Supreme Court to Decide if New Medical Data Can Halt an Execution
Dexter Johnson, convicted of a 2006 murder, argues updated psychiatric guidelines prove he is intellectually disabled, a claim not raised at his original trial.
By Evelyn Henderson ·
The U.S. Supreme Court is set to hear arguments Wednesday on whether a Texas death row inmate can use new medical data to overturn his sentence. The case involves Dexter Johnson, who was convicted of capital murder in connection with the 2006 killing of 23-year-old Maria Aparece.
Johnson’s legal team challenged his death sentence by claiming he is intellectually disabled. This argument was not raised during his initial trial. His scheduled execution in May 2019 was paused after a federal court accepted the new evidence and halted the process.
Ethan Nutter, a lawyer who filed an amicus brief for the National Association of Criminal Defense Lawyers, explained that the medical community’s view of intellectual disability has shifted over the past two decades. Nutter stated that under current standards, Johnson meets the definition of the condition. He noted that the Supreme Court previously ruled it is unconstitutional to execute individuals with this disability.
The defense team filed the claim days before Johnson’s original execution date. They pointed to the 2013 release of the DSM-5, which changed how clinicians evaluate intelligence. The legal filing argued that the DSM-5 replaced a rigid IQ threshold with a focus on adaptive functioning deficits. Under this new framework, a trial expert withdrew a previous objection to a disability diagnosis, and two other experts concluded Johnson is intellectually disabled.
The Texas Department of Criminal Justice asked the Supreme Court to review the Fifth Circuit’s decision in February 2026. The department argued that the lower court’s ruling removed strict limits on claims based on new evidence. In its brief, the agency wrote that for the families of victims, justice delayed is justice denied. Protasio Aparece, the father of the victim, filed his own brief stating his interest in seeing justice carried out for his daughter and avoiding decades of delay.
The justices are deciding a specific procedural question rather than solely addressing Johnson’s individual fate. Nutter described the core issue as whether a federal court can grant a second or successive habeas petition. The court is expected to issue a decision in the case by June 2027.
Source: WXIX-TV
