Richard Dale Stokley

Photo courtesy of Arizona Department of Corrections

PHOENIX - An Arizona inmate's lawyers on Friday asked the U.S. Supreme Court to block his scheduled execution Wednesday, arguing that lower courts unfairly denied him a hearing on potential evidence for possible leniency in sentencing for the brutal killing of two 13-year-old girls.

Richard Dale Stokley was sentenced to death for the 1991 murders in rural Cochise County of Mandy Meyers and Mary Snyder.

The girls disappeared from a July 4 holiday weekend community campout. Their bodies were found in a partly flooded mine shaft in a ghost town. They had been raped, beaten, stabbed, strangled and stomped.

The Attorney General's Office will file a response by Monday asking the justices to allow the execution to take place as scheduled, said Kent Cattani, the state's top death penalty prosecutor.

The response will argue that courts did consider sentencing evidence submitted on Stokley's behalf, Cattani said.

"They may not have given it the weight the inmate wanted," Cattani said. "The requirement is simply that they consider it."

A federal appeals court has said it won't consider additional requests from Stokley, and a Supreme Court order denying Stokley's stay request apparently would allow the execution to go forward.

Stokley has already declined efforts asking the state clemency board to recommend that Gov. Jan Brewer commute his sentence to life in prison or delay his execution.

His current lawyers argue that an attorney who represented Stokley early in the appeal process in state court barely investigated his case, effectively abandoning her client.

Evidence that could have influenced the sentencing was not adequately proposed or considered, including that an abusive childhood and brain damage diminished Stokley's ability to tell right from wrong, the lawyers said in court papers.

Papers filed with the Supreme Court said Stokley is entitled to a new hearing based on a 2011 Supreme Court ruling involving an Alabama death row inmate.

That ruling said the Alabama inmate was entitled to a hearing because a New York law firm effectively abandoned the inmate when it returned unopened notices it received in his case.

The 9th U.S. Circuit Court of Appeals recently rejected Stokley's appeal claiming abandonment, saying he did have a lawyer and that courts did consider so-called "mitigating" evidence.

Dissenting judges said the majority used the wrong legal standard for deciding whether Stokley was entitled to a new hearing.

Harriette Levitt, the Tucson lawyer accused by Stokley's current lawyers of abandoning him, did not immediately return a call for comment.

A second man, Randy Brazeal, pleaded guilty to second-degree murder in the killings. He was released in July 2011 after serving 20 years in prison.