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Randomization and the Fourth Amendment

80 Pages Posted: 25 Aug 2010 Last revised: 17 Sep 2010

Bernard E. Harcourt

Columbia University; Columbia University

Tracey L. Meares

Yale University - Law School

Date Written: August 25, 2010


Randomized checkpoint searches are generally taken to be the exact antitheses of reasonableness under the Fourth Amendment. In the eyes of most jurists, checkpoint searches violate the central requirement of valid Fourth Amendment searches – namely, individualized suspicion. We disagree. In this article, we contend that randomized searches should form the very lodestar of a reasonable search. The fact is that the notion of “individualized” suspicion is misleading; most suspicion in the modern policing context is group-based and not individual specific. Randomized searches by definition are accompanied by a certain level of suspicion. The constitutional issue, we maintain, should not turn on the question of suspicion-based versus suspicionless police searches, but on the level of suspicion that attaches to any search program and on the evenhandedness of the program. In essence, we argue for a new paradigm of randomized encounters that satisfy a base level of suspicion and that will provide the benefits of both privacy-protection (by ensuring a minimum level of suspicion) and evenhandedness (by cabining police discretion), the very values we wish to protect through the Fourth Amendment.

Keywords: Fourth Amendment, Individualized Suspicion, Reasonableness, Probable Cause, Articulable Suspicion, Stop-And-Frisk, Checkpoint Searches, Border Patrol Searches, Randomized Searches, Randomization, Drug Testing, School Searches, Roadblocks, Warrants

Suggested Citation

Harcourt, Bernard E. and Meares, Tracey L., Randomization and the Fourth Amendment (August 25, 2010). U of Chicago Law & Economics, Olin Working Paper No. 530; U of Chicago, Public Law Working Paper No. 317. Available at SSRN: or

Bernard E. Harcourt (Contact Author)

Columbia University ( email )

Jerome Green Hall, Room 515
435 West 116th Street
New York, NY 10027
United States


Columbia University ( email )

7th Floor, International Affairs Bldg.
420 W. 118th Street
New York, NY 10027
United States


Tracey Louise Meares

Yale University - Law School ( email )

P.O. Box 208215
New Haven, CT 06520-8215
United States
203-432-4074 (Phone)
203-432-4876 (Fax)

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