AUSTIN (AP/CBSDFW.COM) – A Texas inmate facing execution wants a judge to rule the state improperly switched to a new lethal injection drug.

Cleve Foster is scheduled to be executed April 5 for the 2002 slaying of a Sudanese woman in Fort Worth. His lawyers hope a favorable ruling Friday will delay his execution.

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.

The Texas Tribune is reporting that Texas Department of Criminal Justice spokeswoman Michelle Lyons said officials there decided to follow the lead of Oklahoma and use the anesthetic drug pentobarbital in its lethal injection protocol.

Foster’s lawyers argue the change was made in private, violating rules that require 30-days’ notice and a chance for public comment. His lawyers want the judge to say the state must use the old drug, which is unavailable.

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.

(©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 This material may not be published, broadcast, rewritten, or redistributed.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.)

More From CBS Dallas / Fort Worth

Drip Pan: CBS Local App
Drip Pan: Weather App

Watch & Listen LIVE