Duane Buck has been challenging his death sentence for nearly 14 years, saying it was based partly on racial prejudice after a psychologist testified the convicted murderer was more likely to be a danger because he is black.
On Wednesday, the U.S. Supreme Court takes up his latest appeal.
"This stereotype, that black men are more dangerous, is animating our entire public discussion these days. It's now up to this court to say, 'That's enough,'" said Kathryn Kase of the Texas Defender Service.
A few weeks after breaking up with his girlfriend in 1995, Buck barged into her Texas home with a shotgun and a rifle. He wounded his stepsister, killed another man who was in the house, then followed his former girlfriend outside and killed her in front of her children.
At the sentencing hearing, Buck's own lawyers called a former prison psychiatrist, Walter Quijano, to assess his future dangerousness. He would be unlikely to be violent in the future, Quijano said, but Buck's race "increased the probability" of future violence.
"It's a sad commentary that minorities — Hispanics and black people — are over-represented in the criminal justice system," he said.
Future dangerousness is one of the factors a Texas jury must unanimously find before a defendant can be sentenced to death.
In the first of what would become several unsuccessful appeals, newly appointed counsel failed to challenge the decision by Buck's own trial lawyers to introduce the psychiatrist's testimony.
But in 2000, the Texas attorney general said a defendant's race should never be an issue at sentencing and identified Buck's case as one in which the state would not oppose an appeal for a new sentencing hearing. The state later reversed course, explaining that because it was Buck's own lawyers who raised the issue, the state had not made an error that needed to be remedied.
Last August, a federal appeals court declined to give Buck permission to pursue his appeals.
"As a result, a death sentence tainted by egregious racial bias remains intact, and the legitimacy of our criminal justice system has been seriously undermined," said Sherrilyn Ifill of the NAACP legal defense fund, which is representing Buck before the Supreme Court.
Lawyers for the state downplayed the significance of the psychiatrist's testimony, which said Buck presented a low likelihood of future dangerousness.
They also argued that Buck cannot show a "substantial likelihood" that a jury would have reached a different conclusion without the discredited testimony about race, which the state says is a precondition for a new round of appeals. Evidence of his future dangerousness, including "the horrific facts of the offense" and Buck's lack of remorse, was overwhelming, they said.
But Kase said the Supreme Court should send a clear message that appeals to racial prejudice have no place in the criminal justice system.
A decision is expected sometime before late June