The petitioner in this case was sentenced to death in the Alabama state courts. He then sought habeas corpus relief in federal court. The ACLU amicus brief focuses on the standard that applies when federal habeas courts review state court factual findings and, more specifically, on the interplay between two related provisions of federal habeas law. In this case, we argue, the federal court of appeals applied the wrong standard in assessing the reasonableness of the state court’s factual findings and therefore erred in upholding the challenged death sentence.