A sharply divided U.S. Supreme Court on Thursday gave condemned Baton Rouge cop killer Kevan Brumfield new hope for escaping a death sentence, ordering an appeals court to fully assess a federal judge’s finding that the inmate is intellectually disabled and thus ineligible to be executed for the 1993 ambush killing of Cpl. Betty Smothers.

Dissenters accused the high court majority of distorting federal law and intruding upon Louisiana’s sovereign right to enforce its criminal law and its courts’ judgments.

A three-judge panel of the 5th U.S. Circuit Court of Appeals had reversed U.S. District Judge James Brady’s 2012 ruling early last year, saying there was no need for the judge to hold a 2010 hearing on Brumfield’s claim that he is mentally impaired and therefore cannot be put to death.

The 5th Circuit judges determined that state District Judge Richard Anderson in 2003 properly denied Brumfield’s request for an evidentiary hearing in Baton Rouge state court on his claim of intellectual disability, which mental health professionals and the courts previously called mental retardation. More than a decade ago, the Supreme Court barred the execution of people found to be intellectually impaired.

But the Supreme Court, in a 5-4 vote Thursday, said Anderson’s decision was wrong and that Brumfield was entitled to have his disability claim considered in federal court.

In the majority opinion, Justice Sonia Sotomayor wrote that there was sufficient evidence to support a court fully exploring Brumfield’s intellectual capacities at the time of the murder.

“All told, then, the evidence in the state-court record provided substantial grounds to question Brumfield’s adaptive functioning,” she wrote.

Nick Trenticosta, one of Brumfield’s attorneys, said the court’s decision sends the case back to the 5th Circuit for a ruling on whether Brady was wrong or correct in finding Brumfield intellectually disabled.

“The truth is he’s intellectually disabled and he’s ineligible to be executed,” Trenticosta said by phone while driving to meet with Brumfield at the Louisiana State Penitentiary at Angola. Later, Trenticosta reported that Brumfield was “extremely pleased” with the Supreme Court decision.

East Baton Rouge Parish District Attorney Hillar Moore III expressed disappointment with the high court’s finding but said he remains confident that Brumfield failed to prove his claim of intellectual disability.

“This office will continue to actively pursue the death penalty and is confident that we will prevail” at the 5th Circuit and Supreme Court, he added.

Trenticosta said Brumfield’s case will surely return to the Supreme Court after the appellate court makes a decision.

The 5th Circuit did not review Brady’s conclusions about Brumfield’s capacities. But the appeals court panel hinted they would not look favorably on the larger claim. They noted in a January 2014 ruling that, “Even if we were to consider the new evidence presented to the (federal) district court, we likely would hold that Brumfield failed to establish” that he is intellectually disabled.

Justice Clarence Thomas penned a fiery dissent, capping it off with a photo of a uniformed Smothers standing next to a police car.

A footnote to the dissent noted that Smothers, six years before her death, caught Brumfield stealing and gave him a chance to turn his life around — “a chance he unfortunately did not take.”

Smothers, 36, was the single mother of six children. Her oldest, Warrick Dunn, grew up to make a name for himself in football, starring on the Catholic High School team, playing for Florida State University and capping off a career in the NFL. His mother was killed two days after Dunn’s 18th birthday.

Dunn has said previously that Brumfield’s use of mental disability as a defense is “offensive and morally wrong.”

Thomas called the two men — the killer and son — a “study in contrasts.”

“On the one hand, we have Kevan Brumfield, a man who has spent the last 20 years claiming that his actions were the product of circumstances beyond his control,” Thomas wrote, referring to Brumfield’s claim of a disadvantaged background. “On the other hand, we have Warrick Dunn, who responded to circumstances beyond his control by caring for his family, building a professional football career, and turning his success on the field into charitable work off the field.”

In a passage about Dunn, Thomas noted some examples of the football player’s charity work, describing at length the groups he has been involved with.

But Sotomayor in her opinion said Brumfield presented evidence that he was at risk of “neurological trauma” at birth, was diagnosed with a learning disability and placed in special education classes, was committed to mental health facilities and given powerful medication, reads at a fourth-grade level and cannot process information.

“It is critical to remember ... that in seeking an evidentiary hearing, Brumfield was not obligated to show that he was intellectually disabled, or even that he would likely be able to prove as much,” Sotomayor wrote. “Rather, Brumfield needed only to raise a ‘reasonable doubt’ as to his intellectual disability to be entitled to an evidentiary hearing.”

Sotomayor was joined by Justices Stephen Breyer, Ruth Bader Ginsburg, Elena Kagan and Anthony Kennedy.

Thomas and his fellow dissenters — Chief Justice John Roberts and Justices Samuel Alito and Antonin Scalia — argued the majority over-emphasized Brumfield’s special ed classes.

“The majority places special weight on Brumfield’s placement in ‘special education’ classes, but the record explains that he was placed in behavioral disorder classes not because he had a low capacity to learn, but because he had a high capacity to make trouble,” Thomas stated.

Thomas also charged that the majority showed a “disregard for the human cost of its decision.”

“It spares not a thought for the 20 years of judicial proceedings that its decision so casually extends,” Thomas said of the majority’s ruling. “It spares no more than a sentence to describe the crime for which a Louisiana jury sentenced Brumfield to death. It barely spares the two words necessary to identify Brumfield’s victim, Betty Smothers, by name.

“She and her family — not to mention our legal system — deserve better.”

Sotomayor countered the court’s majority does not deny that Brumfield’s crimes “were terrible, causing untold pain for the victims and their families.”

“But we are called upon today to resolve a different issue,” she wrote.

Brumfield, now 42, and Henri Broadway, both of Baton Rouge, were convicted in 1995 and sentenced to death for ambushing Smothers on Jan. 7, 1993, as she drove a grocery store assistant manager to make a night bank deposit on Jefferson Highway. Smothers was working as an off-duty security officer at the time. The assistant manager also was shot outside the bank, but survived.