Wardius v. Oregon, 412 U.S. 470 (1973)

The U.S. Supreme Court held the Due Process Clause of the 14th Amendment did not require an accused person to give pretrial notice to the prosecution of his alibi defense and witnesses unless the accused person had reciprocal discovery rights. The conviction was reversed and remanded. To support this ruling, the Court stated:  

“Although the Due Process Clause has little to say regarding the amount of discovery which the parties must be afforded, but cf. Brady v. Maryland, 373 U.S. 83 (1963), it does speak to the balance of forces between the accused and his accuser. Cf. In re Winship, 397 U.S. 358, 361-364 (1970).
[W]e do hold that in the absence of a strong showing of state interests to the contrary, discovery must be a two-way street. The State may not insist that trials be run as a “search for truth” so far as defense witnesses are concerned, while maintaining “poker game” secrecy for its own witnesses. It is fundamentally unfair to require a defendant to divulge the details of his own case while at the same time subjecting him to the hazard of surprise concerning refutation of the very pieces of evidence which he disclosed to the State.”