Supreme Court to rule on how IQ scores are weighed in death penalty disability claims

The Supreme Court will clarify how IQ scores should be evaluated when a death sentence is barred based on an intellectual disability.

The court already ruled in 2002, in Atkins v. Virginia, that executing people with intellectual disabilities violated the Constitution’s Eighth Amendment, which prohibits “cruel and unusual punishment,” but justices did not define intellectual disability.

In Hamm v. Smith, the court will consider whether Joseph Smith, facing execution in Alabama for the 1998 murder of Durk Van Dam, should be spared because his IQ test scores hover so closely to the threshold of 70 established in the Atkins case. Smith was given several IQ tests ranging from 72 to 78, above the standard threshold of 70, but within the margin of error.

“As long as the death penalty remains on the books in this country, it is essential that these guardrails are upheld to safeguard the most vulnerable among us, including those with intellectual disabilities,” said Krisanne Vaillancourt Murphy, executive director of the Catholic Mobilizing Network, an anti-death penalty group based in Washington, D.C. “The surest way to protect the sanctity of life in these instances is to end the practice of capital punishment altogether.”

In 2018, Pope Francis updated paragraph 2267 of the Catechism of the Catholic Church, declaring the death penalty “inadmissible” because “it is an attack on the inviolability and dignity of the person.” Pope Leo XIV affirmed this, saying that those who are against abortion must also be against capital punishment as they both degrade human life.

Vaillancourt Murphy said the death penalty is more unpopular than ever, mostly because of “young adults who, by and large, oppose the death penalty far more than their older counterparts.”

Oral arguments in the case were heard in December 2025. Eighteen states and the Trump administration filed briefs supporting Alabama.

Assistant to the U.S. Solicitor General Harry Graver told the justices that the court’s ruling in Atkins had “outsourced the definition of intellectual ability to the states,” giving them “significant discretion in defining what it means to be intellectually disabled and what a defendant must do to prove it.”

Theresa Farnan, a philosopher on the Ethics and Public Policy Committee of the National Catholic Partnership on Disability, said several conditions should be evaluated to determine an inmate’s intellectual ability outside of IQ tests, including their social adaptability and early childhood performance.

“This was clearly a borderline case,” Farnan said, noting that Smith could not finish grade school, struggled with reading, and could not keep jobs created for special needs employees. “It’s obvious to me he could not grasp the gravity of his crimes. In cases like these, the burden on us as a society is even more pronounced to be radically pro-life.”

She said the court may establish a legal precedent in this case in which these holistic evaluations will be used by states in assessing intellectual fitness.

The American Psychological Association with the American Psychiatric Association and the Alabama Psychological Association argued in their amicus briefs that diagnosing intellectual disability requires a comprehensive clinical assessment that goes beyond just IQ test scores. Their briefs clarified that IQ tests are not always definitive.

A decision is expected by July.