[JURIST] The US Court of Appeals for the Third Circuit [official website] ruled [opinion, PDF] Tuesday that a warrant is required prior to the government’s attachment of a global positioning system (GPS) [JURIST news archive] device to a vehicle for the purposes of monitoring the vehicle’s movements. In December 2010 FBI agents affixed a “slap-on” GPS tracker to the exterior of Harry Katzin’s van following a string of pharmacy burglaries that Katzin and his two brothers were suspected of committing. The GPS tracker eventually led to the discovery of pill bottles and equipment inside the van just moments after local law enforcement investigated a break-in at a Rite Aid where the van had been parked. Responding to the brothers Katzin’s legal challenge attempting to suppress the evidence uncovered in the van, the Third Circuit stated:

The deterrent effect of suppression in this case is substantial and outweighs any harm to the justice system. The police acted in the face of unsettled law at a time when courts were becoming more attuned to the argument that warrantless GPS surveillance violated the Fourth Amendment. Excluding the evidence here will incentivize the police to err on the side of constitutional behavior and help prevent future Fourth Amendment violations.

After the proceedings, American Civil Liberties Union (ACLU) attorney and counsel for Katzin, Catherine Crump, remarked [Wired report] on the necessity of court supervision over the use of powerful tracking technology, stating, “Today’s decision is a victory for all Americans.”

In January 2012 the Supreme Court ruled [JURIST report] in United States v. Jones [SCOTUSblog backgrounder], a precursor to Tuesday’s Third Circuit decision. In an opinion written by Justice Antonin Scalia, the court held that the government’s attachment of a GPS device to a vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a search under the Fourth Amendment [text]. The government argued that under US v. Knotts [opinion], a GPS tracker is as permissible as monitoring a car by using a beeper inside the car for tracking purposes. Respondent’s attorney argued that placing the GPS in the car created a seizure of the vehicle. JURIST Guest Columnist Jim Harper [professional profile], Director of Information Policy Studies at the Cato Institute [official website], argued in a piece for JURIST that the Supreme Court should use US v. Jones as an opportunity to reaffirm Fourth Amendment protections against unreasonable search and seizure, particularly in light of technological advances.