Tommy Arthur (pictured), an Alabama death-row prisoner whose 35-year journey through the court system has frustrated both proponents and opponents of the death penalty, is scheduled to be executed on May 25, 2017, the eighth time Alabama has set an execution date in his case.

Arthur—whose conviction and death sentence has twice been overturned by the courts and was sentenced to death by his trial judge based upon a non-unanimous jury sentencing recommendation—has steadfastly maintained his innocence in the 1982 murder of Troy Wicker. Most recently, an evenly divided U.S. Supreme Court issued a stay of execution four hours after Arthur’s execution was set to begin on November 3, 2016, so the Court could consider whether to review Arthur’s challenge to Alabama’s use of the controversial drug midazolam and his request to be executed by firing squad. The Court ultimately declined to review both that claim and Arthur’s separate challenge to the constitutionality of Alabama’s non-unanimous sentencing practices.

Arthur has repeatedly raised innocence claims, seeking new forensic testing of evidence from his case. Judy Wicker, the wife of Troy Wicker, who was charged with hiring Arthur to kill her husband, testified at her trial that her husband had been murdered by a burglar who beat and raped her. After Ms. Wicker’s conviction, she changed her testimony when a prosecutor, who had previously represented her at a parole hearing, offered her early release if she testified against Arthur.

The rape kit taken from Ms. Wicker at the time of the murder was lost or destroyed without being tested for DNA and, according to Arthur’s current lawyer, Suhana Han, “[n]either a fingerprint or a weapon, nor any other physical evidence connects Arthur to the murder of Troy Wicker.” Hairs found near the victim have also never been tested with modern DNA technology.

Arthur has also argued that his trial counsel was ineffective, and continues to litigate issues relating to Alabama’s lethal injection protocol. He currently has an emergency motion pending before the U.S. Court of Appeals for the 11th Circuit, challenging the state’s planned use of midazolam, a drug that has been linked to many problematic executions, including that of Ron Smith in Alabama in December 2016. He has also challenged the state’s refusal to disclose records related to the Smith execution, which his lawyers say may provide critical evidence for his lethal-injection challenge.

The Alabama Court of Criminal Appeals issued a preliminary ruling in Arthur’s favor on a separate issue on May 23, reversing a Montgomery Circuit judge’s order rejecting Arthur’s claim that the legislature, rather than the Department of Corrections, should determine the state’s execution method. But that procedural ruling will not delay his execution. His motion stated, “The role of the legislature is particularly critical given the controversial nature of the ADOC’s current midazolam-based execution protocol. …The choice of the first drug (midazolam) to be used is critical, because without an effective anesthetic, the second and third drugs would cause unbearable pain. But the drug the ADOC chose (in secret), midazolam, is not used in medical practice as a general anesthetic; rather, it is an anti-anxiety sedative in the same drug family as Valium and Xanax, and its use in lethal injection has been extremely problematic.”

[UPDATE: Alabama executed Thomas Arthur near midnight on May 25. He was pronounced dead at 12:15 a.m. on May 26. Media witnesses reported no visible indicators that the drugs had failed.]