Federal Appellate Court Affirms Warrant Required for GPS Tracking

UPDATE: Government attorneys continue to press for warrantless searches in GPS cases and significant, and unconstitutional, expansion of the so-called Good Faith Doctrine. On December 12, 2013, a majority of the Third Circuit agreed to re-hear the matter en banc and vacated the earlier, October 22, 2013, opinion. The information below still deals with the vacated opinion.

In US v. Katzin, the federal Third Circuit Court clearly affirmed that the 4th Amendment requires police to obtain a warrant before engaging in GPS tracking. The opinion protects residents of Pennsylvania, New Jersey, Delaware, and the Virgin Islands and partially resolves an allegedly unanswered question in US v. Jones (holding GPS tracking constituted a trespass but avoiding direct analysis of the so-called reasonable expectation of privacy). But even importantly, Katzin essentially reminds that police do not enjoy heads-I-win-tails-you-lose “immunity” under the court-derived Good Faith Exception to the 4th Amendment. The latter will likely be the more important legacy of Katzin.

4th Amendment Context

Katzin stems from the plain text of the federal 4th Amendment:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

While the Constitutional text was intended to be read and understood by anyone, courts have tortured the text for decades. Thus, the text now relies on a fairly complex idea known as  “reasonable expectation of privacy” (and by implication, when the government thinks you have it). But in 2011, the US Supreme Court

  1. modestly restored the plain-text protection for some property (thus the trespass theory in US. v. Jones) and
  2. apparently retained the reasonable expectation of privacy analysis  [See Katzin 16-17].

Whether this creates a two-tier analysis remains unclear but Jones certainly seems to hint that this is the case.

Despite Jones, a series of cases from the 1960s and 1980s remain influential—especially US. v. Katz (the origin of the so-called reasonable expectation of privacy analysis) and US. v. Knotts (holding that simple tracking beepers might be permissible in some cases without a warrant). But even Knotts recognized that 24 hour surveillance through simple tracking beepers without a warrant might not be Constitutionally permissible. [Knotts 283-84] The holding power of these older cases explain the issues in Katzin.

GPS Tracking Requires Warrant in 3rd Circuit

In Katzin, police attached a “slap-on” GPS to a van and tracked the suspects in a series of pharmacy burglaries. Notably, the police already had significant suspicion and evidence before using the GPS. But rather than obtaining a warrant, the police used the GPS without warrant to follow all the movements of the suspect’s vehicle for an undetermined time. To the Katzin Court, this violated the 4th Amendment. Basically, the Katzin Court reaffirmed that the 4th Amendment still means something. [Katzin 16-19] In other words, the proper procedure was to use the evidence (the police had already caught the suspects near a burglary scene with “electrical tools, gloves, and ski mask”s [Katzin 7]) to secure a warrant before undertaking the invasive GPS surveillance. As cases have repeatedly stated, police generally

  1. cannot invade personal space without a warrant or
  2. without a court-recognized exception to the Constitutional warrant requirement.

Thus, relying on fairly clear law, the Katzin Court held

[w]e thus have no hesitation in holding that the police must obtain a warrant prior to attaching a GPS device on a vehicle, thereby undertaking a search that the Supreme Court has compared to “a constable’s concealing himself in the target’s coach in order to track its movements.” [Katzin 20]

That is, despite arguments by the government in Katzin, the Court held the GPS revealed highly specific information about the suspect (thus invasive and objectively unreasonable) and no court-created exception to a warrant applied.

Heads-I-Win,-Tails-You-Lose Weakens

While the holding on warrantless GPS tracking is important and has wider technology-related application (reasserting that technology does not magically obviate the plain text of the law), Katzin makes an even more critical and broad-reaching statement of law related to the judicially created doctrine of good faith. In a nutshell, Katzin states that government actors (police) cannot engage in activity where the law is “unclear” and avoid accountability. In other words, police must err on the side of Constitutionality—not take matters in their own hands.

Good Faith is a court-created exception to a warrant requirement and applicable in narrow cases. As a general rule, if a government actor improperly collects evidence, the accused can challenge the admissibility of the obtained evidence. Essentially, this nullifies the evidence and probably undermines the case against the accused. According to courts, the suppression rule correctly penalizes government actors who do not follow the law by denying them the benefit of the improperly collected evidence—thus, acting as a deterrent. This follows centuries of common law where a wrongdoer should not benefit from wrongdoing.

But, courts added a good faith exception to the warrant requirement to essentially avoid an unfair outcome when government actors do follow binding legal authority (the law) but that authority is later determined wrong or erroneous. In other words, the government acted properly at the time but the error-of-law was discovered later. Thus, no penalty is appropriate because such penalty would have no reasonable deterrent effect.

Fatal for the government in Katzin, there was no legal authority approving GPS tracking without a warrant. Thus, the police cannot use GPS tracking without a warrant. Nevertheless, the government argued in a breathtaking expansion of good faith doctrine that even so, the good faith doctrine should apply because

  • the police “relied” on non-binding cases, that purport to allow GPS tracking without a warrant, to essentially fill-in-the-blanks for an unclear area of law. [See Katzin 40].

The latter essentially would create a startling broad, heads-I-win-tails-you-lose rule and turns the good faith rule on its head.

The Katzin Court flatly shot-down the government’s argument, especially the heads-I-win argument  and reaffirmed the narrowness of the Good Faith Exception:

the  Supreme Court has held [the good-faith] exception to cover situations where law enforcement personnel have acted in objectively reasonable reliance on some seemingly immutable authority or information that justifies their course of action. [Katzin 36]

[T]he 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. [Katzin 56]

The court held that good-faith means exactly what is says: police reasonably relying on some clearly binding legal authority where the authority plainly and explicitly sanctions an action and the police are required to follow that law does not warrant a penalty for thus following that authority. [See Katzin 40]  For example, if a court specifically holds that police with a warrant may kick down a door without notice, then police executing a warrant by kicking down a door should not be penalized for the action. Thus, the good-faith exception is not a general license for “heads I win, tails you lose” or “ends justify the means” actions.

For some reason, however, the natural implications of good faith seem to pose issues for some government actors—leading to the strained arguments by the government in Katzin. As follows from the example above, if there is no court case specifically addressing the issue of kicking down doors with a warrant, police may be penalized (evidence suppressed) if they kick down doors. The penalty assures that the government does not benefit from its own wrongdoing in an unclear area of law. That is, good faith implicitly avoids Scylla and Charybdis decision-making by the police by expressly noting that the good faith rule only applies when there is “immutable authority.” No immutable authority, no permissible action. A clear and easy rule (and also consistent with the Constitution).

The point here is not that all police are acting improperly or are trying to get-away with something. The point is that government actors must adhere to binding law and operate within the Constitution. The good faith exception was devised to avoid rock-and-a-hard-place situations triggered by unclear areas of law such as cases where the police followed plainly defined and required procedures, but those procedures were somehow mistaken or erroneous. A government actor must refrain from action unless law clearly allows otherwise—erring on the side of Constitutionality. Under these conditions, it is not fair to apply a penalty because the penalty cannot act as a deterrent (because the police acted as they should at the time of action). But, stretching that doctrine to the breathtaking scope posed by the government in Katzin undermines effective (and Constitutionally required) constraints on government actions (and directly violates separation of powers). That is troubling at best.


While Katzin will likely be cited for the newsworthy GPS issue and general statement on technology issues, the real effect of Katzin is found in re-asserting the narrowness of the good faith exception (as Section IV [34-56] in Katzin closely scrutinizes). The Katzin Court clearly reaffirmed that the “good faith” exception is a narrow exception that still means just what it says: police validly and legally relying on binding precedent should not be penalized for relying on that binding precedent. Put simply, the government cannot improvise “heads I win, tails you lose”  police-work without incurring penalties. That reaffirmation will likely have significant effects on other unclear areas of law such as cell phone tracking.