Poyson v. Ryan, 743 F.3d 1185

Poyson was convicted of three counts of first-degree murder and sentenced to death in 1998 in Arizona.
Arizona Supreme Court affirmed the conviction and sentence on direct appeal after independent review.
Poyson raised three federal habeas claims certified for review: unconstitutional causal nexus to mitigating evidence, failure to consider substance abuse as mitigation, and penalty-phase ineffective assistance of counsel.
The district court denied relief; the Ninth Circuit affirmed the district court’s denial as to the arguments presented.
The panel majority denied habeas relief on the causal nexus issue due to an insolubly ambiguous record; certain arguments were deemed procedurally defaulted or unexhausted.
The opinion discusses the applicable Eighth Amendment standards (Lockett, Eddings, Penry) and the nexus approach historically used by Arizona courts.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Arizona's causal nexus test violated Eighth/Fourteenth Amendments.	Poyson contends the Arizona Supreme Court applied an unconstitutional causal nexus to mitigate evidence.	Arizona courts considered mitigating evidence and weighed it; there was no clear constitutional violation.	Not clearly violated given the record; ambiguity prevents relief.
Whether the state courts' treatment of substance abuse as nonmitigating violated Lockett/Eddings.	Poyson argues substance abuse evidence was improperly disregarded.	State courts considered but found lack of substantial substance abuse and no causal link.	No constitutional violation; evidence considered but not found mitigating.
Whether Poyson’s penalty-phase ineffective assistance claim is defaulted procedurally.	Federal claim mirrors state claim; new theory may not be allowed if it alters the claim.	New factual theory was not fairly presented; default applies.	Procedurally defaulted in district court; affirm.
Whether exhaustion and AEDPA standards were properly applied to the causal nexus claim.	Exhaustion satisfied; claim fully presented to state courts.	Ambiguity and standards under AEDPA unresolved; defer to state court.	Exhausted; AEDPA standard applied; relief denied on the causal nexus theory.

Tennard v. Dretke, 542 U.S. 274 (U.S. 2004) (holding that requiring causal connections in mitigation is unconstitutional)
Eddings v. Oklahoma, 455 U.S. 104 (U.S. 1982) (sentencer must consider relevant mitigating evidence)
Lopez v. Ryan, 630 F.3d 1198 (9th Cir. 2011) (court may weigh mitigating evidence; not require causal nexus)
Schad v. Ryan, 671 F.3d 708 (9th Cir. 2011) (ambiguous records preclude relief unless clear error shown)
Towery v. Ryan, 673 F.3d 933 (9th Cir. 2012) (causal nexus used as a weighting factor, not a screening rule)