The U.S. Supreme Court on Monday declined to hear a case that could have tested Oregon's unusual system of allowing nonunanimous jury verdicts, dealing a blow to critics who claim the rule is unconstitutional.

Oregon and Louisiana will remain the only states to allow juries to convict most felony defendants with a 10-2 vote, though Oregon still requires a unanimous vote to find defendants guilty of murder.

The federal government and all other states require a 12-0 verdict for crimes such as manslaughter, rape and arson.

Lawyers for defendant Dale Lambert had petitioned the nation's high court to review Louisiana's jury law, claiming that such statutes deprive some defendants of equal protection under the law and should be ruled as unconstitutional.

Lambert, 30, was convicted in 2015 of second-degree murder by a 10-2 jury vote in Louisiana's Orleans Parish.

Previously, the Supreme Court upheld Oregon and Louisiana's jury laws in 1972 and has declined to hear cases challenging Oregon's 10-2 jury verdicts since as recently as 2009.

But criminal justice reform advocates — who believe nonunanimous juries are deeply flawed and punitive toward nonwhite defendants — had hoped the court's recent interest in cases involving race and juries could compel a new hearing.

That did not happen.

"While the Supreme Court chose not to hear the nonunanimous jury case, the fact remains that Oregon's nonunanimous jury system is a relic of anti-Semitism and xenophobia, and it dilutes minority voices today," said Aliza Kaplan, a professor at Lewis and Clark Law School in Portland, where she directs the Criminal Justice Reform Clinic.

The clinic submitted a brief in support of Lambert's petition, which was one of some 2,000 appeals submitted to the Supreme Court over the summer. Earlier this year, Kaplan published an article in the Oregon Law Review that argued how nonunanimous juries undermined the state's criminal just system.

The Supreme Court rejected all but a tiny fraction of the petitions it received, though it has agreed to take up a number of major criminal justice issues next year. Among them: cases that look at digital privacy, vehicle searches by police and plea bargains.

Louisiana's majority verdict system was adopted during the state's 1898 constitutional convention to diminish the influence of black jurors upon verdicts, scholars claim.

In Oregon nearly four decades later, it was a sensational murder trial involving a Jewish suspect that prompted voters in 1934 to adopt the nonunanimous jury system, according to advocates and legal scholars.

Though declined by the high court, Oregon legislators still have the ability to refer a proposal to voters to change the system back to a 12-0 vote, which would likely spark a multimillion-dollar ballot fight. State lawmakers have not tackled the issue of nonunanimous juries since it first recommended a public vote in 1934

In an interview with The Oregonian/OregonLive last month, Kaplan said the rule is likely to limit evidence-based jury deliberations and increase wrongful convictions. It may also marginalize minority jurors whose votes aren't needed, she said.

Some of Oregon's most seasoned prosecutors, who support the state's unique jury system, disagree with that characterization.

"They simply result in fewer hung juries and not more convictions," said Clatsop County District Attorney Josh Marquis. "This system empowers jurors. And victims of crimes."

-- Shane Dixon Kavanaugh

skavanaugh@oregonian.com

503-294-7632 II @shanedkavanaugh