«AN EQUILIBRIUM-ADJUSTMENT THEORY OF THE FOURTH AMENDMENT Orin S. Kerr CONTENTS INTRODUCTION I. THE THEORY OF EQUILIBRIUM-ADJUSTMENT IN FOURTH ...»
AN EQUILIBRIUM-ADJUSTMENT THEORY
OF THE FOURTH AMENDMENT
Orin S. Kerr
I. THE THEORY OF EQUILIBRIUM-ADJUSTMENT IN FOURTH AMENDMENT
A. The Fourth Amendment in Year Zero
B. How New Facts Threaten the Balance of Power
C. The Theory of Equilibrium-Adjustment and Six Scenarios
1. The Government Uses a New Tool to Find Evidence.
2. Criminals Use a New Tool to Evade Detection.
3. New Crimes and New Practices
4. Both Criminals and the Police Use a New Tool
5. The Status Quo
6. Defeating Countermeasures
D. Equilibrium-Adjustment and Fourth Amendment Doctrine, at Both the Principles Layer and the Application Layer
E. Equilibrium-Adjustment and Common Law Reasoning
II. EXAMPLES OF EQUILIBRIUM-ADJUSTMENT IN FOURTH AMENDMENT LAW... 494A. New Government Tools: Thermal Imagers, Beepers, and GPS Devices
1. Thermal Imaging Devices
2. Beepers and GPS Devices
3. Sense-Enhancing Devices and Equilibrium-Adjustment
B. New Tools to Commit Crime: The Automobile Exception
1. How Automobiles Challenged the Privacy Balance of Year Zero
2. Equilibrium-Adjustment and the Automobile Exception
C. New Practices and New Crimes: The Subpoena Power and the End of the Mere Evidence Rule
1. Rejecting the Equivalence Between Orders to Compel and Direct Physical Entry
2. The End of the Mere Evidence Rule
D. Both Sides Use a New Tool: Telephone Network Surveillance
1. Contents of Telephone Calls: From Olmstead to Katz
2. Surveillance of Numbers Dialed
E. The Status Quo: Physical Entry into the Home, the Use of Undercover Agents, and the Law of Arrests
1. The Special Protections of the Home
2. Undercover Agents
3. The Law of Arrests
F. Defeating Countermeasures: Open Fields and Aerial Surveillance
1. Crossing over Fences
2011] EQUILIBRIUM-ADJUSTMENT THEORY
2. Aerial Surveillance
3. Defeating Countermeasures and Equilibrium-Adjustment
III. THE CASE FOR EQUILIBRIUM-ADJUSTMENT IN FOURTH AMENDMENT LAW... 525A. The Critical Role of Equilibrium-Adjustment in Fourth Amendment Law.............. 526 B. Equilibrium-Adjustment and Fourth Amendment Scholarship
C. The Coherence of Group Decisionmaking
D. Overcoming Lack of Empirical Knowledge
E. Equilibrium-Adjustment and Legal Stability
F. Judicial Delay as a Limitation on Equilibrium-Adjustment
AN EQUILIBRIUM-ADJUSTMENT THEORY
OF THE FOURTH AMENDMENT
Fourth Amendment law is often considered a theoretical embarrassment. The law consists of dozens of rules for very specific situations that seem to lack a coherent explanation. Constitutional protection varies dramatically based on seemingly arcane distinctions.
This Article introduces a new theory that explains and justifies both the structure and content of Fourth Amendment rules: the theory of equilibrium-adjustment. The theory of equilibrium-adjustment posits that the Supreme Court adjusts the scope of Fourth Amendment protection in response to new facts in order to restore the status quo level of protection. When changing technology or social practice expands government power, the Supreme Court tightens Fourth Amendment protection; when it threatens government power, the Supreme Court loosens constitutional protection. Existing Fourth Amendment law therefore reflects many decades of equilibrium-adjustment as facts have changed over time. This simple argument explains a wide range of puzzling Fourth Amendment doctrines, including the automobile exception; rules on using sense-enhancing devices;
the decline of the mere evidence rule; how the Fourth Amendment applies to the telephone network; undercover investigations; the law of aerial surveillance; rules for subpoenas; and the special Fourth Amendment protection for the home.
The Article then offers a normative defense of equilibrium-adjustment. Equilibriumadjustment maintains interpretive fidelity while permitting Fourth Amendment law to respond to changing facts. Its wide appeal and focus on deviations from the status quo facilitates coherent decisionmaking amidst empirical uncertainty and yet also gives Fourth Amendment law significant stability. The Article concludes by arguing that judicial delay is an important precondition to successful equilibrium-adjustment.
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ∗ Professor, George Washington University Law School. Thanks to Christopher Slobogin, Don Dripps, Carol Steiker, Nancy King, Scott Sundby, Richard Bonnie, Nita Farahany, Terry Maroney, Wayne Logan, Jeff Fagan, Thomas Crocker, Doron Teichman, Sara Sun Beale, Felix Wu, William Bridge, Chip Lupu, Jeffrey Bellin, Meghan Ryan, Jenia Turner, Larry Rosenthal, Tom Colby, Ed Swaine, Larry Mitchell, Cynthia Lee, Alan Morrison, Dan Solove, and Paul Butler, as well as workshops at the University of Pennsylvania Law School, the Vanderbilt University Law School, the George Washington University Law School, the Southern Methodist University Law School, and the Privacy Law Scholars Conference for comments on a prior draft.
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INTRODUCTIONThe Fourth Amendment regulates police investigations with a textually simple prohibition of “unreasonable searches and seizures.”1 Despite the Amendment’s concise text, judicial decisions interpreting the Fourth Amendment are infamous for their byzantine patchwork of protections. The caselaw includes hundreds of seemingly unrelated rules that answer whether and how much Fourth Amendment protection exists for different police practices. Scholars complain that the law is “a mess,”2 “an embarrassment,”3 and “a mass of contradictions.”4 Consider a few examples. If the police search a home, they need a search warrant.5 If the police search a car for the same evidence, however, no warrant is needed.6 If the police tap the contents of a phone call, they need a warrant; but if they record the numbers dialed from the phone, the Fourth Amendment doesn’t apply at all.7 The police need a warrant to point a thermal imaging device at a home to learn if the walls are hot, but the Fourth Amendment permits the police to fly an airplane over the home and photograph it without restriction.8 If investigators install a tracking device on a suspect’s car to follow its location, the Fourth Amendment does not apply unless the tracking device happens to enter a home, at which point a warrant is required.9 The police need a warrant to place a microphone on a public phone booth,10 but the Fourth Amendment doesn’t apply if they ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 1 U.S. CONST. amend. IV (“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”).
2 Ronald J. Allen & Ross M. Rosenberg, The Fourth Amendment and the Limits of Theory:
Local Versus General Theoretical Knowledge, 72 ST. JOHN’S L. REV. 1149, 1149 (1998) (noting that many commentators have expressed that the Fourth Amendment is “a mess”).
3 AKHIL REED AMAR, THE CONSTITUTION AND CRIMINAL PROCEDURE: FIRST PRINCIPLES 1 (1997).4 Craig M. Bradley, Two Models of the Fourth Amendment, 83 MICH. L. REV. 1468, 1468 (1985).
5 See Welsh v. Wisconsin, 466 U.S. 740, 748 (1984) (“[A] principal protection against unnecessary intrusions into private dwellings is the warrant requirement imposed by the Fourth Amendment on agents of the government who seek to enter the home for purposes of search or arrest.”).
6 See Wyoming v. Houghton, 526 U.S. 295, 300, 307 (1999).
7 Compare Katz v. United States, 389 U.S. 347, 353 (1967) (requiring a warrant for tapping a telephone call), with Smith v. Maryland, 442 U.S. 735, 742 (1979) (holding that the recording of numbers dialed does not constitute a search regulated by the Fourth Amendment).
8 Compare Kyllo v. United States, 533 U.S. 27, 34–35 (2001) (holding that a warrant is required for use of a thermal imaging device), with California v. Ciraolo, 476 U.S. 207, 215 (1986) (holding that aerial surveillance from public airspace is not a search).
9 See United States v. Karo, 468 U.S. 705, 714 (1984).
10 Katz, 389 U.S. at 353.
480 HARVARD LAW REVIEW [Vol. 125:476 send an undercover agent wearing a microphone into the target’s home.11 These Fourth Amendment rules can appear to be selected almost at random.12 The patchwork of results has made search and seizure law a theoretical embarrassment to scholars and judges alike. According to scholars, the law lacks any theoretical grounding. It is cobbled together from “a series of inconsistent and bizarre results that [the Court] has left entirely undefended.”13 In a recent interview, Justice Scalia expressed a similar disdain from his perspective as author of many Fourth Amendment opinions. “I just hate Fourth Amendment cases,” he complained.14 According to Justice Scalia, every case is so factspecific that any particular opinion merely answers “variation 3,542.”15 This Article offers a theory of Fourth Amendment development that explains and justifies the patchwork of Fourth Amendment rules, both in their form and the general outline of their content. It does so by identifying a dynamic it calls “equilibrium-adjustment.” Equilibrium-adjustment is a judicial response to changing technology and social practice. When new tools and new practices threaten to expand or contract police power in a significant way, courts adjust the level of Fourth Amendment protection to try to restore the prior equilibrium.
The result is a correction mechanism. When changing technology or social practice makes evidence substantially harder for the government to obtain, the Supreme Court generally adopts lower Fourth Amendment protections for these new circumstances to help restore the status quo ante level of government power. On the other hand, when changing technology or social practice makes evidence substantially easier for the government to obtain, the Supreme Court often embraces higher protections to help restore the prior level of privacy protection. Fourth Amendment protection resembles the work of drivers trying to maintain constant speed over mountainous terrain: judges add extra gas when facing an uphill climb and ease off the pedal on the downslopes.
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 11 United States v. White, 401 U.S. 745, 753 (1971).
12 See, e.g., Samuel C. Rickless, The Coherence of Orthodox Fourth Amendment Jurisprudence, 15 GEO. MASON U. C.R. L.J. 261, 261 (2005) (“If there is any statement to which virtually all constitutional scholars would agree, it is that orthodox Fourth Amendment jurisprudence is a theoretical mess, full of doctrinal incoherence and inconsistency, revealing not much more than the constitutionally unmoored ideological predispositions of shifting majorities of Supreme Court justices.”).
13 Silas J. Wasserstrom & Louis Michael Seidman, The Fourth Amendment as Constitutional Theory, 77 GEO. L.J. 19, 29 (1988).
14 Interview by Susan Swain with Antonin Scalia, Associate Justice of the United States Supreme Court, in Washington, D.C. (June 19, 2009), available at http://supremecourt.c-span.org/ assets/pdf/AScalia.pdf.
2011] EQUILIBRIUM-ADJUSTMENT THEORY This Article argues that Fourth Amendment caselaw reflects several generations of equilibrium-adjustment. New practices arise, begin to threaten the Fourth Amendment equilibrium, and then are addressed by judicial decisions that make the necessary adjustment. An appreciation of the continuing challenge of new tools and new practices to search and seizure law reveals the central role of equilibriumadjustment in the development of the Fourth Amendment. While existing doctrine is complex and fact-specific, it is not at all a “mess.” Rather, it is the product of hundreds of equilibrium-adjustments made over time. Those adjustments were usually made intuitively in response to felt necessities, but in rare cases were made out of a conscious recognition of the need for changes to keep the law in balance in the face of new practices and technological change.
This Article has three major goals. The first goal is to show how equilibrium-adjustment explains a great deal of the overall shape and substance of Fourth Amendment doctrine. Equilibrium-adjustment explains diverse topics such as the relatively modest protection for automobile stops and searches;16 the low protection for subpoenas;17 the Supreme Court’s treatment of telephone surveillance;18 the special protections for the home;19 the surveillance rules that govern locating devices;20 the lack of protection for undercover agents;21 the rules for sense-enhancing devices;22 the decline of the mere evidence rule;23 the open fields doctrine;24 and the rules on aerial surveillance.25 Equilibrium-adjustment reveals the common core of these disparate doctrines. It identifies a recurring dynamic that reconciles and explains a surprising amount of law that previously has not been linked.
The Article’s second goal is to defend equilibrium-adjustment as a tool for interpreting the Fourth Amendment. Changes in technology and social practice present a major challenge to the law of search and seizure. The police continuously devise new ways to catch criminals.