Michael Mendenhall v. City and County of Denver, Colorado

The Fourth Amendment provides that “no Warrants shall issue, but upon probable cause, supported by Oath or affirmation.” U.S. Const. amend. IV. “Oath or affirmation,” as originally understood, required a witness with firsthand knowledge of the facts to swear an oath before the issuing magistrate. Without ever addressing the oath requirement in its legal analysis, this Court in Jones v. United States, 362 U.S. 257 (1960), held that hearsay can satisfy the Warrant Clause. Jones abandoned the categorical guarantee the Founders embedded in the Fourth Amendment and set the Court on a course toward open-ended balancing, ignoring the constitutional text, its original meaning, and a century and a half of contrary precedent. The question presented is: Whether this Court should overrule Jones and hold that the Fourth Amendment requires a witness with firsthand knowledge to swear an oath before a warrant can issue.