The U.S. Supreme Court on Wednesday blocked Georgia's attempt to again prosecute an accused murderer whose trial ended in contradictory verdicts, finding that "an acquittal is an acquittal" regardless of a simultaneous guilty verdict for the same offense.

In a unanimous decision authored by Justice Ketanji Brown Jackson, the high court sided with a man named Damian McElrath who killed his mother and was subsequently found not guilty by reason of insanity of malice-murder, as well as guilty but mentally ill on charges of felony murder and aggravated assault.

"McElrath now maintains that the Fifth Amendment's double jeopardy clause prevents the state from retrying him for the crime that had resulted in the 'not guilty by reason of insanity' finding. Under the circumstances presented here, we agree," Wednesday's opinion said, rejecting the Georgia Supreme Court's conclusion that a new trial was needed because the split verdicts were "repugnant."

"We are very pleased to have a unanimous decision in favor of our client," Wiley Rein LLP partner Richard A. Simpson, who argued the case for McElrath, told Law360 on Wednesday. "We were optimistic based on the oral argument, and it is gratifying to see that the court agreed with our arguments."

Simpson also called the holding "an important precedent" that will protect defendants acquitted of one charge from being retried "even if the acquittal is repugnant to a conviction on a different charge."

The double jeopardy clause stipulates that "no person shall … be subject for the same offense to be twice put in jeopardy of life or limb." Although it's firmly established that acquittals are final, McElrath's case presented the question of what, exactly, qualifies as an acquittal.

Georgia conceded that the not guilty verdict would be valid if it hadn't been accompanied by the guilty verdict. But the state insisted that the existence of conflicting verdicts premised on different mental states warranted a double jeopardy exception in the form of scrutiny and potential nullification of the jury's verdicts.

In rejecting that contention, the justices on Wednesday said they "have long recognized that, while an acquittal might reflect a jury's determination that the defendant is innocent of the crime charged, such a verdict might also be 'the result of compromise, compassion, lenity or misunderstanding of the governing law.'"

"Whatever the basis, the double jeopardy clause prohibits second-guessing the reason for a jury's acquittal," the high court held.

Ultimately, the jury's finding that McElrath was not guilty by reason of insanity means that the prosecution failed to establish criminal culpability, and the finding was therefore just like any other acquittal, Wednesday's opinion said.

The high court's holding is unlikely to apply frequently in criminal trials, largely because Georgia's "repugnancy" rule is unusual and has rarely been applied even within the Peach State.

Moreover, Justice Samuel Alito penned a concurring opinion Wednesday to emphasize his view that the opinion simply reinforced the longstanding prohibition on appellate review of acquittals. In that concurrence, Justice Alito also distinguished McElrath's case from a situation in which a trial judge rejects inconsistent verdicts and tells jurors to resume deliberations.

"Nothing that we say today should be understood to express any view about whether a not guilty verdict that is inconsistent with a verdict on another count and is not accepted by the trial judge constitutes an 'acquittal' for double jeopardy purposes," Justice Alito wrote.

McElrath challenged the state's repugnancy rule after the verdicts in 2017 in relation to the 2012 stabbing death of his adoptive mother, Diana McElrath. Under Georgia law, a "guilty but mentally ill" verdict means the jury found the defendant guilty beyond a reasonable doubt but believed the defendant should be placed in psychiatric care before serving their prison term.

On appeal, the Georgia Supreme Court vacated all verdicts against McElrath after finding they were contradictory and "repugnant" under state law. The court ordered a new trial in McElrath's case, which he claimed violated the double jeopardy clause by subjecting him to an unconstitutional retrial.

Georgia defended its rule by arguing it was established to protect defendants in instances where juries find "inherently contradictory" facts and return illogical verdicts.

A spokesperson for the Georgia Attorney General's Office had no immediate comment on Wednesday.

McElrath is represented by Richard A. Simpson and Elizabeth E. Fisher of Wiley Rein LLP, H. Maddox Kilgore and Carlos J. Rodriguez of Kilgore & Rodriguez LLC and F. Andrew Hessick.

Georgia is represented by Stephen J. Petrany, Ross W. Bergethon, Justice T. Golart, James E. Barrett and Paul R. Draper of the Georgia Attorney General's Office.

The case is McElrath v. Georgia, case number 22-721, in the Supreme Court of the United States.

--Editing by Alyssa Miller.

Update: This story has been updated with more details and with comments from counsel for McElrath.