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Supreme Court Rules on GPS Tracking Case

On Jan. 23, 2012, in United State v. Jones, the long awaited Global Positioning System (GPS) tracking device case was finally decided by the Supreme Court.

However, in classic fashion, the Court side-stepped and failed to answer two out of the three questions to which we the police needed an answer.

Question #1:

Is the installation of a GPS tracking device on a private vehicle (in a public place) and the subsequent (corresponding) monitoring of the vehicle’s movements (in public areas) a “search” within the meaning of the Fourth Amendment? The Court answered this question with a“yes,” although earlier Supreme Court cases involving electronic “beepers” led police and many legal experts to expect the Court to answer “no.”

Question #2:

If such actions constitute a “search” within the meaning of the Fourth Amendment, does such a search require prior probable cause or would some lesser justification, like reasonable suspicion, suffice? The Court does not answer this question. Notably, if such actions do not constitute a search, then no factual justification is required—not reasonable suspicion, not probable cause, not anything.

Question #3:

If such actions constitute a “search” within the meaning of the Fourth Amendment, does such a search require a prior warrant? The Court does not answer this question. The earlier Supreme Court decisions on “beepers” held that no “reasonable expectation of privacy” was violated, so no warrant was required.

The Facts of the Case

Pursuant to a joint task force drug investigation conducted by the FBI and D.C. Metropolitan Police, the federal district court in the District of Columbia issued a search warrant authorizing the installation and monitoring of an electronic tracking device on a vehicle that was driven exclusively by Jones but registered to his wife. The search warrant authorized installation of the device in the District of Columbia within 10 days from the issuance of the warrant.

The police attached the device to Jones’s vehicle (in Maryland) 11 days after the warrant was issued. They then collected data on the vehicle’s movements for the next 28 days. Information gathered from the device while the vehicle was in public areas was used to convict Jones on multiple drug related federal charges.

Because the terms of the warrant were so plainly violated, the matter was reviewed as a warrantless search case. The federal circuit court of appeals ruled in favor of Jones, saying the police violated the Fourth Amendment with their warrantless use of the GPS device on his vehicle, and the Supreme Court agreed to hear the warrantless search issue.

Things were off to a bad start. The government lawyers had to concede the police did not comply with the requirements of their own warrant. Undaunted, the government lawyers argued the warrant wasn’t necessary because use of the tracking device was not a “search.” Therefore the warrant wasn’t needed in the first place. Consequently the violation of it was legally insignificant.

The government’s lawyers put forward the alternative argument that if the police conduct was indeed a search, then it was a reasonable search, especially grounded as it was in probable cause. But since the government did not make that argument in the lower courts and it could not be brought up for the first time at the Supreme Court level.

The government relied on the earlier Supreme Court decisions, United States v. Knotts and United States v. Karo, to support their argument that attaching the GPS device to the underbelly of Jones’s vehicle, while it was parked in a public area, and subsequently monitoring the public area movements of that vehicle, was not a search.

The logic behind that argument was that those actions did not intrude upon a “reasonable expectation of privacy”—a term created in Katz v. United States to define “search.” The government’s theory was consistent with the Court’s line of reasoning originally expressed in Katz, and reiterated in Knotts and Karo, so most experts expected the Court to analyze this case in the same vein. But they didn’t.

Supreme Court’s Analysis


Remember the actual words of the Fourth Amendment? 

In its own terms, it protects the right of the people to be secure “in their persons, houses, papers, and effects” against unreasonable government searches and seizures. 

So, in perhaps the simplest and purest historical sense of that language, the Fourth Amendment protects citizens from government intrusions on personal property, as such property existed in the 1700s. 

A succession of search and seizure cases since adoption of the Fourth Amendment attempted to explain exactly what are searches, what are seizures, and when are they reasonable. 

This effort led to the decision in Katz v. United States, 389 U.S. 347 (1967), which extended Fourth Amendment protections beyond the physical boundaries of “persons, houses, papers, and effects” as originally expressed by the founders. 

As electronic technology rapidly advanced, the Court strained to delineate the boundaries of privacy and Fourth Amendment protections (as in Knotts and Karo). In Jones, the Court reached back to this original Fourth Amendment language and addressed the “search” question without relying on the more contemporary “reasonable expectation of privacy” cases. 

The Jones majority says a vehicle is an “effect” within the meaning of the Fourth Amendment, and, as such, it is constitutionally protected property. 

When police attached the GPS tracking device to the vehicle, they encroached on that protected property, committing an old fashioned “trespass” against that property. 

The Jones case emphatically states, “The Government physically occupied private property for the purpose of obtaining information,” and that is a “search” in truest sense of the Fourth Amendment.


According to the Court in Jones, the Katz concept of protecting people’s “reasonable expectation of privacy” is an additional protection against unreasonable government searches. 

Katz adds to the originally intended protections of people and property that was created by the Fourth Amendment when adopted.  

In Jones, the police use of the tracking device was a “search” within the original meaning of the Fourth Amendment language and therefore the Court did not need to consider the “reasonable expectation of privacy” concepts created in Katz. 

The Court’s reliance on 1700s terminology to answer a contemporary high-tech search and seizure question, rather than on the modern definition of “search,” has certainly muddied the waters in this area. 

Going forward from Jones, lower courts may analyze GPS tracking cases under this Jones-style physical intrusion theory, or the more expected Katz-style “reasonable expectation of privacy” approach, or both. 

Considering the line of reasoning offered by the various justices in Jones, it seems the Court is likely to revisit the Katz type analysis in future cases that involve more high-tech surveillance techniques, but we won’t know for sure until that case comes. 

Meanwhile, we are reminded of what we already knew, it’s safer to get a warrant. 

Of course, that will require prior probable cause.

Randy Means is a partner in Thomas & Means, a law firm specializing entirely in police operations and administration. He has served the national law enforcement community full time for more than 30 years and is the author of “The Law of Policing,” which is available at He can be reached directly at

In her 20-year career with law enforcement, Pam McDonald has been a patrol officer, a felony investigator, a felony prosecutor and a college professor in the area of police law. She currently serves as head of the Thomas & Means publications section and assists Randy Means in much of his work. She can be reached at

Published in Law and Order, Mar 2012

Rating : 8.0

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