Jordan Hughes, MJLST Staffer
The past several months have once again shone a spotlight on the difficulty of holding police and law enforcement accountable for their actions. The American public has become more aware than ever of the unions and structures in place to shield officers from liability. Despite years of DOJ investigations and investigative reporting into the procedures of departments around the country, many regular police practices remain hidden from the public eye. Including the use of secretive new technologies that allow for unprecedented levels of discretion—and unprecedented potentials for abuse.
The Hailstorm is one such dragnet-style electronic capturing device that over 85 federal and state enforcement agencies have used largely in secret for more than two decades. This past spring, the 4th Circuit joined the fledgling ranks of federal courts asked to grapple with constitutional questions raised by the elusive technology. Baltimore police used a Hailstorm in 2014 to locate Kerron Andrews, who had an outstanding arrest warrant. Andrews v. Balt. City Police Dep’t, No. CCB-16-2010, 2018 U.S. Dist. LEXIS 129523, at *4 (D. Md. Aug. 1, 2018). The device enabled Baltimore police to pinpoint the apartment building where Andrews was sitting, despite having been unable to find him using standard location information released to them by his phone carrier. The police never disclosed the device during their surveillance, citing instead a “pen register order” as authorization for its use. A Maryland state court held that the government violated Andrews’ Fourth Amendment rights through use of the Hailstorm, and a state appellate court upheld that decision. Andrews then sued the police department in a federal district court, but the federal court considered the search constitutional and granted summary judgment against him. Andrews appealed.
The 4th Circuit, in Andrews v. Balt. City Police Dep’t, No. 18-1953, 2020 U.S. App. LEXIS 9641 (4th Cir. Mar. 27, 2020), both acknowledged the serious constitutional questions at stake and declined to make a ruling on them due to a lack of information. The district court was directed on remand to make findings concerning the Baltimore Police Department’s practice regarding Hailstorm technology, as well as the extent of constitutional intrusions involved in the search. Whatever the outcome, the 4th Circuit is likely to hear this case again. When it finally does, the court will have to decide how to apply the Fourth Amendment to a technology that may be fully incompatible with the freedom from broad and general searches that it typically guarantees.
What is a Hailstorm?
The “Hailstorm” is a model of “cell site simulator” technology sold by Harris Corporation. Other commonly used Harris models include the “StingRay,” “TriggerFish,” and “KingFish.” Generically, these devices are known as international mobile subscriber identity (“IMSI”) catchers.
IMSI catchers essentially mimic a wireless carrier’s base station, causing cell phones to communicate their unique identifiers and location data to the device even when they’re not in use. They function as a dragnet, capturing the unique numerical identifiers of all wireless devices within a particular area. The technology provides both identification and location data for devices. It is precise enough for law enforcement to narrow a device’s location to six feet, and to identify the exact unit a device is in from outside a large apartment complex. IMSI catchers are also capable of capturing the contents of communications, although there has not been a disclosed instance yet of law enforcement using an IMSI catcher in this fashion. IMSI catchers are small, and can easily be handheld or mounted on vehicles or drones.
What is the concern?
The Hailstorm raises a number of concerns under the Fourth Amendment—the constitutional provision meant to protect Americans from unreasonable searches and seizures. The ACLU, in a 2014 guide for defense attorneys, outlined the major Fourth Amendment questions that arise with the use of any IMSI catcher. These include:
- Level of scrutiny: IMSI catchers are almost certainly intrusive enough to violate both reasonable expectations of privacy and property interests, thus giving rise to Fourth Amendment scrutiny. When used in connection with a residence, the devices provide critical details about the inside of the property that constitutes a search under any framework. While the Supreme Court has held that there is no reasonable expectation of privacy on outgoing phone numbers voluntarily sent to a third party, that analysis likely cannot extend to data that gets redirected and captured by a Hailstorm without the phone-owner’s knowledge or consent.
- General search: There is an argument that any search conducted by an IMSI catcher constitutes a general search, and thus should be categorically barred by the Fourth Amendment. An IMSI catcher indiscriminately gathers all signaling information from a captured phone, seemingly incompatible with a constitutional requirement that surveillance minimize the collection of information unsupported by probable cause. Further, the dragnet functionality conducts this information grab on all devices in a vicinity, including innocent third parties whom the government lacks probable cause to search.
- Inaccurate warrants: When law enforcement does apply for a warrant to use an IMSI catcher, those warrants are very likely inaccurate. Warrant applications, driven by federal policies of non-disclosure, typically either (a) omit the fact that the government intends to use an IMSI catcher, (b) mislead the court by saying the government intends to use less intrusive devices (like a pen register) instead, or (c) fail to provide any information on what the technology is and how it operates. In either scenario, the warrant is predicated on a material omission that deprives a court of its constitutional obligation to balance government interests against intrusions into private rights.
- Invalid warrants: If a warrant accurately states law enforcement’s intended use of an IMSI catcher, it may be facially invalid due to the necessarily general nature of the search. The entire purpose of the warrant requirement is to require law enforcement to state with particularity the area to be searched and the persons or things to be seized. It remains an open question whether warrant particularity requirements can ever be compatible with intrusive dragnet surveillance technologies.
A separate and perhaps more troubling concern is the extreme lengths, only recently uncovered, that the government has gone to in order to keep this technology a secret. The federal government uses extensive non-disclosure agreements to prevent federal, state, and even local law enforcement from disclosing any details on the capabilities and usage of IMSI catchers. There have been a couple instances where judges demanded police to disclose possible use of an IMSI catcher at trial. Prosecutors in these instances have voluntarily dropped the evidence, offered plea bargains without jail time, or voluntarily dismissed the case altogether rather than disclose the device’s usage. Law enforcement agents have also demonstrated a willingness to offer alternative explanations for evidence obtained by an IMSI catcher. In one case where the FBI used a StingRay, for example, a discovered email from a special agent read: “we need to develop independent probable cause for the search warrant . . . FBI does not want to disclose the [redacted] (understandably so).”
IMSI catchers in the courts so far
The first reported decision dealing with an IMSI catcher was in 1995. In re United States, 885 F. Supp. 197 (C.D. Cal. 1995). The court, which had difficulty applying current law to the new surveillance technology, demanded that law enforcement develop stronger safeguards before permitting its use. Since 1995, nation-wide police practices of avoiding disclosure of the devices has largely shielded them from the view of courts. More recent orders from even the most tech-savvy magistrate judges suggest that judicial officers across the country still have little exposure to or understanding of IMSI technology. The lack of exposure and understanding is critical to continuing the law enforcement practice of applying for approval to use a “pen register” device.
Among the courts that have been faced with the question of IMSI catcher use, several—including the 7th Circuit in 2016—have declined to answer questions concerning the devices’ constitutionality. United States v. Patrick, 842 F.3d 540 (7th Cir. 2016). In his dissent, Chief Judge Wood described the avoidance strategies of law enforcement as “bad faith” that could justify suppression, and closed by writing that “it is time for the Sting[R]ay to come out of the shadows, so that it can be subject to the same kind of scrutiny as other mechanisms.”
The 7th Circuit ultimately did revisit the question of Sting[R]ays in Sanchez-Jara in 2018. United States v. Sanchez-Jara, 889 F.3d 418 (7th Cir. 2018). That court rejected the “general search” argument and upheld a warrant that referred generally to “electronic investigative techniques” without specifying the use of IMSI catcher technology. The other federal circuits have yet to reach a decision on the issue.
Andrews v. Balt. City Police Dep’t will almost certainly appear before the 4th Circuit again. While the question in that case deals with whether a pen register application can cover use of a Hailstorm device, deeper questions surrounding the constitutionality of a Hailstorm search underlie every aspect of the litigation. The court will be faced with a police department that has a history of abusing discretion, and that has shielded the courts from its use of IMSI catchers for years, in a moment of increased public scrutiny of police practices and procedures. The 4th Circuit thus has a unique opportunity to create a level of increased accountability for law enforcement, and to change the trajectory of police surveillance strategies for years to come.