Certificate of Appealability

A certificate of appealability (COA) is a document issued by a court that permits a defendant to appeal a decision in a federal habeas corpus proceeding. Habeas corpus is a legal action that challenges the legality of a defendant’s conviction or sentence based on alleged violations of their constitutional rights. To appeal a denial of habeas relief, the defendant must first obtain a COA from either the district court or the court of appeals. The COA must specify the issues on which the defendant has made a substantial showing of the denial of a constitutional right. This means that reasonable jurists could debate whether the issues should have been resolved differently or that they deserve further proceedings. Without a COA, the defendant cannot pursue an appeal of the habeas decision.