The U.S. Supreme Court is scheduled to hear a case Wednesday centering on a dispute over a Texas death row inmate's sentence.

It came before the justices after the legal team for the inmate, Dexter Johnson, challenged his death sentence, under a claim of intellectual disability.

And it was a claim that not brought up during his initial trial."What's happened here is that in the last 10 to 20 years, the medical community's understanding of intellectual disability has changed," said Ethan Nutter, a lawyer who filed an amicus brief in the case, on behalf of the National Association of Criminal Defense Lawyers.