Lawyers want Supreme Court to block Texas from executing man

This undated handout photo provided by the Texas Department of Criminal Justice shows Robert Pruett. On Tuesday, April 28, 2015, Pruett, 35, is scheduled to die for the fatal stabbing of corrections officer Daniel Nagle more than 15 years ago. According to prosecutors, Pruett was angry at Nagle for writing him up for a disciplinary infraction for trying to take his brown bag peanut butter sandwich to a prison recreation yard in violation of rules. (AP Photo/Texas Department of Criminal Justice)
This undated handout photo provided by the Texas Department of Criminal Justice shows Robert Pruett. On Tuesday, April 28, 2015, Pruett, 35, is scheduled to die for the fatal stabbing of corrections officer Daniel Nagle more than 15 years ago. According to prosecutors, Pruett was angry at Nagle for writing him up for a disciplinary infraction for trying to take his brown bag peanut butter sandwich to a prison recreation yard in violation of rules. (AP Photo/Texas Department of Criminal Justice)

HUNTSVILLE, Texas (AP) — Attorneys for an inmate convicted in a prison guard’s death are asking the U.S. Supreme Court to halt his scheduled execution.

They want justices to review whether lower courts properly denied a federal civil rights lawsuit that sought additional DNA testing in Robert Pruett’s case and whether a prisoner who claims actual innocence, as Pruett does, can be put to death.

The execution is set for Thursday.

The 38-year-old Pruett was already serving 99 years for a neighbor’s killing when he was convicted in the 1999 death of corrections officer Daniel Nagle at a prison southeast of San Antonio. Nagle was stabbed repeatedly with a metal rod and an autopsy showed the assault caused a heart attack that killed him.

Pruett would be the sixth Texas prisoner executed this year.

In 2015, Pruett was scheduled for execution but a judge granted him a reprieve.