Article by Ric Simmons
In the past few decades, law enforcement agents have increasingly relied on “binary” searches, those searches which can only reveal evidence of illegal activity and no other fact. Though only two binary search techniques are currently employed by law enforcement personnel, canine sniffs and chemical field tests for drugs, many other types of binary search techniques are under development, such as handheld gun detectors, software that searches e-mail for illegal material, and facial recognition technology.
In this Article, the author discusses the Fourth Amendment's binary search doctrine, including the Supreme Court's recent decision of Illinois v. Caballes, in which the Court held that a canine sniff conducted without grounds for suspicion is not a search subject to the Fourth Amendment because it discloses only the presence or absence of contraband. The author then identifies two questions the Caballes Court failed to answer: What types of surveillance qualify as a binary search? What limits (if any) should be placed on the use of such binary searches?
In determining what types of surveillance qualify as a binary search, the author proposes that trial judges should conduct an independent evaluation of any technique which the prosecutor claims to be a binary search to determine whether a positive alert obtained using the technique indicates the existence of contraband, perhaps beyond a reasonable doubt. As to placing limits on the use of binary searches, he suggests that if the technique causes the subject of the search delay or physical invasion, the officer's use of the technique should be evaluated under existing Fourth Amendment principles.
About the Author
Ric Simmons. Professor of Law, Moritz College of Law at the Ohio State University.
Citation
80 Tul. L. Rev. 411 (2005)