Can the police know where you’re going in your car?

January 28, 2013

Police stopEditor’s note: Over the next few weeks we will be featuring posts from our Westlaw Editorial team. This is the team that creates editorial enhancements for caselaw, including headnotes and Key Numbers. Enjoy the series: Westlaw Editorial’s Top Cases of 2012.

To understand the scope of the holding in a Supreme Court decision, it sometimes helps to know the question the Justices were answering, and the questions they left unanswered.

Media reports of the Supreme Court’s decision in U.S. v. Jones have often said the Supreme Court decided that the police need a search warrant before they attach a global positioning system (GPS) tracking device to a suspect’s car.

That’s not quite right.

As the Westlaw synopsis for the case makes clear, what the Court actually decided is that attaching a GPS tracking device to a vehicle, and subsequently using that device to monitor the vehicle’s movements on the public streets, is a “search” within the meaning of the Fourth Amendment.

Jones headnote

The Court did not decide whether a warrant was required, because the parties weren’t disputing that issue. The government had conceded that if a “search” occurred, a warrant was required.

While the Fourth Amendment generally requires search warrants, exceptions have been recognized by the Supreme Court. Whether, and when, an exception should apply for GPS devices is an issue for another day and another case.

The Court’s analytical route to its result is also of interest to lawyers. Justice Scalia’s majority opinion was grounded on the common-law concept of trespass to chattels, rather than the Katz test, which asks whether there is a reasonable expectation of privacy.

The concurring opinion of Justice Sotomayor, and the separate concurring opinion of Justice Alito, in which three other Justices joined, give some clues concerning how those Justices may view “search” questions arising from new technologies.

Justice Alito’s opinion also contained one of the more entertaining passages in the Court’s opinions for 2012: “[I]t is almost impossible to think of late–18th-century situations that are analogous to what took place in this case. (Is it possible to imagine a case in which a constable secreted himself somewhere in a coach and remained there for a period of time in order to monitor the movements of the coach’s owner? The Court suggests that something like this might have occurred in 1791, but this would have required either a gigantic coach, a very tiny constable, or both—not to mention a constable with incredible fortitude and patience.”