Poyson v. Ryan

Habeas corpus relief will not be granted when, during sentencing, the court utilizes a causal nexus test to mitigating factors in order to determine the weight of the evidence and the record does not show whether the court considered the absence of a causal nexus as a “permissible weighing mechanism” or as an “unconstitutional screening mechanism.”

In 1998, Robert Allen Poyson was convicted of murder and sentenced to death. He sought post-conviction relief in Arizona state court and then filed a habeas petition in federal district court. The court denied the petition, and Poyson appealed. The Ninth Circuit held that Poyson’s first claim on appeal, that the state courts applied an “unconstitutional causal nexus test to mitigating evidence,” was without merit because the panel could not determine from the ambiguous record whether the court actually applied an unconstitutional test or instead made a permissible determination of the weight of the mitigating evidence. The panel held Poyson’s second claim, that the state court “failed to consider mitigating evidence of his history of substance abuse,” was also without merit because the state court correctly found that the evidence presented failed to prove Poyson’s history of substance abuse. Finally, the panel held that Poyson’s third claim, that his trial counsel provided ineffective assistance, was procedurally defaulted because it was “fundamentally different from the claim presented in state court.” AFFIRMED.