Aerial Trespass and the Fourth Amendment.

• Author: Khalil, Randall F.

Table of Contents Introduction I. Current Fourth Amendment Doctrine.., A. The Katz "Reasonable Expectations" Test Applied to Aerial Surveillance 1. Positive Law 2. Frequency of Public Access 3. Disruptiveness 4. Sensitivity of Information 5. Intent to Surveil B. The Jones Intrusion Test C. Long Lake Township v. Maxon II Defining Aerial Trespass A. The Ad Coelum Principle B. Erosion of the Ad Coelum Principle in the Aviation Era C. Aerial Trespass Today 1. Clear Inferences 2. The Ambiguous Middle Area 3. Limited Role for State Law III. Aerial Trespass and the Fourth Amendment A. The Fourth Amendment Aerial Trespass Test 1. Proposal 2. Evoking Sabo 3. "Interference with Actual Use"? B. The Aerial Trespass Test Applied 1. Ciraolo and Dow Chemical 2. Riley 3. Maxon C. Addressing Counterarguments D. Advantages of the Aerial Trespass Approach Conclusion INTRODUCTION

In May 2018, Long Lake Township in Northern Michigan hired a drone operator to conduct surveillance on Todd Maxon's backyard on the suspicion he was in violation of the municipality's zoning ordinance. (1) The Michigan Court of Appeals held that this drone surveillance violated the Fourth Amendment's protection against unreasonable searches and seizures. (2) Maxon appears to be the first time a United States court declared an instance of aerial drone surveillance a search triggering the Fourth Amendment. The court's analysis illustrated the reality that Fourth Amendment doctrine, as applied to aerial searches, is unsettled and unpredictable.

The dominant Fourth Amendment test from Katz v. United States states that a search triggers the Fourth Amendment when a government actor violates a person's "reasonable expectation of privacy." (3) Between 1967 and 2012, the Katz "reasonable expectations" test was the sole Fourth Amendment test. Courts first began to apply the Fourth Amendment to aerial surveillance in the 1970s in cases involving fixed-wing aircraft and helicopters. (4) In 2012, the Supreme Court recognized an alternative trespass-based Fourth Amendment test in United States v. Jones, which held that the Fourth Amendment is triggered when a government actor physically intrudes into a constitutionally protected space with intent to obtain information. (5) Since 2012, no court has dispositively applied the Jones intrusion test to aerial surveillance.

Clarity remains as important as ever in this area of the law. Use of drones to conduct aerial surveillance has become cheap and easy, (6) and law enforcement's use of drones will continue to expand. (7) This Note argues that the Jones trespass test can apply to aerial surveillance more workably than the existing Katz approach, and would lead to more predictable results and better secure citizens' privacy. Part I recounts existing Fourth Amendment doctrine and historical applications of the Katz test to aerial surveillance. Part II examines the history of aerial trespass in Anglo-American law and attempts to answer the yet-unresolved question of how far landowners' property rights extend into the air (at least for Fourth Amendment purposes). Part III explains how an aerial trespass test would work and applies it to several prominent aerial surveillance cases decided under Katz.

1. Current Fourth Amendment Doctrine

   The Fourth Amendment states, "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated." (8) The Court has explained that the purpose of the Fourth Amendment is to protect "the privacy and security of individuals against arbitrary invasions by governmental officials." (9) Courts have long looked to property law for guidance in interpreting the reach of the Fourth Amendment. (10) Formally, there are two distinct inquiries in a Fourth Amendment analysis: (1) whether the government has conducted a search or seizure under the Fourth Amendment; and (2) if so, whether the search or seizure was reasonable. (11) Courts frequently blur the line between these two inquiries. (12) This Note concerns only the first question: when the Fourth Amendment is triggered.

   1. The Katz "Reasonable Expectations" Test Applied to Aerial Surveillance

      To determine whether a Fourth Amendment search has occurred, the Supreme Court has historically applied the Katz "reasonable expectation of privacy" test. (13) Under Katz, a Fourth Amendment search occurs when the government violates a subjective expectation of privacy that society recognizes as reasonable. (14) In the context of aerial surveillance, the most important factor the Supreme Court considers is positive law--specifically FAA regulations-and whether the airspace from which the surveillance took place was open to the public. The second most important factor is the probability or frequency of public access. Finally, the lower courts have viewed "disruptiveness" as another important factor; sensitivity of setting and government intent have also proven lesser, but present, factors. The Supreme Court has never found aerial surveillance to be a Fourth Amendment search, but lower courts sometimes do.

      1. Positive Law

         Whether FAA regulations permit public access to airspace was the decisive factor in two of the three aerial surveillance cases decided by the Supreme Court and a necessary factor in the third. In Ciraolo v. California, law enforcement flew a fixed-wing aircraft 1,000 feet above a defendant's backyard to search for marijuana plants. (15) The Court held that this was not a Fourth Amendment search; the defendant's expectation of privacy was "unreasonable" because "[a]ny member of the public flying in [the] airspace who glanced down could have seen everything that these officers observed." (16) In Dow Chemical, decided the same day as Ciraolo, the EPA hired an aerial photographer to take pictures of the Dow Chemical's Midland, Michigan plant from various altitudes no lower than 1,200 feet as part of an emissions compliance investigation. (17) The Court held that the aerial photography was not a Fourth Amendment search because the aircraft was lawfully within navigable airspace the entire time the photographs were taken. (18)

         Lower courts also routinely find that aerial surveillance is not a Fourth Amendment search when there is lawful public access to the airspace. (19) And in at least one case, lack of lawful public access led a court to conclude that the Fourth Amendment was triggered. In 2009, the Ohio Court of Appeals held in State v. Little that police helicopter surveillance conducted 100 to 600 feet above the defendants' property triggered the Fourth Amendment because the pilot operated illegally in "closed" airspace near the Dayton International Airport. (20) The court concluded that the aircraft violated the defendants' reasonable expectation of privacy "when it viewed the contraband on [their] property" within the FAA-restricted airspace. (21)

         Lack of lawful public access was also relevant in People v. Sneed--the first aerial surveillance Fourth Amendment case decided in any court in the United States. (22) There, the California Court of Appeal suggested that a police helicopter hovering twenty to twenty-five feet above the defendant's backyard was "probably illegal." (23) But this analysis was not necessary to the court's conclusion. (24)

      2. Frequency of Public Access

         The second most important factor in Fourth Amendment aerial surveillance case law is the probability or frequency of public access into the airspace at a given altitude. This was the decisive factor in Justice O'Connor's concurring opinion in Florida v. Riley, (25) which provided the critical fifth vote concluding that a helicopter flyover was not a Fourth Amendment search. In Riley, a law enforcement helicopter hovered 400 feet over the defendant's home for several minutes and discovered marijuana growing in a greenhouse. (26) A fractured Court held that this did not implicate the Fourth Amendment. Justice White's plurality opinion reasoned that it was "of obvious importance that the helicopter ... was not violating the law," because FAA regulations provided that "[a]ny member of the public could legally have been flying over Riley's property in a helicopter at the altitude of 400 feet and could have observed Riley's greenhouse." (27)

         But O'Connor's concurrence argued that FAA regulations concerned safety rather than compliance with the Fourth Amendment, and that the test for determining if the defendant had a reasonable expectation of privacy should instead be "whether the helicopter was in the public airways at an altitude at which members of the public travel with sufficient regularity." (28) O'Connor concluded without evidence that such overflights were sufficiently common and, therefore, Riley's expectation of privacy was unreasonable. (29) Lower courts often similarly assume, without justification, that frequent public access defeats a reasonable expectation of privacy, (30) but sometimes they require proof that overflights were, in fact, common to show the expectation of privacy was not reasonable at all. (31)

      3. Disruptiveness

         In the small subset of aerial surveillance cases in lower courts that concluded the Fourth Amendment was triggered, disruptiveness was often the critical factor. Justice White's plurality opinion in Florida v. Riley suggested that it was relevant that the helicopter did not "interfere^ with respondent's normal use of the greenhouse or of other parts of the curtilage" and that there was "no undue noise, and no wind, dust, or threat of injury." (32) Lower courts subsequently latched onto this dictum.

         In 1990, the Pennsylvania Supreme Court held in Commonwealth v. Oglialoro that aerial surveillance of a barn triggered the Fourth Amendment when a helicopter hovered fifty feet above the barn for fifteen seconds and passed over the barn at least three times over five minutes. (33) It was critical to the court that the helicopter flight posed a risk of harm to...