Warrantless Use of Drones

WRAL recently reported that “the Johnston County Sheriff’s Office . . . flew a drone over [private] property . . . to locate [stolen construction] equipment.” According to the story, the overflight may have been conducted without a warrant as “[t]here was no . . . warrant on file at the Johnston County Courthouse.” Can they do that?

Caveats. There is a lot that we don’t know. The story might be inaccurate or incomplete. There may have been a warrant in Johnston County that was sealed or overlooked. There may have been a warrant in another county, signed by a judicial official with statewide jurisdiction. There may have been exigent circumstances not described in the story. So for purposes of this blog post, let’s not focus on the details of the particular case in question. Instead, let’s ask a more general legal question: absent exigent circumstances, may a law enforcement agency conduct a drone overflight of private property without a warrant?

Constitutional considerations. I wrote about the Fourth Amendment limits on drone use in a prior post:

[A]ny law enforcement activity involving drones must comply with the Fourth Amendment. However, it is far from clear how the Fourth Amendment applies to drones. Will they be governed by the precedents concerning aircraft flyovers, like California v. Ciraolo, 476 U.S. 207 (1986), which generally allow considerable leeway to law enforcement? Does the increasing prevalence of hobbyists’ drones mean that there can be no reasonable expectation of privacy from drones? Or does the existence of inexpensive drones present a novel Fourth Amendment concern that will require a novel doctrine to address it, as the Supreme Court arguably charted new courses regarding GPS tracking in United States v. Jones . . . and regarding cell phone searches incident to arrest in Riley v. California . . . ?

I wrote that post in 2015, and despite the increasing frequency with which law enforcement agencies are using drones, I’m still not aware of a single case ruling on how the Fourth Amendment applies to drones.

One specific point of controversy may be the concept of “navigable airspace.” The court cases on plane and helicopter overflights generally say that so long as an aircraft is in “navigable airspace,” it isn’t infringing on anyone’s reasonable expectation of privacy. But the concept of “navigable airspace” lacks a bright line definition. Under 49 U.S.C. § 40102(32), it encompasses “airspace above the minimum altitudes of flight prescribed by [federal] regulations . . . including airspace needed to ensure safety in the takeoff and landing of aircraft.” Even experts in the field aren’t always sure how high that is. One lawyer opines that “navigable airspace boundaries are unclear below 500 feet, the minimum safe altitude for flight in non-congested areas.”

The situation is even hazier as to drones specifically, because drones are not subject to any minimum altitude of flight. They are often operated only a few dozen feet up. In fact, FAA regulations mostly prohibit them from flying above 400 feet. This calls into question whether the concept of navigable airspace retains any meaning for drones, as noted here and here.

For all these reasons, it is impossible to say what limits the Fourth Amendment puts on drone flights. The lower the flight, the greater the intrusion, but we just don’t know how low is too low.

Statutory considerations. Things are a bit clearer on the statutory side. In 2014, the legislature enacted G.S. 15A-300.1, entitled “restrictions on use of unmanned aircraft systems.” The statute generally prohibits anyone from “conduct[ing] surveillance” of a person, an occupied dwelling or its curtilage, or private property, without consent. It contains several exceptions for law enforcement, including surveillance with a warrant, under exigent circumstances, or of “gatherings to which the general public is invited.” It also allows an officer operating a drone “[t]o conduct surveillance in an area that is within a law enforcement officer’s plain view when the officer is in a location the officer has a legal right to be.” It includes a suppression remedy and creates a civil cause of action in case of violations.

This statute indicates that, as a general matter, warrantless drone surveillance is impermissible. Still, I can imagine at least two arguments that the state, or a law enforcement agency, could make regarding a drone overflight like the one described at the beginning of this post.

The first is that a brief, one-time flyover is not “surveillance” and so is not covered by the statute at all. A dictionary definition of “surveillance” is “continuous observation of a place, person, group or ongoing activity in order to gather information.” Is a drone overflight “continuous”? It certainly is nothing like the hours or days of visual surveillance that officers sometimes conduct in drug investigations. But in far different contexts, some courts have found that there is no fixed minimum length of time before presence and observation becomes “surveillance.” See, e.g., People v. Curtis, 820 N.E.2d 1116 (Ill. Ct. App. 2004) (holding, in a case in which the defendant was convicted of stalking by surveillance, that “there was no minimum period of time that defendant was required to remain present outside [the victim’s] car . . . in order for his actions to constitute surveillance”).

The second argument would be that the statutory plain view exception applies. This argument would depend on where the drone operator was located and what he or she could see, but suppose that the operator could see part of the parcel in question from his or her vantage point. Would that be enough to render the entire parcel part of the “area” that is within the officer’s plain view? That seems like a stretch to me, but the more the operator is able to see the more feasible the argument may become.

A related question, not raised by this case as far as I know, is whether an officer could fly a drone up over public land (or private land with the owner’s consent) and look from there onto adjoining private property. I don’t think the Fourth Amendment would prohibit that, as the plain view doctrine would apply: the drone would be in a place that it had a right to be. But under the statute as written, I think such activity would be impermissible if it amounted to “surveillance” as described above.

Further reading. If you can’t get enough drone law, check out my prior posts here, here, and here. There’s also a helpful recent law review article that addresses both law enforcement drones and drones operated by public code enforcement agencies. See Gregory S. McNeal et al., Warrantless Operations of Public Use Drones: Considerations for Government Agencies, 44 Fordham Urb. L. J. 703 (2017).