The Supreme Court of Arkansas struck down a section of its death penalty statute on Thursday, holding that it violated appellant Bruce Ward’s right to due process and equal protection under the US and Arkansas constitutions.

Ward was tried and convicted of capital murder in 1990 and sentenced to death. He was scheduled to be killed by lethal injection in April 2017 but appealed to the state Supreme Court on the grounds that he was not mentally competent to face capital punishment and that the section of the Arkansas code that allowed for the assessment of his mental fitness to be executed was unconstitutional. Ward argued that the Arkansas statute, which was “devoid of any procedure by which a death-row inmate has an opportunity to make an initial substantial threshold showing of insanity,” allowed the Arkansas penal system to execute him unfairly. In a split decision, the Supreme Court agreed with the appellant.

Writing for the majority, Chief Justice John Kemp looked primarily at prior court rulings to evaluate the constitutionality of Arkansas’ mental competency statute. In particular, he cited the US Supreme Court’s decisions in Ford v. Wainwright, establishing that it was unconstitutional to execute a mentally incompetent defendant, and Panetti v. Quarterman, holding that a defendant had a right to a court assessment of their mental capacity following a death penalty conviction, in arriving at his decision. Kemp stated that “the language of section 16-90-506(d)(1)(A) [does not] provide for an evidentiary hearing that comports with the fundamental principles of due process” as established by Ford and Panetti, and the law was therefore unconstitutional.

While the ruling narrowly applies only to insanity defenses for Arkansas’ death penalty, it comes during a period of heavy review of capital punishment in the US. In October Washington state struck down its death penalty, while New Hampshire attempted unsuccessfully to repeal its capital punishment law in June.