Richard Cobb never denied using a 20-gauge shotgun to kill one of three people he and another man abducted during a holdup of an East Texas convenience store almost 11 years ago.
But Cobb couldn't convince a Cherokee County jury that he was forced into the shooting because of threats from his companion, and he was convicted of capital murder in the death of 37-year-old Kenneth Vandever.
Cobb's lethal injection is set for Thursday evening. It would be the fourth execution this year in Texas and third this month.
"There's really nothing left to do," Cobb, 29, told the Jacksonville Daily Progress last month from death row. "There's no getting away from it. At the same time, I don't want to die, but I'm ready to die."
The crime was "the biggest mistake of my life," he said.
Lawyers from the University of Houston-based Texas Innocence Network asked the U.S. Supreme Court to halt the punishment, contending a prison expert called by prosecutors during the punishment phase of Cobb's trial falsely testified how Cobb would have more freedom in prison if he were sentenced to life. The Texas Court of Criminal Appeals ordered reviews of those punishments in at least four other similar cases, but refused to look at Cobb's case, Cobb's lawyers said.
"He is entitled to be treated the same way that other similarly situated inmates are treated," the appeals attorneys told the high court Wednesday.
On Sept. 2, 2002, Vandever and two women were abducted from a store in Rusk, about 120 miles southeast of Dallas, and taken to a field about 10 miles away. There, one of the women was raped and all three were shot and left for dead. Vandever did, but the two women survived and testified against their attackers.
A day later, Cobb — 18, a high school dropout and already on probation for auto theft — and companion Beunka Adams were arrested in Jacksonville, about 25 miles away.
"I'm guilty of the crime," Cobb told The Associated Press in 2004 after arriving on death row. "I was young, dumb and made a mistake."
Adams, 29, who Cobb met at boot camp when they were in ninth grade, was executed a year ago for his participation in the abduction-slaying.
Cobb was accused of firing the shot that killed Vandever, who frequented the store and would do things like take out the trash. Vandever previously had suffered injuries in an auto accident that left him with the mental capacity of a child.
Adams was accused of shooting the women, who managed to walk to houses nearby for help.
"What we tried to do is use the defense of duress, that the other fellow involved made him do it," William House, one of Cobb's trial attorneys, said. But Cobb, under cross-examination, said he never mentioned in his confession to authorities any coercion by Adams.
"The only thing he stated that gave him any hesitation is that he stepped back a few feet because he didn't want the blood to splatter on him," Elmer Beckworth, who prosecuted Cobb, said. "Then at trial, all of a sudden, Adams forced him — while he (Cobb) had the gun."
The two survivors said they never heard Adams threaten Cobb. A fellow jail inmate testified Cobb told him he planned to blame the murder on Adams.
Cobb testified he began using drugs at age 12 and turned to robbery to pay off a drug debt.
At least 11 other Texas inmates have executions scheduled for the coming months, including three in May.