Volume 109, Issue 7

Article

In Defense of Katz: In Memory of Professor Sherry Colb

Erwin Chemerinsky

Dean and Jesse H. Choper Distinguished Professor of Law, University of California, Berkeley School of Law.

11 Feb 2025

Professor Colb addressed issues of privacy and the Fourth Amendment in many of her articles. A key aspect of her scholarship focused on the appropriate test for determining what is a search under the Fourth Amendment. Her article—A World Without Privacy: Why Property Does Not Define the Limits of the Right Against Unreasonable Searches and Seizures—is particularly important now because of a possible shift in the Court away from a focus on privacy in determining what is a search.

In Carpenter v. United States, the Court, in a 5-4 decision, found that the police acquiring a large amount of cellular location information is a search within the meaning of the Fourth Amendment. The Court applied the test from Katz v. United States and found an infringement of the reasonable expectation of privacy. Justice Thomas, in a dissenting opinion, wrote a scathing attack on Katz and called for it to be replaced by a focus solely on whether there is an invasion of property rights. Justice Gorsuch, too, called for use of a property-based approach.

The change in the composition of the Court since then, notably the replacement of Justice Ginsburg (who was in the majority) with Justice Barrett, raises the real possibility that Carpenter would come out differently today. That, in itself, is troubling in terms of protection of privacy from new technology. Even more disturbing is the likelihood that Justice Barrett, like the other originalist Justices, Thomas and Gorsuch, would adopt an approach to the Fourth Amendment that focuses just on whether there is an infringement of property rights.

Building on Professor Colb’s analysis from several of her articles, I argue that the Court’s approach in Katz is desirable and is the proper framework for Fourth Amendment analysis.

The criticism of Katz and the advocacy of a property approach are based on an originalist and formalist approach to the Fourth Amendment that would be highly undesirable.

A focus on the reasonable expectation of privacy, as Professor Colb argued in What is a Search: Two Conceptual Flaws in Fourth Amendment Doctrine and Some Hints of a Remedy, would lead to a more robust Fourth Amendment and provide a desirable resolution of many issues that continue to arise.

To read this Article, please click here: In Defense of Katz: In Memory of Professor Sherry Colb.