Although a criminal defendant has no express constitutional right to discovery, both the U.S. Supreme Court and the U.S. Congress have specified rights to disclosure for criminal defendants. In Brady v. Maryland, the U.S. Supreme Court recognized that access to certain specific information is essential to a defendant's right to due process and a fair trial. Other constitutional requirements of discovery pertain to materiality, specificity of discovery request, the scope of the Brady duty, impeachment evidence, the creation and preservation of evidence, and privileged or inaccessible information. The Jencks Act and Federal Rule of Criminal Procedure 26.2 (Rule 26.2) grant litigants in Federal criminal proceedings a general right to discover a witness' prior statements that may be useful for impeachment purposes. After indictment, a Federal defendant may conduct discovery under Rule 16. Under Rule 17, the use of subpoenas is available to both the defendant and the government. Federal Rule of Evidence 404(b) requires that the prosecution notify the defense before trial of its intention to introduce any evidence of the defendant's prior bad acts. 242 footnotes