HUNTSVILLE (AP) – The U.S. Supreme Court has blocked the first scheduled execution of a Texas death row inmate using pentobarbital.

Cleve Foster was to have been executed Tuesday evening for the 2002 slaying of a Sudanese woman in Fort Worth — the first Texas execution since the state switched to pentobarbital in its lethal three-drug mixture.

Texas announced in March it would use a new drug in lethal injections after a shortage made the old one unavailable. The only American producer of sodium thiopental, Illinois-based Hospira Inc., announced in January it would stop selling the drug. Instead of sodium thiopental, the state decided to use the anesthetic drug pentobarbital in its lethal injection protocol.

Foster’s attorney, Clint Broden, says the stay is not related to the drug protocol, but rather to his client’s representation at trial. “The reason for the stay is so the Supreme Court can consider whether it wants to address the issue of whether a person has the right to effective assistance of council,” said Broden.

On Tuesday morning, the high court agreed to reconsider its January order denying the 47-year-old’s appeal. That appeal raised claims of innocence and poor legal help during his trial and early stages of his appeals.

Foster’s lawyers also argued that Texas prison officials violated administrative procedures when they announced the switch to pentobarbital from sodium thiopental.

Foster and a companion, Sheldon Ward, were both given the death sentence for raping and fatally shooting Nyanuer “Mary” Pal in Fort Worth. The 28-year-old woman’s body was found in a ditch by a work crew hours after the men were seen following her from a pool hall.

The pentobarbital substitution has already been used in executions in Oklahoma and Ohio.

(©2011 CBS Local Media, a division of CBS Radio Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)

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