The Massachusetts Supreme Judicial Court has asked for amici help in two pending cases about the Fourth Amendment and GPS surveillance:
In these cases involving co-defendants, the issue presented, among others, is whether an affidavit demonstrated sufficient probable cause in support of an application for a warrant secretly to attach a GPS device to a motor vehicle and to monitor tracking information; whether a passenger has standing to challenge the evidence seized as a result of such monitoring; whether a passenger in a vehicle to which a GPS device is attached is either “seized” or “searched” to the same extent as the driver or the vehicle itself.
On the first question, probable cause, I gather there is a preliminary issue of whether a warrant or probable cause is required to install the GPS device. There is litigation pending on that issue in the federal courts — it’s a difficult issue, in my view — although I don’t know if the issue is also being litigated in the Massachusetts case. Assuming that already has been answered in the affirmative or (unfortunately) has been conceded away, the question becomes what kind of probable cause is deemed sufficient. In the case of a Fourth Amendment search, the ordinary kind of probable cause is probable cause to believe that there is particularly described evidence to be seized inside the particularly described place to be searched. I don’t know how this is supposed to work with a GPS warrant, though. In the case of a GPS search, the government isn’t actually looking to search inside the car for evidence. The car is the place where the GPS is installed, and under Jones it is the “place” where the search occurs. But the information sought is outside of that place, not inside it: The government wants to know where the car will go, not what is inside the car. Perhaps the constitutional standard should be probable cause to believe that the location of the car will be evidence of crime. But if so, I don’t know how you draft the warrant. Is the place to be searched the car, and the evidence to be seized just something abstract like “information about the location of the car”? I’m not sure. That’s not a terrible starting point if you need to cram it into existing doctrine, although it’s not a very clean fit.
On the second question, standing, I think the proper scope of standing depends on what ground(s) the Court uses to conclude that the use of a GPS device was a search. If the SJC is only relying on the Jones trespass rationale, then under Jones I would think the Court needs to consider whether the driver and passenger each individually have sufficient property rights (either as owner or bailee) to challenge the search. See Jones, footnote 2. If the SJC is relying on a reasonable expectation of privacy approach but not the mosaic theory to say that the use of the GPS device is a search — which seems unlikely, but I suppose it’s still theoretically possible — then I would think the framework of Rakas v. Illinois, 439 U.S. 128 (1978), still applies. Finally, if the SJC is relying on the mosaic theory of the Jones concurrences to say that the use of the GPS device is a search, then there are lots of complex questions of standing and remedy that the Court has to answer. In my article, The Mosaic Theory of the Fourth Amendment, 111 Mich. L. Rev. 311 (2012), I flag some of those questions that need to be answered if a court adopts the mosaic approach. An excerpt:
If the exclusionary rule generally applies to mosaic search violations, courts will need to determine its scope. The first challenge is identifying who has standing to challenge a mosaic search. Fourth Amendment rights are personal, and individuals can invoke a remedy only if their own rights have been violated. The Fourth Amendment standing inquiry arises as an application of the reasonable expectation of privacy test. Every defendant must establish that his or her own reasonable expectation of privacy was violated to merit a ruling suppressing the evidence.
Standing raises difficult challenges for the mosaic theory because conduct that creates a mosaic may involve monitoring different people at different times to different degrees. Consider the facts of a recent district court case, United States v. Luna-Santillanes. Three conspirators ran a heroin trafficking enterprise and shared three cars. Different drivers drove the three different cars at different times. Investigators installed GPS devices on all three cars and used the GPS devices to track the movements of the three defendants. The first car was monitored for two months; the second car was monitored for what the court called “a few” days; and the third car was monitored for only two days.
Assuming that the collective monitoring of the three cars constituted a search, who has standing to challenge it? Do all three defendants have standing because their location was monitored as part of a broader mosaic? Or must the standing inquiry look to each individual and consider whether the monitoring of that particular defendant was enough to constitute its own mosaic? Or perhaps the standing inquiry should operate on a car-by-car basis, limiting standing to primary drivers or passengers of particular cars? If the exclusionary rule applies to mosaic searches, courts will need to develop answers to these questions.
[Next] consider whether the exclusionary rule applies to the entire mosaic or only some part of it. To simplify matters, let’s use the prior assumption that seven days of GPS monitoring crosses the line to become a search. If the police monitor a GPS device for ten days, must the entire ten days of monitoring be suppressed? Or should courts only suppress the last three days of monitoring data that occurred after the search line was crossed? Further, imagine the police learn on day two of the ongoing surveillance that the suspect committed a crime. Should the evidence from day two be suppressed because it was part of the mosaic triggered after seven days, even though the collection of that evidence was not a search when it occurred? Or is the evidence from day two an inevitable discovery because it would have been discovered if the monitoring had stopped before the amount of monitoring crossed the mosaic threshold?
A related issue arises when investigators use surveillance to locate targets at a particular moment rather than to develop a picture of their lives over time. Consider a recent case involving a GPS device attached to a car used to transport heroin. Investigators used GPS tracking to find the car. After finding the car, officers conducted a pretextual traffic stop based on a traffic violation, asked for and obtained consent to search the car, and then retrieved two kilograms of heroin inside. Assuming the GPS device was used long enough to cross the threshold of a search, should the heroin be suppressed as a fruit of the poisonous mosaic search? Or does the exclusionary rule not apply because the stop was the product of a short-term use of the GPS device rather than a broader mosaic?