Diligence and Digiovanni: The Fourth Circuit’s Interpretation of Investigatory Traffic Stop Reasonableness after Arizona v. Johnson

BY Brian J. Litwak

Between 1986 and 2001, Operations Convoy and Pipeline, joint task forces between the Drug Enforcement Administration and state highway patrols, successfully seized over 2.9 million pounds of marijuana and $704 million in currency during routine traffic stops along major American interstates. As the number of these seizures increased, drug enforcement officials became highly skilled at asking “key questions” to determine whether a person was transporting narcotics. Counterbalancing the efficacy of the officers’ questioning techniques was the Fourth Amendment’s protection against “unreasonable searches and seizures.”


The Fourth Circuit’s holding in Digiovanni interpreted Johnson and Muehler as not eliminating the scope prong of the traditional Terry analysis altogether, but rather as combining the scope analysis within the duration analysis, forming a single diligence inquiry. This Recent Development argues that, in doing so, the Fourth Circuit correctly maintained the fact-specific nature logically underpinning Fourth Amendment reasonableness analysis. The Fourth Circuit’s reasoning, while not clearly articulated, effectively sketched the outline of a workable framework for analyzing the reasonableness of investigatory traffic stops without contradicting recent Supreme Court precedent.

DOWNLOAD PDF | 90 N.C. L. Rev.2142 (2012)