The Supreme Court blocked Alabama’s attempt to execute a convicted murderer Thursday, ruling 5-4 that Joseph Clifton Smith’s intellectual disability makes execution unconstitutional under the Eighth Amendment’s prohibition of cruel and unusual punishment.

Court Divides Over IQ Score Standards

The justices left unresolved the central question of how courts should evaluate conflicting intelligence test results when determining intellectual disability. Smith recorded five IQ scores over nearly 40 years, ranging from 72 to 78. Medical groups consider scores below 70 as indicating intellectual disability, though they emphasize that testing margins of error and holistic assessments of social and practical skills should factor into determinations rather than numbers alone.

Justice Sonia Sotomayor, joined by Justice Ketanji Brown Jackson, argued the Court lacks sufficient grounds to establish broad standards in this case. She recommended courts continue case-by-case evaluations using legal precedent and medical expert guidance. Four conservative justices dissented, with Justice Samuel Alito criticizing the majority for avoiding its responsibility to provide clear rules for capital cases.

Alabama Challenged Disability Finding

Alabama officials argued Smith does not meet the threshold for intellectual disability because none of his IQ scores fell at or below 70. The state contended it maintains discretion in weighing multiple test scores and that the Eighth Amendment does not override the death sentence Smith received for murdering Durk Van Dam during a 1997 robbery. Two lower federal courts disagreed, determining that Smith’s test scores, combined with his school records showing he functioned two grade levels behind placement and received special education classification, proved disability status.

Broader Death Penalty Implications

The Supreme Court banned executing intellectually disabled individuals in capital crimes over 20 years ago. Approximately 420 of the 2,100 people currently on death row may have some degree of intellectual disability, according to the Death Penalty Information Center. Smith will now serve life imprisonment. Justice Clarence Thomas wrote separately calling for reinstatement of death penalty eligibility for intellectually disabled defendants, highlighting ongoing disagreement over constitutional protections in capital punishment.