On the Job 

In its first review of GPS tracking, the U.S. Supreme Court ruled in January in United States v. Jones that law enforcement must have a search warrant before attaching a GPS tracking device to a subject’s vehicle. The court held that the attachment and information gleaned from monitoring a subject’s movements on public streets constitutes a “search” within the meaning of the Fourth Amendment.

In 2005, federal agents secretly attached a GPS device to a Jeep driven by Antoine Jones while it was parked in a public parking lot. The agents monitored Jones’ travels for 28 days and used the resulting data to help secure a conviction for his participation in a drug trafficking conspiracy.

When considering governmental intrusion using technology, those in the criminal justice system often think of the “reasonable expectation of privacy” rationale set forth in Katz v. United States in 1967.

In Jones, however, the court recognized the Katz formulation, but noted, “For most of our history, the Fourth Amendment was understood to embody a particular concern for government trespass upon the areas (‘persons, houses, papers, and effects’) it enumerates.” In reaching its decision in Jones, the court emphasized, “We have no doubt that such a physical intrusion would have been considered a ‘search’ within the meaning of the Fourth Amendment when it was adopted. … The government physically occupied private property for the purpose of obtaining information.”

Based on Jones, law enforcement agencies should ensure their policies require a search warrant before officers attach or monitor GPS tracking devices on target vehicles, even those located in public places.