PENDLETON — John McKenzie Mattila of Weston gets another shot at a manslaughter trial thanks to the change in U.S. law requiring unanimous jury verdicts.

The U.S. Supreme Court in 2020 in Ramos v. Louisiana ruled the Sixth Amendment to the Constitution requires guilty verdicts for criminal trials be unanimous. Umatilla County District Attorney Dan Primus said his office has handled a handful of these cases already.

“We’re taking these cases as they come back,” he said.

A jury in March 2020 convicted Mattila, 26, after three hours of deliberation, of first- and second-degree manslaughter for driving drunk and causing the death of Adelaida Solis Torres on the night of Feb. 22, 2019.

Matilla faced four counts in all: first-degree manslaughter, second-degree manslaughter, hit-and-run involving a person and driving under the influence of intoxicants. Primus said the jury was unanimous only on the hit-and-run.

The jury voted 11-1 to convict Mattila of first-degree manslaughter and second-degree manslaughter and voted 10-2 on the DUII.

Oregon along with Louisiana were the only two states not requiring unanimous verdicts for criminal trials until the Supreme Court decision. Primus said it’s hard to speculate what the outcome of Mattila’s trial would have been if Oregon also required unanimous verdicts at the time. Perhaps the Mattila trial would have ended with a conviction, he said, or maybe a hung jury.

Now, he said, the trial process is starting over.

The Oregon Court of Appeal reversed the verdicts on Sept. 27, according to court documents, and Mattila on Sept. 29 returned to the Umatilla County Jail, Pendleton, from the Oregon Department of Corrections. Circuit Judge Jon Lieuallen has set Matilla’s bail at $500,000, and he has a pretrial conference Friday, Oct. 8.

“We’re in the process right now of meeting with the victims about the circumstances and the posture of the case — why it’s back,” Primus said.

Dan Pacheco, the deputy district attorney who helped prosecute Mattila the first time, is back on the case, and Primus is joining him, replacing another deputy district attorney who has left.

Primus also said while the case has come back for retrial, that is not the only option. The restart also opens the door to negotiations for a deal, an option Primus said his office has pursued in a few other Ramos-related cases.