Document Type


Publication Date



A detailed analysis of the common law during the Framers’ era, and of how it reflected the Fourth Amendment’s restrictions, shows that many judges believed they could issue search warrants without independently assessing the adequacy of probable cause, and that this view persisted even after the Fourth Amendment became effective. This conclusion challenges the leading originalist account of the Fourth Amendment, which Professor Thomas Davies published in the Michigan Law Review in 1999.

Learned treatises in particular, and to a lesser extent a few case decisions, had articulated a judicial duty to monitor probable cause. But it is a mistake to presume that the law was necessarily implemented in accordance with this elite guidance. This is because justices of the peace, the non-elite judges who actually issued search warrants, had reason to believe that judicial sentryship of probable cause was often optional. Evidence supporting this conclusion can be found in treatises, manuals for justices of the peace, legal forms, civil search statutes, and case law, as well as in the extended development of probable cause sentryship jurisprudence, which continued well past 1960. American justice of the peace manuals and legal forms play a particularly important role in this story, as it is likely they had a profound influence on search warrant procedure given the laxity in legal education and judicial training, as well as the limitations on legal research, during the Framers’ era.

This article challenges our current understanding of the Fourth Amendment, including the relationship between its Reasonableness and Warrant clauses, raises questions about originalism, and contributes to our understanding of the sources and methods used by judges during the Framers’ era, as well as by historians today. These topics will continue to be explored in a future article, which will focus in much greater detail upon statutory law from the Framers’ era.