There was nothing particularly special about the Ford minivan that passed by a Kansas state trooper watching traffic on Interstate 70 one morning in May 2010, an appeals court said in recounting the traffic stop that would compel the court to confront a clash between technology and the Fourth Amendment.
The officer called in the license plate—a Colorado 30-day temporary registration tag. A dispatcher reported "no return"—indicating, prosecutors would later argue, that it might be forged or that something else was amiss. The vehicle stop ensued. The driver consented to a search. In a secret compartment near an air vent on the dashboard, the trooper found more than a pound of methamphetamine.
