The Fourth Amendment requires that warrants be supported by “Oath or affirmation.” Under current doctrine, a police officer may swear the oath to obtain a warrant merely by repeating the account of an informant. This Article shows, however, that the Fourth Amendment, as originally understood, required that the real accuser with personal knowledge swear the oath.

That real-accuser requirement persisted for nearly two centuries. Almost all federal courts and most state courts from 1850 to 1960 held that the oath, by its very nature, required a witness with personal knowledge. Only in 1960 did the Supreme Court hold in Jones v. United States that a warrant could rely upon hearsay. Jones radically altered criminal investigations. But the decision rested entirely on policy preferences, ignoring text, original meaning, and rich contrary precedent.

This Article argues that we should return to the original understanding that the oath requirement bans thirdhand accounts. Remarkably, this is the first comprehensive study to consider whether the oath requires personal knowledge.

* Professor of Law, University of Arkansas School of Law, Fayetteville. The Author would like to thank William Baude, Ric Simmons, Richard D. Friedman, Jeffrey Bellin, Thomas Y. Davies, Susan N. Herman, Michael J. Zydney Mannheimer, Jordan Blair Woods, Orin S. Kerr, G. Alex Nunn, Wesley M. Oliver, George C. Thomas III, Daniel Bell, Sarah King-Mayes, Elizabeth Kiszonas, and Mimi Jacobs.