Attorneys for condemned killer Warren Hill today asked the 11th Circuit U.S. Court of Appeals to stay his execution scheduled for next week.

Hill’s attorneys want the court to consider new evidence they claim show Hill is mentally retarded and ineligible for the death penalty. The U.S. Supreme Court in 2002 determined executing mentally retarded inmates to be unconstitutional.

Hill was convicted of a 1990 murder and earlier this year he came within two hours of being put to death before a federal appeals court called a halt.

Then last week, the state set a new execution date even though Georgia lacks the lethal injection drug and the U.S. Supreme Court has is still considering the previous bid to halt his execution.

Hill had been slated to die in February, but the 11th U.S. Circuit Court of Appeals in Atlanta stopped the execution so judges could consider whether evidence of his mental retardation was new and could be a basis for an appeal.

Hill was already serving a life sentence for murdering his 18-year-old girlfriend when, in 1990, he killed fellow inmate John Handspike at the Lee State Prison in South Georgia.

Hill’s capital punishment case has attracted international attention because three state experts who previously testified that Hill was faking his mental disabilities have come forward over the past year to say they were mistaken. The doctors — two psychiatrists and a psychologist — described their evaluations of Hill more than a decade ago as rush jobs. They said an improved understanding of mental disabilities led them to believe Hill is mildly mentally retarded.