During a sentencing hearing in Texas two decades ago, a defense attorney for a man named Duane Buck called on an expert who said his client's race made it more statistically likely that he would commit violent crimes in the future.Because of that statement, the Supreme Court has ruled 6-2 that Buck, who is black, can appeal his death sentence.It's the latest development in a case that Chief Justice John Roberts describes as "a perfect storm" of circumstances that he says culminated in a lower court "making a decision on life or death on the basis of race."That's from the majority opinion, which Roberts wrote. Justice Clarence Thomas, who was joined by Justice Samuel Alito, wrote the dissenting opinion, in which he stated, "This is an unusual case."Here's how NPR's Nina Totenberg described the case's genesis, in a report after Buck's execution had temporarily been put on hold in 2011: "In 1995, Buck, who is African-American, was convicted of killing two people and shooting a third. During the sentencing phase of his trial, psychologist Walter Quijano was called by the defense. Although Quijano testified that Buck would not pose a continuing threat to society if incarcerated, he also testified that blacks and Hispanics are statistically more likely than whites to commit future crimes. "When the prosecutor cross-examined Quijano, the psychologist testified that being black 'increases the future dangerousness for various complicated reasons.' Buck was ultimately sentenced to death by lethal injection."The question of predicting Buck's behavior was crucial to his sentence: The Supreme Court's summary of the case states that under Texas law, "the jury was permitted to impose a death sentence only if it found unanimously and beyond a reasonable doubt that Buck was likely to commit acts of violence in the future."Today, Roberts wrote, "Dr. Quijano's testimony appealed to a powerful racial stereotype—that of black men as 'violence prone.' "When the case was argued last October, as Nina reported, "Justice Samuel Alito called the introduction of race as a predictor of violence 'indefensible,' but he was also the only justice who voiced skepticism about granting what's called a certificate of appealability for Buck."In pursuing an appeal of his death sentence, Buck has argued that he didn't receive effective legal representation; he also says his case includes extraordinary circumstances that would merit an appeal.From the majority opinion: "Despite knowing Dr. Quijano's view that Buck's race was competent evidence of an increased probability of future violence, defense counsel called Dr. Quijano to the stand and asked him to discuss the 'statistical factors' he had 'looked at in regard to this case.' "Dr. Quijano responded that certain factors were 'know[n] to predict future dangerousness' and, consistent with his report, identified race as one of them. 'It's a sad commentary,' he testified, 'that minorities, Hispanics and black people, are over represented in the Criminal Justice System.' "The jury deliberated for two days before returning a death sentence for Buck. During that time, they asked to see "psychology reports" that had been entered into evidence.Back in 1999, Buck's conviction and sentence were affirmed on direct appeal. But as Roberts wrote, "His case then entered a labyrinth of state and federal collateral review, where it has wandered for the better part of two decades."Quijano gave similar testimony in other cases in Texas — and in 2000, then-Attorney General John Cornyn issued a statement about "problems associated with the testimony" of the psychologist. That was the year the Supreme Court vacated a judgment against Victor Hugo Saldano, whose capital murder trial included testimony from Quijano that Saldano's Hispanic heritage increased the likelihood that he posed a danger.After the court's ruling, Cornyn stated, "It is inappropriate to allow race to be considered as a factor in our criminal justice system."But as the high court noted Wednesday, despite Buck's case being among those Cornyn's office identified as similar to Saldano's, it was not among those in which prosecutors admitted error and allowed new sentencing hearings.Thomas wrote that the lower courts got Buck's case right — and he opened his dissenting opinion with an attack on his colleagues' analysis: "Having settled on a desired outcome, the Court bulldozes procedural obstacles and misapplies settled law to justify it."Part of the problem, in Thomas' view, is that the high court didn't find the lower courts had used the wrong standards to determine their rulings — it's that the majority "simply disagrees with the courts below" in how those standards were applied.Thomas also defended the 5th U.S. Circuit Court of Appeals, saying that his colleagues' criticisms of the appeals court — which the American Bar Association has dubbed "the nation's most divisive, controversial and conservative" — were wrong, misplaced, and misguided."The majority also has things just backwards," Thomas writes.The justice also argued that the jury in the Buck case had sufficient reason to recommend a death sentence aside from the psychologist's consideration of race, saying that the evidence "of both the heinousness of petitioner's crime and his complete lack of remorse was overwhelming."Thomas recounted the crimes Buck is convicted of, saying that despite the defense team's assertion that the murder of Buck's former girlfriend and another man was a crime of passion, the shootings were "premeditated and cruel."Thomas noted that Buck had driven 28 miles to carry out his shooting rampage; that he had also shot his stepsister; that he killed his ex-girlfriend as her children looked on; and that he laughed and joked about the killings afterward.Citing the unique legal circumstances of this case, Thomas also wrote that the court's ruling would likely have only limited legal impact:"Despite its errors, today's opinion should have little effect on the broader law, for two reasons. For one thing, the Court's reasoning is highly factbound, and the facts presented here are unlikely to arise again. For another, although the majority misapplies settled principles, it does not purport to actually alter any of those principles." Copyright 2017 NPR. To see more, visit http://www.npr.org/.