THERE IS NO QUESTION that Duane Buck is responsible for the double murder of his ex-girlfriend and her friend in Houston, Texas, on July 30, 1995.

That morning, Debra Gardner was at home with her two kids and three friends, including Buck’s stepsister, when Buck stormed into the home armed with a shotgun and a rifle. He began shooting: He fired at one of the friends and missed; he shot his stepsister point blank in the chest (she survived); and he fatally wounded another of Gardner’s friends, Kenneth Butler. Gardner fled from the house and Buck followed, killing her in the street as her two children looked on. Buck was arrested at the scene and laughed as he was taken away, according to one law enforcement officer. “The bitch deserved what she got,” Buck allegedly said. In 1997, Buck was tried and convicted of capital murder. He was sentenced to die.

What remains an open question in the case is whether the racially charged testimony of an expert witness tainted Buck’s sentencing hearing, influencing jurors to send him to death row instead of giving him a life term. At specific issue is testimony from psychologist Walter Quijano, who testified that being black made Buck more likely to be violent in the future. That’s no minor assertion given that Texas’s death penalty scheme requires jurors to affirmatively determine that a defendant poses a risk of “future dangerousness” — meaning, a defendant would be prone to commit future acts of violence, including against those inside prison, unless sentenced to die.

It wasn’t the first time that Quijano had expressed this view during a death penalty case. A 2000 review of capital cases by Texas Attorney General John Cornyn (now the senior U.S. senator from Texas) found that Quijano had testified seven times regarding the influence of race on future dangerousness, including in Buck’s case. At the time, Cornyn said that if any of those defendants were to seek a new sentencing hearing the state would not stand in their way because “it is inappropriate to allow race to be considered a factor in our criminal justice system.” And so it went for six of the defendants, all of whom were subsequently re-sentenced to death. (To date, three of them have been executed.) But in the Buck case the state has declined to honor its previous pledge and instead has said that Buck does not deserve a new hearing.

In fact, no court has yet considered the merits of Buck’s claim that the racist testimony impacted his fate. And unless the U.S. Supreme Court steps in — the justices are expected to decide soon whether they’ll take Buck’s case — it is entirely likely that Buck will be put to death without that question ever being answered.

“Mr. Buck received a death sentence that is the product of explicit and blatant racial discrimination,” one of Buck’s attorneys, Kate Black, wrote in an email to The Intercept. “The Supreme Court now has the opportunity to reaffirm the fundamental constitutional principle that racial discrimination has no place in our modern system of justice.”

No court has yet considered the merits of Buck’s claim that the racist testimony impacted his fate.

To the state of Texas, Buck’s case is different from the others featuring Quijano’s conclusions about race and violence because it was Buck’s own defense attorneys who called the psychologist to the stand. That did happen: Buck’s lawyers not only elicited the questionable testimony, but they also introduced into evidence Quijano’s written report, which jurors asked to see during their deliberations, and which far more bluntly made the racist connection. In discussing the “statistical factors” that relate to future dangerousness, Quijano wrote, “Race. Black. Increased possibility. There is an over-representation of Blacks among the violent offenders.”

But it is also true that in cross-examining Quijano, the Harris County prosecutor, Joan Huffman (now a Texas state senator), returned the focus to Buck’s race. “You have determined … that the race factor, black, increases the future dangerousness for various complicated reasons; is that correct?” she asked.

“Yes,” Quijano replied.

Then, in her closing arguments, Huffman encouraged jurors to rely on Quijano’s expertise, reminding them that he’d said that there was a “probability that [Buck] would commit future acts of violence.”

And despite the state’s assertion that somehow Buck’s case is inherently different from the others in which Quijano testified, it turns out that in two of those cases the psychologist was also called to the stand by the defense.

To date, the only real consideration given by the courts to the question of what impact the racially biased conclusion had on Buck’s sentence has centered around the issue of who is responsible for its inclusion at the hearing. That, according to Buck’s current attorneys, is due to deficient lawyering — by Buck’s attorneys both at trial and on appeal. Introducing the testimony and expert report at trial was certainly a dubious decision (as was the failure to object to the prosecutor’s focus on race in Quijano’s cross-examination). But perhaps even more damaging to Buck’s current situation was the failure of his subsequent attorney to argue on appeal that the trial lawyers provided constitutionally ineffective assistance to Buck during the sentencing hearing by offering the jurors Quijano’s conclusions.

In fact, it wasn’t until two years after Cornyn admitted that Quijano’s testimony was problematic — and more than five years after Buck’s initial appeal was filed — that the appellate lawyer raised the issue. But by that time it was too late: Failing to make that argument in Buck’s first appeal meant that he had forfeited the ability to do so at all. There is good evidence that the jurors in Buck’s case were influenced by the racist assertion, because in the third of three notes sent to the court during their deliberations the jurors specifically asked to review Quijano’s expert report. Procedurally, however, there was no way for the courts to consider whether those deficiencies meant Buck should be granted a new hearing, free from discriminatory testimony and conclusions.

Nonetheless, judges who have refused to consider the merits of Buck’s claims have noted that the testimony itself is troubling. In 2011, for example, Supreme Court Justice Samuel Alito opined that the testimony was “bizarre and objectionable.” Even so, he wrote that it was the defense’s fault for eliciting that testimony in the first place.

By 2013, the Supreme Court had decided a pair of cases that effectively tweaked the law to provide some ability for defendants to revisit defaulted claims of ineffective lawyering — but only in “extraordinary” cases. Since then the discussion around Buck’s case has become exhaustingly focused on whether the underlying circumstances are exceptional enough for the appeal to be considered. So far the courts have ruled that they are not. Indeed, a federal district judge in Houston wrote in 2014 that Buck’s trial counsel was in fact constitutionally deficient — he “recklessly exposed his client to the risks of racial prejudice and introduced testimony that was contrary to his client’s interests” — but concluded that while “the introduction of any mention of race was ill-advised at best and repugnant at worst, it was, in this case, de minimis” and thus not eligible for further consideration.

Harris County prosecutors were more than three times as likely to seek the death penalty against black defendants.

Of course, it is impossible for that judge — or, really, at this point, any judge — to know how damaging the improper testimony was without granting Buck’s appeal. But given the pervasiveness of racism within the criminal justice system as a whole, and within the death penalty system in particular, there’s ample reason to believe that Buck’s race had more than a passing impact on his fate. For example, a 2012 study found that over a seven-year period that included the year Buck was tried, prosecutors in Harris County were more than three times as likely to seek the death penalty against black defendants than against white defendants, and juries were more than twice as likely to sentence black defendants to death. The numbers don’t appear to have improved: Since 2004, even as the number of new death sentences has declined steeply, the county has sent 15 new prisoners to death row — all of them minorities.

The Houston numbers are similar to those found in other death penalty states. A California study found that defendants who killed a white person were three times more likely to be put to death than those who killed a black person, for example, while a study in Washington state found that jurors are three times more likely to sentence a black person to death than they are a white person. Indeed, 43 percent of death row inmates are black, even though black people make up just about 13 percent of the U.S. population.

Still, raw numbers have not generally impressed the judiciary — including the Supreme Court, which opined in a seminal and troubling 1987 case known as McCleskey v. Kemp that aggregated numbers demonstrating systemic racism simply couldn’t prove that racism impacted any single, specific case. That conclusion still informs jurists confronted with questions about the impact of racism in the criminal justice system today, and, as the NAACP’s Legal Defense Fund describes it, the decision has actually formed a “substantial barrier to the elimination of racial inequalities in the criminal justice system, perpetuating an unfair racial imbalance that has come to define criminal justice in America.”

Even when case-specific racism has been demonstrated, the courts have declined to act. Consider the case of Kenneth Fults, executed April 12 by the state of Georgia after the Supreme Court, without comment, declined to intervene — even in the face of direct evidence that one of the jurors in his case had decided to vote to send him to death simply because he was black. “I don’t know if [Fults] ever killed anybody, but that nigger got just what should have happened,” the juror, Thomas Buffington, admitted in a 2005 affidavit. “Once he pled guilty, I knew I would vote for the death penalty because that’s what that nigger deserved.”

It’s unclear why the judiciary seems so reluctant to wade directly into the morass of racial bias in criminal cases. It could be that acknowledging the problem would strengthen the argument that the death penalty is a cruel and unusual punishment. Or perhaps members of the judiciary share some of the racist notions that infected Buck’s case. There is some support for the latter proposition, at least within the 5th U.S. Circuit Court of Appeals, a venue notoriously unfriendly to criminal defendants — and the same court that has repeatedly denied Buck’s appeals. Indeed, in June 2013 several advocacy groups filed a complaint against that court’s chief judge, Edith Jones, who said that February during a lecture on the death penalty at the University of Pennsylvania School of Law that the issue of racism in the context of the death penalty is a “red herring” and that blacks and Hispanics are more likely to commit crime. When asked to explain her comments, according to the complaint, Jones “stated that there was ‘no arguing’ that ‘Blacks and Hispanics’ outnumber ‘Anglos’ on death row and ‘sadly’ it was a ‘statistical fact’ that people ‘from these racial groups get involved in more violent crime.’”

The grievance was eventually dismissed by the judge’s peers.