The Private-Search Doctrine Does Not Exist

60 Pages Posted: 10 Dec 2019 Last revised: 27 Jan 2021

See all articles by Ben A. McJunkin

Ben A. McJunkin

Arizona State University (ASU) - Sandra Day O'Connor College of Law

Date Written: November 15, 2018


This Article advances the novel argument that there is no such thing as the Fourth Amendment’s private-search doctrine. For nearly four decades, courts have invoked the doctrine to permit police to replicate, without a warrant, a prior search performed by a private third party. This Article contends that the doctrine rests on a fundamental misreading of the Supreme Court’s seminal precedents and an untenable theory of Fourth Amendment privacy.

The Supreme Court has never announced a “private-search doctrine.” It has addressed the fact pattern of private searches only twice, and not since 1984. The opinions in those two cases, Walter v. United States and United States v. Jacobsen, are notoriously unsettling and hard to judge. Yet courts and commentators have long interpreted those cases as holding that Fourth Amendment privacy is vitiated by the exposure of information to third parties, even when that exposure is the result of an unforeseeable and surreptitious search. Uncertainty over the bounds of the doctrine has resulted in the development of drastically different approaches to private searches, recently culminating in a federal circuit split.

Performing a close examination of the Walter and Jacobsen opinions, this Article demonstrates that those cases are best understood not as announcing a new Fourth Amendment doctrine—the private-search doctrine—but rather as extending an existing exception—the single-purpose container doctrine—into a new factual context. Correcting this decades-old mistake harmonizes many of the intuitions of lower courts regarding private searches while simultaneously resolving two circuit splits: the split over the private-search doctrine and a longstanding split over the application of the single-purpose container doctrine. Perhaps more importantly, this correction also sheds new light on the nature of Fourth Amendment privacy and the normative arguments for its protection.

Keywords: criminal procedure, search & seizure, Fourth Amendment, privacy, private search

Suggested Citation

McJunkin, Ben A., The Private-Search Doctrine Does Not Exist (November 15, 2018). 2018 Wisconsin Law Review 971 (2018), Available at SSRN:

Ben A. McJunkin (Contact Author)

Arizona State University (ASU) - Sandra Day O'Connor College of Law ( email )

Box 877906
Tempe, AZ 85287-7906
United States

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