JULIA SMITH GIBBONS, Circuit Judge. Petitioner-appellant Sidney Cornwell was convicted by an Ohio jury of (1) aggravated murder committed by prior calculation and design; (2) three counts of attempted aggravated murder, with a firearm specification attached to each count and; (3) attached to the aggravated murder count, a death penalty specification that the murder was committed as part of a course of conduct involving the purposeful killing of or attempt to kill two or more people. On direct appeal, the Ohio Supreme Court upheld Cornwell’s conviction and sentence, and the United States Supreme Court denied his petition for a writ of certiorari. After unsuccessfully pursuing postconviction relief in Ohio state court, Cornwell sought a writ of habeas corpus in federal district court. The district court denied Cornwell’s petition but issued a certificate of appealability on three claims. We granted a certificate of appealability on a fourth claim. For the following reasons, we affirm the judgment of the district court denying Cornwell’s habeas petition.