The Supreme Court’s ruling in June that extended the Second Amendment right to bear arms to states and localities has spawned follow-up litigation testing gun regulations across the country.

But one lawsuit flowing from McDonald v. Chicago now before the Supreme Court has nothing to do with gun rights. Instead, Herrera v. Oregon asks the justices to strike down Oregon’s long-standing practice that allows juries to convict defendants in criminal cases by less than a unanimous vote. Oregon and Louisiana, alone among the 50 states, permit non-unanimous verdicts in criminal cases, even though the Sixth Amendment has long been presumed to require unanimity, at least in federal juries.

How did a challenge to non-unanimous juries in Oregon originate in the Second Amendment case? It’s because of a little-noticed footnote in the McDonald decision in which Justice Samuel Alito Jr. reviewed the history of the Court’s full-fledged “incorporation” or application of provisions of the Bill of Rights to the states. Alito noted “one exception to this general rule,” namely jury unanimity under the Sixth Amendment.

The reason for this anomaly is Apodaca v. Oregon, a 1972 Supreme Court decision that featured what Alito described as “an unusual division among the justices.” In that case, eight justices agreed that the Sixth Amendment applies to the federal and state governments identically on the question of jury unanimity. The catch was that four believed the Sixth Amendment required jury unanimity in both state and federal trials, while the other four believed it did not require unanimity at either level. Justice Lewis Powell Jr., not surprisingly, was the tie-breaker whose opinion ruled the case, and he split the difference: He said jury unanimity was required at the federal level, but not for the states.

That is how things have remained ever since: No other states leapt at the chance to allow non-unanimous verdicts, and occasional challenges to Oregon’s practice were turned away by the high court — even though more recent rulings like Apprendi v. New Jersey and Blakely v. Washington contained language that embraced jury unanimity as an important element of Sixth Amendment protections.

But Eugene Volokh of UCLA Law School read the footnote about jury unanimity in the McDonald case as a signal, and possibly an invitation, from the Court suggesting it might be time for a review of Apodaca. So he wrote about the issue on his widely read blog Volokh Conspiracy. “How else do you find new cases these days? It came to me through the blog,” Volokh joked

Sure enough, he soon heard from the local lawyer for Alonso Herrera, who was prosecuted in Oregon for unauthorized use of a vehicle and possession of a stolen vehicle. The jury convicted him by a 10-2 vote on one charge, and acquitted him 11-1 on the other. As defense lawyers often do in Oregon, Herrera’s lawyer had preserved a challenge on the issue of jury unanimity by asking the trial judge to instruct the jury that the verdict needed to be unanimous. The trial judge denied the request, and Oregon appeals courts rejected his appeals.

With the high court’s explicit reference to Apodaca in McDonald, Volokh is hoping the Court will review the Herrera case even though it has rejected other appeals to Oregon’s non-unanimous juries in the past.

Even originalists like Justice Antonin Scalia embrace juror unanimity, Volokh says. It is not specifically mentioned in the Sixth Amendment, but is revered as part of a rich and lengthy tradition in Anglo-American legal history, says Volokh. “It’s been around for centuries.” Volokh cites William Blackstone’s commentaries, the trial of Aaron Burr, lectures by Justice James Wilson, and Justice Joseph Story’s treatise as evidence that unanimity was viewed as “indispensable.”

Oregon first adopted non-unanimous juries in a 1934 ballot initiative, says University of Oregon School of Law professor Carrie Leonetti. The intention was apparently to make it easier to convict defendants without meeting the “beyond a reasonable doubt” standard.

But Leonetti does not believe Oregonians now are generally aware of the practice unless they’ve served on juries themselves. “If I called my mother right now, I don’t think she would be aware of it, and I teach about it. I don’t think there is any real constituency in support of non-unanimous juries.”

Leonetti, who is working on a brief in support of Volokh’s petition, says studies have shown that requiring juror unanimity makes for much better jury deliberations. When one or more juror dissents, she adds, “it’s usually not just a crackpot holdout. They are really worried about the fairness of the verdict.” When non-unanimous verdicts are allowed, she said, “no credence is given to the dissenting juror,” and the verdict is announced hurriedly. “Dissenting jurors deserve to be listened to.”

Tony Mauro can be contacted at tmauro@alm.com.