Reginald Reddick is serving life in prison in Louisiana for second-degree murder, even though two jurors at his 1997 trial found him not guilty. Almost anywhere else in the country, he would have been acquitted: even one juror would have been enough to change the outcome.

This week, the Louisiana supreme court will hear oral arguments in Reddick’s case, in which he argues that he is entitled to a new trial. The court’s decision could affect more than 1,000 people who, like Reddick, are serving time for crimes that some of their jurors did not believe they committed beyond a reasonable doubt.

Until recently, Louisiana was one of only two states that did not require the unanimous vote of a jury, a vestige of a Jim Crow-era law designed to negate the growing power of Black jurors.

In 2018, Louisiana residents voted to end the practice, and in 2020, the US supreme court found non-unanimous jury verdicts unconstitutional. But the court declined to make the ruling retroactive, leaving it up to Louisiana and Oregon (the only other state that allowed split juries) to decide whether people already serving time in such cases were entitled to new trials.

One night in 1993, Reddick was drinking in the same bar as Al Moliere in a small town south of New Orleans. A witness said he saw Reddick shoot Moliere later that night in the course of a robbery, but the story he told on the stand conflicted with multiple versions he had previously told police.

All the other evidence against Reddick – including a gun recovered months later with the initials “RR” carved into the handle – was circumstantial, said Jamila Johnson, one of his attorneys. In the more than 20 years he’s been in prison, he’s maintained he did not shoot Moliere.

Should Reddick win a new trial, many other incarcerated people in Louisiana may also be entitled to the same opportunity. But Johnson and the New Orleans non-profit the Promise of Justice Initiative have struggled to answer the surprisingly vexing question: who, exactly, was convicted by a non-unanimous jury in Louisiana?

“Our record-keeping in the south is horrible,” said Jason Williams, the district attorney in the parish that includes New Orleans. “It has been very difficult just to find all of the records and information necessary to do a complete review.”

That challenge was compounded by a deadline: even if the court rules in Reddick’s favor, only those who filed applications with the state courts within one year of the US supreme court’s 2020 ruling will have a shot at new trials. Anyone who discovered later that their jury was not unanimous would need legislators to pass a new law in order to ask for relief, Johnson says.

Racing the clock to find people sitting in prison due to split juries, three paralegals attended community meetings, visited prisons and sent letters trying to reach people who might have been sent to prison by a split jury. “Their job was talking to family members, walking them through documents that were in their closets. ‘You have a giant box. Let’s start in envelope one,’” said Johnson.

Eventually, the team filed petitions on behalf of about 1,000 people they could prove were convicted by split juries. In these cases, each juror’s vote was recorded in court transcripts or polling slips at the defendants’ original trials years, or even decades, ago.

Hundreds more had no recourse, said Sara Gozalo, a paralegal with the Promise of Justice Initiative, because the results of the polling were not recorded anywhere, or the polling never happened in the first place. “Maybe you were convicted by a 10-2,” Gozalo had to tell them. “You’ll never know.”

In most cases, district attorneys have opposed attempts to challenge these convictions, arguing that the supreme court’s ruling should not apply to older cases. But in more than 50 cases, prosecutors have been willing to revisit the convictions without waiting for a ruling in the Reddick case.

Williams, who was elected Orleans parish district attorney in 2020, campaigned on a promise to right many of the wrongs of his predecessors.

“There are a realm of cases that are wrongful convictions because, for example, they used a law that was specifically written to exclude Black voices from the jury – whether or not they actually did it,” said Emily Maw, who heads Williams’ Civil Rights Division. For 68 people, that meant vacating their convictions and negotiating pleas that resulted in less prison time.

Mark Isaac was convicted of second-degree murder in 1992 and had spent decades behind bars before a fellow prisoner at the Louisiana state penitentiary in Angola told him, “Man, check your paperwork, you might have 10-2,” Isaac recalled. He had maintained all along that he had acted in self-defense, and it wasn’t until he reached out to the Promise of Justice Initiative that he discovered two jurors may have agreed with him. His attorneys struck a deal with Williams’s office to have Isaac plead to the lesser charge of manslaughter and he was released with time served last year.

When Gozalo joined the Promise of Justice Initiative, she soon discovered that each parish in Louisiana had its own system of keeping records and its own rules about how to request them. Court clerks often demanded requests be faxed. Who uses fax machines in 2020, she wondered.

“I’m at an office with a fax machine, but what does an incarcerated person do?” Gozalo said. “These random rules … from one clerk to the next, seem arbitrary and almost violent to me – like little landmines that make it harder for people to fight their cases.”

The non-unanimous rule has its roots in the years after Reconstruction, known as the “Jim Crow era”, when white lawmakers were looking to dilute the civic power of newly enfranchised Black citizens.

In crafting the rule, “Our mission was, in the first place, to establish the supremacy of the White race in this State,” said delegates to the state’s 1898 constitutional convention. They determined how many Black people were likely to be seated on a jury, and then set the minimum number of votes so prosecutors could reliably obtain convictions over Black jurors’ objections. While the number of votes has changed over the years – first it was 9-3, then it was 10-2 – critics argue, the impact has not.

An investigative series by the Louisiana newspaper the Advocate analyzed six years of trial records, finding that Black defendants were more likely to be convicted by non-unanimous juries. A subsequent analysis of the same dataset by a Harvard professor as part of a 2018 court case found that Black jurors were significantly more likely to cast votes that don’t change the outcome of the case. He argued that “the non-unanimous jury verdict system operated today just as it was intended in 1898: to silence African-Americans on juries and to render their jury service meaningless.”

The state attorney general’s office and the Louisiana District Attorneys Association did not respond to requests for interviews. But in court filings, attorneys for the state argue that “the State’s interest in the finality of its non-unanimous verdicts is overwhelming and untainted by racial discrimination,” and warn that hundreds of new cases would flood the courts if the new rule were to be made retroactive.

“Evidence deteriorates, memories fade and witnesses become unavailable over time. It will be difficult – if not impossible – for the State to retry these cases,” they write. “Even if the State could retry some defendants, doing so would subject the victims of their crimes to fresh pain and difficulty.”

Gozalo and her colleagues say they are hopeful the state’s high court will recognize that people convicted by non-unanimous juries deserve new trials. “We’re not saying, ‘Free everyone,’” she said. “We’re saying, ‘Give everyone a fair trial.’”

This article was published in partnership with The Marshall Project, a nonprofit news organization covering the U.S. criminal justice system. Sign up for The Marshall Project newsletters, and follow them on Twitter, Instagram and Facebook.