(CN) – The Ninth Circuit on Friday overturned the death sentence of a man convicted of a triple-murder in Arizona, finding the state’s Supreme Court treated mitigating evidence of his troubled childhood and mental health as irrelevant.
Poyson was convicted and sentenced to death in 1998 for the killings of three people in northwestern Arizona.
In 1996, Poyson was 19 and homeless when he was invited by Leta Kagen to stay in her trailer with her boyfriend, Ronald Wear, and her teenage son, Robert Delahunt, near Kingman, Arizona.
Kagen later invited two others, Frank Anderson and Kimberly Lane, to stay in the trailer.
According to court documents, the three guests then formulated a plan to kill her, Wear and Delahunt.
On Aug. 13, 1996, Anderson slit Delahunt’s neck, while Poyson shoved a bread knife through the 15-year-old’s ear and bashed his head against the trailer floor.
Poyson then shot Kagen in the head and Wear through the mouth, before beating Wear’s head with a rifle and a cinderblock.
Poyson, Anderson and Lane were later apprehended in Illinois in Wear’s truck.
In the amended opinion, a three-judge panel granted Poyson’s petition for a rehearing and reversed a federal court’s denial of his habeas corpus challenge to his death sentence.
The panel found Poyson’s Eighth Amendment right to individualized sentencing was denied by the Arizona Supreme Court when it applied an unconstitutional “causal nexus” test to mitigating evidence of his mental health and troubled childhood.
Poyson presented evidence that both of his parents had abused drugs and alcohol, including while his mother was pregnant with him.
He never had a stable father-figure in his life as his mother dated a number of men, he said, including one who did time in jail for hitting Poyson with an electrical cord and one who drank and did drugs with him.
Later, after a period of stability Poyson’s stepfather committed suicide and Poyson was later sodomized by a neighbor.
“(A) state court may not treat mitigating evidence of a defendant’s background or character as ‘irrelevant or nonmitigating as a matter of law’ merely because it lacks a causal connection to the crime,” wrote Circuit Judge Raymond Fisher on behalf of the panel.
In 2015’s McKinney v. Ryan, the appeals court found that from the late 1980s to the mid-2000s, the Arizona Supreme Court routinely used this unconstitutional test when considering mitigating evidence.
“[A]s a matter of law, a difficult family background or mental condition did not qualify as a nonstatutory mitigating factor unless it had a causal effect on the defendant’s behavior in committing the crime at issue,” the McKinney court held.
The panel remands its decision to federal court, with instructions to grant the writ of habeas corpus with respect to Poyson’s sentence “unless the state, within a reasonable period, either corrects the constitutional error in his death sentence or vacates the sentence and imposes a lesser sentence consistent with law.”
The panel denied Poyson’s contention that he was entitled to a new sentencing proceeding for the court’s failure to consider his alleged substance abuse, however.
“Even assuming that the state courts’ determination that Poyson provided only ‘vague allegations’ of substance abuse was an unreasonable determination of the facts … Poyson’s claim fails because he cannot demonstrate his constitutional rights were violated,” Fisher wrote.
Circuit Judge Sandra Ikuta “reluctantly” issued a concurrence with the panel’s decision, finding it was bound by McKinney until overruled by a future en banc panel.
“(McKinney) held that we must presume the Arizona Supreme Court applied the unconstitutional causal nexus test between 1989 and 2005, even when, as here, the court expressly discussed the weight of the evidence,” Ikuta wrote.
Chief Circuit Judge Sidney Thomas also sat on the panel.
Poyson’s public defender and the Arizona Attorney General’s Office did not respond to requests for comment before publication.