By Nicholas Ulrich

Last week, two events further clouded the issue of whether law enforcement officers need a warrant to place a GPS tracking device on someone’s vehicle. After the Supreme Court’s landmark 2012 decision United States v. Jones, which brought GPS trackers within the scope of the Fourth Amendment, only one circuit court had definitively spoken on whether a warrant is required before police can use the devices. In United States v. Katzin, the Third Circuit unequivocally stated that a warrant is required before law enforcement can place GPS tracking technology on someone’s vehicle. Last week, however, the court agreed to grant an en banc rehearing of Katzin. This vacates the original decision. In addition, the Second Circuit decided United States v. Aguiar, which dealt with a comparable GPS tracking situation. The Second Circuit, however, did not address whether a warrant is required. The court merely alluded in dicta that Jones had changed “the landscape.”

In Jones, the Supreme Court concluded that installing a GPS tracker onto someone’s vehicle is a “search” within the meaning of the Fourth Amendment. This decision overruled decisions in many lower courts, which had held that the placing of a GPS tracker does not constitute a search because a person has no reasonable expectation of privacy driving on a public highway. Check out our blog post following the Jones decision.

Jones, however, did not entirely resolve the controversy: the court left open the question of what law enforcement officers must do before they can place a GPS tracker on a vehicle. Essentially, the question is whether law enforcement officers can place a GPS tracker based merely on a reasonable suspicion, or if they must obtain a warrant. There is also a third possibility, which lies in the middle, and would allow an officer to place a GPS tracker if the officer believed there was probable cause (as opposed to requiring the officer to satisfy a neutral magistrate on probable cause).

The Third Circuit’s Katzin opinion from October expressly addressed and dismissed both the reasonable suspicion standard and the probable-cause-without-a-warrant standard in favor of the warrant requirement. The panel applied the familiar rule that warrantless searches are per se unconstitutional, unless they fit within specifically enumerated and narrow exceptions (such as the search incident to arrest exception).

In Aguiar, the Second Circuit dodged the warrant question by deciding the issue under the exclusionary rule. The panel concluded that the district court did not need to exclude the evidence at issue because it fell within the good-faith exception to the exclusionary rule. The good-faith exception generally applies when there is a substantive change in constitutional protections because of a recent ruling and officers relied on the prior state of the law. The court essentially decided that since the action was considered constitutional under existing precedent at the time the search occurred (pre-Jones), the officers acted in good faith, and the evidence need not be excluded. After applying the good-faith exception, the court merely stated in dicta that “post-Jones, the landscape has changed, and law enforcement will need to change its approach accordingly.” Reading this dictum in combination with the opinion as a whole, the court seems to be implying that a warrant is now required to place a GPS tracker, though this is by no means certain.

Because the Third Circuit vacated Katzin and the Second Circuit dodged the issue, the question as to whether a warrant is required for a GPS tracker is still wide open. Justice Scalia, author of the majority in Jones, stated that when the government uses a GPS tracker it is “physically occup[ying] private property for the purpose of obtaining information.” Such a characterization strongly suggests a warrant should be required. If no warrant is required, police may be able to track individuals based solely on their suspicion that illegal activity has occurred.