WASHINGTON — The Supreme Court is ordering a federal appeals court to re-examine the case of a convicted killer in Ohio whose death sentence was thrown out after he was found to be mentally disabled.

In an unsigned opinion Monday, the justices said that the federal appeals court in Cincinnati applied the wrong standard when it concluded that inmate Danny Hill was ineligible to be executed.

The high court said the appellate judges wrongly relied on a recent Supreme Court decision, but should have instead based their decision on rulings that were in effect at the time that state courts judged Hill not to be mentally disabled.

The Supreme Court banned the execution of mentally disabled people in 2002, but states still retain significant discretion in assessing mental disability.