Professor Lawrence Rosenthal’s article “
Binary Searches and the Central Meaning of the Fourth Amendment
” was published in the
William & Mary Bill of Rights Journal
(Volume 22, No. 881, 2014).

Excerpt from the abstract:

rosenthal-willaim-and-mary-2014-small“Fourth Amendment jurisprudence is frequently accused of doctrinal incoherence. A primary reason is the persistence of two competing conceptions of ‘unreasonable’ search and seizure. The first is libertarian in character; it understands the Fourth Amendment’s command of reasonableness as establishing a constitutional boundary on investigative powers. On this view, the prohibition on unreasonable search and seizure keeps society free by limiting the government’s investigative reach. The second conception understands the Fourth Amendment’s prohibition as freedom against unjustified government intrusion. This conception of reasonableness is essentially pragmatic in character, balancing liberty and law-enforcement interests.

This article interrogates these competing conceptions by focusing whether a ‘binary search’ should be regarded as unreasonable under the Fourth Amendment. Binary search techniques reveal no more than whether there is probable cause to believe that an otherwise concealed area contains contraband or other evidence of criminality. In a binary search, the competing conceptions of the Fourth Amendment point toward different outcomes. On the libertarian conception, the Fourth Amendment would regard as unreasonable an effectively unlimited power to scrutinize otherwise private space through binary techniques. A libertarian Fourth Amendment demands limitations on binary searches. On the pragmatic conception, a binary search that discloses nothing more than the probable presence of contraband is supported by powerful law-enforcement interests, and is unlikely to threaten any legitimate liberty interest of the innocent. Therefore, it could readily be regarded as constitutionally reasonable even if unsupported by individualized suspicion of wrongdoing. As technology advances, the binary search will become increasingly important, as increasingly sophisticated and focused technologies are developed that can precisely target the presence of contraband or other evidence of criminality in both real and cyberspace.”

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Professor Rosenthal

Professor Rosenthal

Professor Lawrence Rosenthal
has been a professor of law at Chapman University Dale E. Fowler School of Law since 2005. After graduating from Harvard Law School, where he won the Fay Diploma and was an editor of the
Harvard Law Review
, Professor Rosenthal clerked for Judge Prentice Marshall of the United States District Court for the Northern District of Illinois and Justice John Paul Stevens of the United States Supreme Court. Professor Rosenthal entered the practice of law as an Assistant United States Attorney for the Northern District of Illinois, specializing in organized crime and public corruption prosecutions. In addition to teaching at Fowler School of Law, he continues to engage in litigation in the United States Supreme Court and other appellate courts, usually on a
pro bono

See more of Professor Rosenthal’s writings