head of the Mafia in New England), the judge should have delved into the specifics of what the jurors had read or heard about the case and not just inquired in general terms about their impartiality. “A judge cannot delegate to potential jurors the work of judging their own impartiality.”

Another serious mistake was refusing to allow the jury to hear potentially mitigating evidence about older brother Tamerlan’s prior crimes. Dzhokar, who had no criminal past, claimed that his brother had led him on and radicalized him, as he had earlier done to others, which would bear on the brothers’ relative culpability. In the court’s view, “The omitted evidence might have tipped at least one juror’s decisional scale away from death.”

Whether the federal government will try once again to execute Tsarnaev, or forego another death penalty trial and leave him confined in prison for the rest of his life, remains to be seen. Despite my personal opposition to the death penalty, my purpose is not to express an opinion on whether such a trial should take place or whether Tsarnaev deserves to die. It is simply to point out that this case goes beyond the fate of this one man. By reminding us that “even the worst among us,” not just the Walter McMillians, is entitled to an impartial jury, and insisting on scrupulous adherence to that core promise that we have made to ourselves, the First Circuit has reinforced a standard of fairness that strengthens our legal system.