Richard Wolf

USA TODAY

WASHINGTON — The Supreme Court agreed Monday to decide how the state that leads the nation in executions determines who is mentally competent enough to die.

The justices at first announced that they would take up a more significant issue in the Texas case — whether executing a condemned prisoner after decades on death row constitutes cruel and unusual punishment. But more than two hours after issuing its original order, the court corrected its mistake.

The Texas case of Bobby James Moore dates back to 1980, when he shot and killed a grocery store clerk during a botched robbery. His attorneys say Moore's mental competency was gauged using a decades-old definition of intellectual disability, rather than current medical standards.

The court has tightened sentencing rules for people with intellectual disabilities since 2002, when it issued a landmark decision declaring it unconstitutional for states to execute them. In 2014, it barred states from using a single, strict IQ standard to determine a prisoner's competency.

The Texas case could tighten those standards further. Moore's attorneys say his mental competency was gauged using a 23-year-old definition of intellectual disability, rather than modern medical standards.

Moore's lawyers also had argued that executing someone after so long on death row is unconstitutional. "Prolonged confinement for many decades under sentence of death represents a sword of Damocles perpetually hanging just above the condemned individual’s head," Moore's lead attorney, Clifford Sloan, argued in court papers.

Earlier Monday, the court announced it had granted the full petition. But shortly before noon, it revised its order, specifying that it would consider only the intellectual disability question.

Texas leads the nation in executions with 537 since 1976, nearly five times the total of any other state.

In a separate Texas death penalty case, the justices also agreed to consider whether a condemned inmate can appeal his sentence because his original trial attorney allowed testimony that he was more likely to be dangerous in the future because he is African American.

The death penalty has divided the court for decades. That was most evident last June, when the justices ruled 5-4 that states could continue to use a controversial sedative as part of their lethal injection protocols. Four justices spoke up — two in favor, two against — and Justice Stephen Breyer said the court should consider the overall constitutionality of the death penalty.

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Breyer raised four issues — the potential for mistakes, racial and other disparities, decades-long delays, and increasing numbers of states and counties abandoning capital punishment. Justice Ruth Bader Ginsburg signed on to his dissent.

"Rather than try to patch up the death penalty's legal wounds one at a time, I would ask for full briefing on a more basic question: whether the death penalty violates the Constitution," Breyer wrote.

Since then, the court has refused to take on a case testing whether capital punishment remains constitutional. But viewing Breyer's dissent as an invitation, lawyers for death-row inmates continue to send up new cases.

The case is likely to be scheduled for the fall, when the court still may be shorthanded following the death in February of Justice Antonin Scalia. The key vote may belong to Justice Anthony Kennedy, who has sided with the court's liberals on death penalty cases involving intellectual disability. He wrote the 2014 decision in a Florida case.

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