United States v. Mezzanatto

Summary

The Court, in an opinion by Justice Thomas, held that a criminal defendant may knowingly and voluntarily waive the protections of Federal Rule of Evidence 410 and Federal Rule of Criminal Procedure 11(e)(6) to permit impeachment with statements made during plea discussions. It reversed the Ninth Circuit’s categorical rejection of such waivers. The Court applied the background presumption that statutory and evidentiary protections are waivable and found no contrary congressional intent or sufficient policy basis for prohibiting waiver. Justice Ginsburg, joined by Justices O’Connor and Breyer, concurred, emphasizing that the Court did not decide whether a waiver permitting use in the prosecution’s case in chief would be enforceable. Justice Souter, joined by Justice Stevens, dissented, concluding that Congress intended nonwaivable protection to encourage candid plea discussions and warning that routine waiver demands would effectively nullify the Rules.