HUNTSVILLE, Texas — The U.S. Supreme Court halted the execution Thursday of a black man convicted of a double murder in Texas 16 years ago after his lawyers contended his sentence was unfair because of a question asked about race during his trial.

Duane Buck, 48, was spared from lethal injection when the justices, without extensive comment, said they would review an appeal in his case. Two appeals, both related to a psychologist’s testimony that black people were more likely to commit violence, were before the court. One was granted; the other was denied.

Buck was sentenced to death for the fatal shootings of his ex-girlfriend and a man in her apartment in July 1995. Buck’s guilt is not being questioned, but his lawyers say the jury was unfairly influenced and that he should receive a new sentencing hearing. His attorneys appealed to the Supreme Court and Texas Gov. Rick Perry to block the execution, saying a psychologist testified that black people were more likely to commit violence.

Buck’s case is one of six convictions that then-Texas Attorney General John Cornyn — a political ally of Perry who is now a Republican U.S. senator — reviewed in 2000 and said needed to be reopened because of the racial reference. In the other five cases, new punishment hearings were held and each convict again was sentenced to die. State attorneys contend Buck’s case was different from the others and that the racial reference was a small part of larger testimony about prison populations.

Perry is a capital punishment supporter and as frontrunner for the Republican presidential nomination his actions now are coming under closer scrutiny. During his 11 years in office, 235 convicted killers in Texas have been put to death. His office said he has chosen to halt just four executions, including one for a woman who later was executed.

The reprieve from the nation’s highest court came nearly two hours into a six-hour window when Buck could have been taken to the death chamber. Texas officials, however, refused to move forward with the punishment while legal issues were pending.

His lawyers called to tell Buck of the reprieve and the inmate was praying in his cell when Texas Department of Criminal Justice spokesman Jason Clark approached.

“Praise the Lord!” Buck told Clark. “God is worthy to be praised. God’s mercy triumphs over judgment.

“I feel good.”

In its one-paragraph decision, the court said it stopped the punishment so it could further look at Buck’s request, known as a writ of certiori. If the court decided against the writ, the justices said the reprieve would be lifted, making Buck eligible for receiving a new execution date.

“We are relieved that the U.S. Supreme Court recognized the obvious injustice of allowing a defendant’s race to factor into sentencing decisions and granted a stay of execution to Duane Buck,” Kate Black, one of Buck’s attorneys, said. “No one should be put to death based on the color of his or her skin. We are confident that the court will agree that our client is entitled to a fair sentencing hearing that is untainted by considerations of his race.”

Buck was convicted of gunning down ex-girlfriend Debra Gardner, 32, and Kenneth Butler, 33, outside Houston on July, 30, 1995, a week after Buck and Gardner broke up. A third person, Buck’s stepsister, Phyllis Taylor, also was wounded, though she has since forgiven Buck and sought for his death sentence to be commuted to life in prison.

Buck’s attorneys went to the Supreme Court after losing appeals in lower courts. A clemency request to the Texas Board of Pardons and Paroles, all of whom are Perry appointees, also failed.

Perry was not in the state Thursday, meaning any final order to delay would have come from Lt. Gov. David Dewhurst. However the court’s ruling meant neither Perry nor Dewhurst had to act on a request from Buck’s lawyers that the governor use his authority to issue a one-time 30-day reprieve.

Assistant Attorney General Edward Marshall had told the Supreme Court on Thursday that Buck’s appeals were attempts to relitigate claims that every court, including the Supreme Court, already rejected.

“The record in Buck’s case reveals that no constitutional violation occurred during his sentencing trial,” he told the justices.

The execution would have been the second this week and the 11th this year in Texas. Two more Texas prisoners are set to die next week.