Supreme Court to Decide Standards for New Evidence in Death Penalty Cases

The U.S. Supreme Court will hear arguments on Wednesday regarding the procedural standards federal courts must apply when prisoners file new challenges to their sentences. The case centers on Dexter Johnson, a Texas death row inmate, and whether his intellectual disability claim qualifies for review despite being raised late in the legal process. The decision will establish a precedent for how strictly appellate courts handle successive habeas petitions in capital cases.

Johnson was convicted of capital murder in 2006 for the killing of 23-year-old Maria Aparece. His execution was originally scheduled for May 2019. A federal court stayed that date after his legal team challenged the sentence based on intellectual disability. This argument was not presented during his initial trial. The stay remains in effect while the Supreme Court reviews the matter.

The legal dispute arose from changes in medical guidelines. In 2013, the American Psychiatric Association updated the Diagnostic and Statistical Manual of Mental Disorders to the Fifth Edition, or DSM-5. This update shifted the diagnostic focus from rigid IQ thresholds to adaptive functioning deficits. Johnson's attorneys argued that under this new framework, two experts concluded he is intellectually disabled, while his trial expert withdrew the previous assessment that had blocked the diagnosis.

Ethan Nutter, a lawyer who filed an amicus brief on behalf of the National Association of Criminal Defense Lawyers, stated that the medical community's understanding of the condition has shifted over the last two decades. He noted that the Supreme Court has previously ruled it unconstitutional to execute individuals with intellectual disabilities. Nutter clarified that the court is deciding a specific procedural issue regarding whether federal courts can address a second or successive habeas petition.

The Texas Department of Criminal Justice asked the Supreme Court to review the Fifth Circuit Court of Appeals' decision in February 2026. The department argued in its brief that the lower court's ruling erases strict limits on claims based on new evidence. It further stated that for the people of Texas and the families of victims, justice delayed is justice denied.

Protasio Aparece, the father of the victim, filed his own amicus brief. His legal team wrote that Protasio has an interest in seeing justice carried out for his daughter. They added that he wants to ensure no other family endures the excessive delays that his family has suffered.

The Supreme Court is expected to issue a final decision in this case by June 2027. The ruling will determine how federal courts process new evidence in pending death penalty cases.