DALLAS -- A DNA test on a strand of hair has cast doubt on the guilt of a Texas man who was executed 10 years ago during George W. Bush's final months as governor for a liquor-store robbery and murder.

The single hair had been the only piece of physical evidence linking Claude Jones to the crime scene. But the DNA analysis found it did not belong to Jones and instead may have come from the murder victim.

Barry Scheck, co-founder of the Innocence Project, a New York legal center that uses DNA to exonerate inmates and worked on Jones' case, acknowledged that the hair doesn't prove an innocent man was put to death. But he said the findings mean the evidence was insufficient under Texas law to convict Jones.

The other primary evidence against Jones came from one of two alleged accomplices: Timothy Jordan, who did not enter the liquor store but was believed to have planned the robbery and provided the gun. Jordan testified that Jones told him he was the triggerman. However, under Texas law, accomplice testimony isn't enough to convict someone and must be supported by other evidence. That other evidence was the hair.

"There was not enough evidence to convict, and he shouldn't have been executed," Scheck said.

The final determination of whether Jones was wrongly executed would be up to a judge.

Scheck, a death-penalty opponent, said the case shows that the risk of a tragic mistake by the legal system is just too high. "Reasonable people can disagree about the moral appropriateness of the death penalty. The issue that has arisen is the risk of executing the wrong person," he said.

San Jacinto County District Attorney Bill Burnett, who prosecuted the case, died earlier this year.

"I still think he was guilty," Joe Hilzendager, the murder victim's brother, said Thursday. "I think they executed the right man."

Former San Jacinto County Sheriff Lacy Rogers also said he is convinced Jones committed the crime -- "without a doubt in my mind."

In the nearly 35 years since capital punishment was reinstated in the U.S., there has never been a case in which someone was definitively proven innocent after being executed. That would be an explosive finding, since it would corroborate what opponents of the death penalty have long argued: that the legal system is flawed and that capital punishment could result in a grave and irreversible error.

Jones was condemned to die for the 1989 killing of liquor store owner Allen Hilzendager, who was shot three times outside the town of Point Blank, population 559. Authorities said his getaway driver was Danny Dixon, previously convicted of shooting a girl between the eyes and burying her in a cemetery.

During the trial, a forensic expert testified that he examined the hair under a microscope and concluded that it could have come from Jones but not from Dixon or the store owner. No DNA test was performed for the trial.

Prosecutors also hammered on Jones' brutal past. While serving a 21-year prison sentence in Kansas, he poured a flammable liquid on his cellmate and set him on fire, killing him.

Jones was executed in December 2000 at age 60, the last person put to death during Bush's time as governor. In his final statement, Jones did not acknowledge guilt but told the Hilzendager family he hoped his death "can bring some closure to y'all. I am sorry for your loss and hey, I love all y'all. Let's go."

At the time, Jones was pressing the governor's office for permission to do a DNA test on the hair. But as the execution drew near, the briefing Bush got from his staff didn't include the request for the DNA test, and Bush denied a reprieve, according to state documents obtained by the Innocence Project.

Scheck said he believes "to a moral certainty" that Bush would have granted a 30-day reprieve had he known Jones was seeking DNA testing. A spokesman for Bush, who is on a book tour, did not immediately respond to a request for comment.

"It is absolutely outrageous that no one told him that Claude Jones was asking for a DNA test," Scheck said. "If you can't rely on the governor's staff to inform him, something is really wrong with the system."

Bush had previously shown a willingness to test DNA evidence that could prove guilt or innocence in death penalty cases. Earlier in 2000, he had granted a reprieve to a death row inmate so that Scheck and other attorneys could have evidence tested. The test confirmed the man's guilt and he was executed.

More than three years after the execution, Jordan recanted his claim that Jones admitted to being the triggerman. In an affidavit, Jordan said he was scared, and "I testified to what they told me to say."

Texas is far and away the No. 1 death penalty state, having executed 464 people over the past three decades.

The Jones case is second time this year that the guilt of an executed Texas inmate was thrown into doubt. Cameron Todd Willingham was put to death in 2004 after being convicted of setting the 1991 fire that killed his three daughters. But several renowned experts said earlier this year that the investigation of the fire was so flawed that the arson finding can't be supported.

The hair in the Jones case was tested 10 years after the execution at the request of his son Duane, along with the Innocence Project, other groups and The Texas Observer magazine. Prosecutors agreed to the testing.

"At the very least, if they had tested his DNA before he was executed, he could have gotten a new trial or his sentence overturned or changed," Duane Jones said Thursday. He said his father "told me that he had robbed banks, that he was a thief. But he wasn't a person who would go out and murder someone on the street."