Morrison (defendant) was convicted of rape. He appealed on the grounds that his attorney’s assistance was constitutionally ineffective. Specifically, Morrison stated that his attorney failed to exclude from evidence an inculpating bed sheet that was the product of a violation of Morrison’s Fourth Amendment rights. In response, the state claimed that because Fourth Amendment exclusionary rule claims are not cognizable in federal habeas proceedings under Stone v. Powell, 428 U.S. 465 (1976), Morrison’s claim of ineffective assistance of counsel was not cognizable either because it was based on the attorney’s failure to utilize the exclusionary rule. The United States Supreme Court granted certiorari.