In a 6-3 vote, with liberal Justices Sonia Sotomayor, Ketanji Brown Jackson, and Elena Kagan dissenting, the court declined to hear the case of Andre Thomas, thereby upholding his death sentence.
"No jury deciding whether to recommend a death sentence should be tainted by potential racial biases that could infect its deliberation or decision, particularly where the case involved an interracial crime," Sotomayor wrote in her dissenting opinion, per NBC News.
Thomas, now 39, confessed to murdering his estranged wife Laura Boren — a white woman — along with his 4-year-old son and 13-month-old stepdaughter in Sherman, Texas in 2004, claiming he wanted to "set them free from evil."
Thomas, who would later attempt suicide, pleaded not guilty by reason of insanity, but was convicted of his stepdaughter's murder and sentenced to death. However, lawyers for Thomas claimed the sentence should be vacated due to a prejudicial jury.
During the appeal, Thomas' lawyers argued three members of the jury said they were opposed to interracial marriages. Texas prosecutors allegedly used this to their advantage by painting Thomas as a risk to their children.
"Thomas' case undermines principles this Court has repeatedly and forcefully protected: the right to an impartial jury, and the recognition that overt racial bias in the criminal justice system must be eradicated," a lawyer for Thomas wrote.