March-April 2012

So tell us already! Do we have to get a warrant or not?

Emily Johnson-Liu

Assistant Criminal ­District Attorney in Collin County

A recent case from the United States Supreme Court, United States v. Jones,1 has created quite a stir over just exactly what the case might mean.2 At issue was the constitutionality of police action in installing and monitoring global positioning system (GPS) tracking devices in criminal investigations. All the justices agreed that the police action in Jones constituted a “search,” but they did not all agree on what conduct constituted the “search” and for what reason.3 The case produced three opinions, two majorities, and an additional test for determining if a search has occurred. But no one on the court addressed what was, for some, the most pressing question: whether installing or monitoring a GPS device requires probable cause and a warrant.

The underlying facts in Jones

The FBI and Washington D.C. police department were investigating Antoine Jones, a nightclub owner, for narcotics trafficking.4 Among other surveillance measures, officers attached a GPS tracking device to the underside of the Jeep Grand Cherokee that Jones drove exclusively.5 When they installed the device, it was parked in a public parking lot in Maryland. The officers had gotten a search warrant to install it, but the warrant authorized installation in D.C., not Maryland, and it had expired the day before the device was installed. For the next 28 days, the device relayed the Jeep’s location to within 50 to 100 feet, every 10 minutes, amassing over 2,000 pages of data about Jones’s movements. Once, during the four-week period, the officers had to replace the device’s battery, but again, they did so while it was in a public parking lot. The data from the tracking device established a pattern of movements that connected Jones to a stash house concealing 97 kilograms of cocaine and $850,000 in cash.6

    Jones was then indicted for conspiracy to distribute cocaine, and he filed a motion to suppress the GPS data. The trial judge ruled that Jones enjoyed the reasonable expectation of privacy only while the Jeep was parked in his attached garage, not while it was moving on public streets where it could be viewed by all. Consequently, the trial judge suppressed only the data showing the vehicle was in his garage. The remaining GPS data helped convict Jones, and he was given a life sentence. The D.C. Circuit Court of Appeals reversed the conviction, and the Supreme Court affirmed that decision.7 The entire court agreed that the action police took to get the GPS data constituted a “search,” but the justices disagreed over precisely what conduct constituted the search and why.8

The majority’s concern

For the five justices in the majority authored by Justice Scalia, what mattered most was that police trespassed onto Jones’s Jeep to monitor his movements.9 Their decision breathed new life into a test that most people believed had been discarded: that law enforcement’s physical intrusion onto property rights to find information (here, a trespass onto Jones’s Jeep) constitutes a “search.”10

    Not all observations by the police are “searches” that trigger Fourth Amendment concern. Officers can walk or drive down the street looking for criminal activity and view what is exposed to the public without implicating the Fourth Amendment. But the Supreme Court has vacillated on what more is needed to establish a “search” under the Fourth Amendment. At one time, the definition of a search turned on whether police trespassed onto the defendant’s property rights to gather information.11 Famously, in 1928, in Olmstead v. United States, the Supreme Court held that a wiretap was not a search when it tapped into phone wires on the street instead of at the defendant’s house or on his property.12 Because no trespass occurred, there was no Fourth Amendment search. But 40 years later, the court reversed itself in Katz v. United States and found that a microphone taped to the outside of a public phone booth violated the Fourth Amendment, even though there was no violation of the defendant’s property rights.13

    Post-Katz cases adopted the analysis of the concurrence in Katz, which found a search occurred because the police action violated a “reasonable expectation of privacy.”14 Until Jones, nearly everyone understood that Katz replaced the old common-law trespass test with the newer reasonable-expectation-of-privacy test.

    Scalia’s majority changes that. He reasons that physical intrusion onto Jones’s Jeep with the aim of collecting information would have been considered a “search” at the time the Fourth Amendment was adopted.15 The text of the amendment, Scalia explained, was concerned with maintaining the integrity of particular property.16 It reads: “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated” (my italics).17 Without overruling any prior cases, Scalia declares that the common-law trespassory test had existed alongside Katz all along.18 He distinguishes the post-Katz cases suggesting otherwise or adds them into the new formulation of the test for a “search.”19 Oliver v. United States, for example, had held that a search onto the defendant’s open field, even though a trespass at common-law, was still not a “search.”20 To account for Oliver in the common-law trespassory test, the majority adds the requirement that the government intrusion or trespass must involve one of the protected areas enumerated in the Fourth Amendment (persons, houses, papers, and effects).21 So, as the majority has now formulated a new test. To be a search, there must be:

    1) either:
        a) a common-law trespass onto the person, house, papers, or effects,22 or
        b) an invasion of a subjective expectation of privacy that society recognizes as reasonable (Katz), plus
    2) an attempt to find something or to obtain information.23
    Jones is sure to be credited for this newly articulated black letter law.

Also, after Jones, there are sure to be more debates over whether certain police conduct constitutes a “trespass” at common law. In applying the test to the facts in Jones, Scalia and the four other justices who joined him (Chief Justice Roberts and Justices Kennedy, Thomas, and Sotomayor) found that the officers’ installation and use of the GPS tracking device was a common-law trespass onto one of the protected areas enumerated in the Fourth Amendment (an “effect”) to obtain information.24 Consequently, a search occurred. Scalia’s opinion did not address whether it was also a search under the Katz reasonable-expectation-of-privacy analysis.25 And the opinion did not address the larger question of whether installation and monitoring of a GPS tracking device required probable cause and a warrant.

The concurrence’s ­concern

The four members concurring in the judgment, led by Justice Alito, would have kept Katz as the sole test for determining what is a search.26 Unlike the majority, these justices were not concerned with the installation of the GPS tracking device. The trespass onto the Jeep was “relatively minor,” even trivial.27 What mattered to these four Justices was the use of a GPS tracking device and the length of monitoring. Analyzing the issue under Katz, they decided that somewhere in the 28 days of tracking every movement Jones made in his Jeep, his reasonable expectation of privacy was violated.28 They concluded that for most offenses, longer term GPS monitoring (beyond what officers would have been able to gather manually from visual surveillance) violates privacy expectations.29 But these concurring Justices (Justices Alito, Ginsburg, Breyer, and Kagan) also determined that “relatively short-term monitoring of a person’s movements on public streets” was permissible under Katz.30

Sotomayor’s ­creation of a second majority

Justice Sotomayor signed onto Scalia’s opinion, the majority decision holding that a common-law trespass (even without a reasonable expectation of privacy) can constitute a search. But she also wrote a separate concurrence of her own, announcing her views of the case under the Katz analysis. She predicted that in future cases, law enforcement would likely be able to monitor GPS devices without actually physically intruding on the defendant’s property, and in such cases, Scalia’s resolution of the issue would not provide any guidance.31 In those cases, everything would turn on the Katz analysis. To guide those cases, Sotomayor announced her agreement with the Alito concurrence that “longer term GPS monitoring in investigations of most offenses impinges on expectations of privacy.”32 With her vote, Sotomayor formed a second majority holding in Jones that long-term monitoring constitutes a “search” under the Katz analysis—regardless of whether officers trespassed on the defendant’s property to obtain the GPS data. Sotomayor also had concern about short-term monitoring, but she was the only justice to voice her opinion in that direction.33

So is a warrant required?

None of the opinions in Jones addresses whether a warrant was required. The two majority holdings—that long-term monitoring or installation followed by monitoring constitutes a search—answer only whether the Fourth Amendment is implicated. Warrants are generally required for a search not to be an “unreasonable search,” but there are notable exceptions.34 The United States argued that there should be an exception in Jones, but the Supreme Court refused to consider the argument because the government had not argued it in the court of appeals.35 And the law prohibits parties from laying behind the log and waiting until a lower court has already ruled on an issue before advancing a new argument. So that issue was left for a future case.

    Jones takes no position on whether a warrant is required. At the same time, the safest approach is surely to seek a warrant. A search conducted without a warrant is per se unreasonable, subject only to a few specific, established, and well-delineated exceptions,36 and there is no currently recognized exception that expressly allows the installation of a GPS device without a warrant. The automobile exception permits warrantless searches of vehicles but has historically required probable cause to believe officers will find contraband or evidence within the vehicle itself.37 Further, in Texas, state law already requires an order from a district judge before installing a GPS tracking device, though the order requires only reasonable suspicion, not the probable cause that would be required with a warrant.38

    But sometimes, GPS is needed to gather the probable cause required for a warrant. In such cases, our best argument39 that a warrant is not required arises when officers do not have to install a tracking device and can merely monitor an already existing device or obtain data from GPS-enabled smartphones or vehicles with On-Star on a short-term basis. Although no opinion expressly waives the requirement of a warrant for short-term monitoring, the alignment of the justices in Jones suggests that the current court would likely vote that way. Alito and the three justices who joined him decided that, under Katz, short-term monitoring of a GPS device does not constitute a search. When the trespass is taken out of the equation, Scalia’s majority holds that Katz controls. Only one of the justices from Scalia’s majority (other than Justice Sotomayor) would need convincing that short-term monitoring was not a search under Katz (or that an exception to the warrant requirement should apply). Then Alito’s four-judge concurrence would constitute a majority.

    In such a case, a lot turns on the difference between short- and long-term monitoring. Justice Alito did not indicate where the line will be drawn. He suggests only that long-term monitoring for most offenses violates expectations of privacy—in part, because society does not expect law enforcement to monitor and catalogue every movement of a vehicle for weeks on end.40 So the length of time that the police would surreptitiously follow a car or person itself may provide a guide for how long police could monitor GPS data without a warrant. But as Alito counsels, “where uncertainty exists with respect to whether a certain period of GPS surveillance is long enough to constitute a Fourth Amendment search, the police may always seek a warrant.”41

    Where we cannot seek a warrant, the State still has several good arguments that reversal is not warranted—either through an exception to the warrant requirement or a rule that the exclusionary rule is not the proper remedy for the failure to obtain one. Remember to advance the alternative arguments at every level, and—who knows?—maybe one day we’ll get a clear answer.


1 United States v. Jones, No. 10-1259, 132 S. Ct. 945, 2012 WL 17117 (U.S. 2012).
2  See, e.g.,
3 Id., 2012 WL 171117, at *3 & at *11 (Alito, J., concurring).
4 Id., at *2.
5 The majority acknowledged in a footnote that the car was registered to Jones’s wife but that he was “the exclusive driver.”  The State never argued that this distinction made a difference, and indeed the court did not consider the Fourth Amendment significance of Jones’s status as an owner, either.
6 United States v. Jones, at *2-3.
7 Id. at *8.
8 Id. at *3; Id. at *11 (Alito, J., concurring).
9 Id. at *5-6.
10 Id. at *3, 5, 8.
11 Id. at *4; Kyllo v. United States, 533 U.S. 27, 31 (2001).
12 277 U.S. 438 (1928).
13 Katz v. United States, 389 U.S. 347, 351 (1967).
14 Smith v. Maryland, 442 U.S. 735, 740 (1979).
15 Jones, 2012 WL 171117, at *3.
16 Id.
17 U.S. Const. amend IV.
18 Jones, 2012 WL 171117, at *4-6.
19 Id.
20 Oliver v. United States, 466 U.S. 170, 183 (1984).
21 Id at *6 & n.8.
22 Id.
23 Id. at n.5.
24 Id. at *3.
25 Id. at *7.
26 Id. at *11 (Alito, J, concurring).
27 Id. at *15 (Alito, J, concurring).
28 Id. at *17 (Alito, J, concurring).
29 Id.
30 Id.
31 Id. at *8 (Sotomayor, J., concurring).
32 Id.
33 Id. at *9 (Sotomayor, J., concurring).
34 See, e.g., Carroll v. United States, 267 U.S. 132, 153 (1925) (establishing automobile exception).
35 Jones, 2012 WL 171117, at *8.
36 Arizona v. Gant, 556 U.S. 332, 338 (2009).
37 See, e.g., California v. Acevedo, 500 U.S. 565, 569, 579-80 (1991).
38 Tex. Code Crim. Proc. art. 18.21, §14.
39 For more educated guesses on how the current justices would rule on the questions left open by Jones, see Tom Goldstein, “Why Jones is still less of a pro-privacy decision than most thought,” (Conclusion slightly revised Jan. 31), SCOTUSblog (Jan. 30, 2012, 10:53 AM), 2012/01/why-jones-is-still-less-of-a-pro-privacy-decision-than-most-thought.
40 Jones, 2012 WL 171117, at *17 (Alito, J., concurring).
41 Id.