Washington (CNN) The Supreme Court said Monday that unanimous jury verdicts are required in state criminal trials for serious offenses, handing a victory to criminal defendants including petitioner Evangelisto Ramos, who was convicted of murder in Louisiana on a 10-2 vote.

Ramos argued that Louisiana's non-unanimous jury provision violated his federal constitutional right to trial by jury and that the law had racist roots meant to diminish the votes of minority jurors.

Justice Neil Gorsuch penned the opinion and was joined in key parts by Justices Ruth Bader Ginsburg, Sonia Sotomayor, Stephen Breyer and Brett Kavanaugh.

"We took this case to decide whether the Sixth Amendment right to a jury trial -- as incorporated against the States by way of the Fourteenth Amendment -- requires a unanimous verdict to convict a defendant of a serious offense," Gorsuch wrote.

"One of these requirements was unanimity," he said, "a jury must reach a unanimous verdict in order to convict."

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