The Florida Rules of Criminal Procedure required a criminal defendant to give pretrial notice to the prosecution if he planned on raising an alibi defense at trial, including information about the place the defendant claimed to have been and the names and addresses of any alibi witnesses the defendant intended to call at trial. In advance of his robbery trial, Williams (defendant) moved for a protective order to be excused from the rule's requirements, arguing that the rule violated his Fifth and Fourteenth Amendment rights by compelling him to be a witness against himself. However, Williams ultimately complied with the rule after his motion was denied. Williams also filed a pretrial motion for a 12-person jury instead of the six-person jury provided by Florida law in noncapital cases; this motion was denied. Williams identified Mary Scotty as his alibi witness. Prosecutors called Scotty for a pretrial deposition. Scotty then testified at trial that Williams was at her apartment during the time of the robbery. The prosecution impeached Scotty twice during cross-examination with her deposition testimony. The state also presented the rebuttal testimony of an officer who said that Scotty had asked him for directions during the time in which she claimed to be in her apartment with Williams. The jury ultimately convicted WIlliams, and he was sentenced to life in prison. The appellate court affirmed the conviction. The United States Supreme Court granted certiorari.