The U.S. Supreme Court on Monday declined to take up the case of a Georgia death row inmate whose lawyers say he is mentally disabled and shouldn't be executed.
Warren Hill's lawyers asked the Supreme Court in May for a review after three doctors who initially said Hill was not mentally disabled changed their opinions.
Hill was sentenced to die for the 1990 beating death of fellow inmate Joseph Handspike. Hill beat Handspike with a nail-studded board while his victim slept, authorities said. At the time, Hill was serving a life sentence for the 1986 slaying of his girlfriend, Myra Wright, who was shot 11 times.
Three state experts who testified in 2000 that Hill was not mentally disabled submitted sworn statements in February saying they had been rushed in their evaluation at the time, that they now have more experience and that there have been scientific developments since then. All three reviewed facts and documents in the case and write that they now believe Hill is mentally disabled.
Brian Kammer, a lawyer for Hill, said he was "gravely disappointed" by the high court's denial.
"Mr. Hill has been procedurally barred from proving his exemption from capital punishment, which is why he brought his case to the U.S. Supreme Court, in the hopes that the court would ensure that the evidence of his intellectual disability would be heard," Kammer said. "It is tragic that our highest court has failed to enforce its own command that persons with mental retardation are categorically ineligible for the death penalty."
The execution of mentally disabled offenders is prohibited by state law and a 2002 U.S. Supreme Court decision.
Georgia has the strictest-in-the-nation standard for death row inmates seeking to avoid execution, requiring them to prove their mental disability beyond a reasonable doubt. The state has said repeatedly that Hill's lawyers have failed to meet that standard and has dismissed the doctors' new testimony, saying it isn't credible.
Three separate death warrants have been issued for Hill, but his execution has repeatedly been delayed to give courts more time to consider various challenges.
He was most recently set to be put to death in July, but the execution was halted by a Fulton County Superior Court judge who granted an injunction so the court system could review the constitutionality of a law barring the release of information about where Georgia obtains its supply of execution drugs.
The state has appealed that decision to the Georgia Supreme Court, which has said it will hear the case.