By Brad Leneis, J.D. Candidate

United States v. Jones, No. 10-1259 (appeal docketed Apr. 15, 2011) promises to be one of the most important cases on the Supreme Court docket this term. In Jones, the Court will examine the Fourth Amendment implications of technology-enhanced tracking by law enforcement for the first time since United States v. Karo, 468 U.S. 705 (1984)—a case decided shortly after the release of the first Macintosh PC. Developments in tracking technology over the past 27 years have kept pace with developments in personal computers: while Karoinvolved the use of a primitive radio transmitter that only provided its location relative to a matching receiver, the GPS device in Jones pinpoints its absolute location to within ten feet by communicating with orbiting satellites. See Department of Defense, Global Positioning Standard Positioning Service Performance Standard, v (4th ed. 2008) (http://www.pnt.gov/public/docs/2008/spsps2008.pdf). Monitoring the movements of a suspect’s car via GPS has become a commonplace law enforcement technique, and courts are granting increasing leeway to attach a GPS unit to a car parked in a suspect’s driveway, even when the car is parked within the curtilage of the home.  See United States v. Pineda-Moreno, 591 F.3d 1212, 1214–15 (9th Cir. 2010),reh’g en banc denied, 617 F.3d 1120 (9th Cir. 2010).

Jones was initially convicted of conspiracy to distribute and to possess five or more kilograms of cocaine. United States v. Maynard, 615 F.3d 544, 548 (D.C. Cir. 2010), reh’g en banc denied, 625 F.3d 766 (D.C. Cir. 2010). As part of their investigation of Jones and his co-conspirators (among them Maynard, for whom the case was styled in the D.C. Circuit), law enforcement agents planted a GPS unit on his car and tracked his movements for thirty days. Id. at 555. Data from the GPS unit played a critical role in the government’s case against Jones: no drugs were ever found in his possession, but the GPS data showed that he repeatedly visited a house where agents uncovered almost a hundred kilograms of cocaine and $850,000 in cash. Id. at 567. In combination with records of Jones’ phone calls to the house, prosecutors used the GPS data to “paint a picture that made credible the allegation that he was involved in drug trafficking.” Id. 568.

The D.C. Circuit reversed, holding that the continuous, warrantless use of the GPS unit to track Jones’ movements over a thirty-day period violated the Fourth Amendment.  Id. at 563–64. Writing for the panel, Judge Ginsburg concluded that the use of a GPS unit to monitor all of Jones’ movements while driving was unreasonable because it “reveal[ed] an intimate picture of [his] life that he expects no one to have.” Id. at 563. Although Jones had no reasonable expectation of privacy in any single trip on a public road, the “whole of one’s movements over the course of a month . . . reveals far more than the individual movements” that comprise it. Id.at 562. Under this “mosaic theory,” id. at 562, prolonged GPS surveillance is unreasonable because it enables law enforcement to do something that a reasonable person would not expect anyone to do––“monitor and retain a record of every time [one] drives his car.” Id. at 563.

The mosaic theory represents a novel shift in Fourth Amendment tracking jurisprudence. In Karo and its companion case, United States v. Knotts, 460 U.S. 276 (1983), the Supreme Court’s concern with the first generation of tracking devices revolved around the devices’ capacity to reveal information about the interior of the home that would otherwise have been hidden. In both Karo and Knotts, law enforcement agents placed a beeper equipped with a radio transmitter inside a canister of chemicals that could be used to manufacture illegal drugs. See Karo, 468 U.S. at 708; Knotts, 460 U.S. at 277. In Knotts, agents used the beeper to help track the canister after its purchase to the defendant’s secluded cabin, where he was making methamphetamines. 460 U.S. at 278–79. The can with the beeper ended up outside the cabin under a barrel. Id. at 279.  The Court held that the use of the beeper did not violate the Fourth Amendment, because the beeper simply “augment[ed]” the agents’ ability to monitor the canister’s travel along public roadways, where a person has “no reasonable expectation of privacy in his movements from one place to another.” Id. at 282–83.

In Karo, agents similarly used the beeper to help track the canister from the point of purchase to the defendant’s house; but the canister was subsequently moved, unobserved, to another house, and another, and then to a storage locker. 469 U.S. at 708.  Agents were only able to follow the can by relying on the beeper’s transmissions from inside each location. Id. The Court held that using the beeper to obtain this information violated the Fourth Amendment, because it “reveal[ed] a critical fact about the interior of the premises” that could not have been “visually verified” from outside. Id. at 715. Taken together, Knotts and Karo established a ground rule for the use of tracking devices that turned on the location of the tracking device when it obtains information, rather than the nature of the information obtained. 

In a dissent from the denial of rehearing en banc, Chief Judge Sentelle highlighted the central importance of the device’s location to the outcome of the Fourth Amendment analysis. See Maynard, 625 F.3d 766, 769 (D.C. Cir. 2010). His analysis followed the form of a mathematical proof: under Knotts and Karo, he reasoned, the “reasonable expectation of privacy as to a person’s movements on the highway is . . . zero.” Id. Information gathered about such movements can never violate a person’s reasonable expectation of privacy, regardless of its quantity or nature, because “the sum of an infinite number of zero-value parts is also zero.” Id. In the government’s brief for the Court in Jones, the Solicitor General adopted Chief Judge Sentelle’s argument, stating that “[t]he reasonable expectation of privacy in activities exposed to public view does not depend on the total quantity of information collected,” Brief for Petitioner at 27, United States v. Jones, No. 10-1259 (Aug. 11, 2011), and quoted his dissent at length, id. at 29.

Jones, then, turns on the question of the direction in which permission flows from the Fourth Amendment. Under Judge Ginsburg’s mosaic theory, the Fourth Amendment denies the government permission to take actions that a reasonable person would not expect anyone to take. Under Chief Judge Sentelle’s reasoning, the Fourth Amendment denies the citizen permission to expect privacy in her accumulated movements on public streets, regardless of how thoroughly law enforcement monitors and documents those movements. 

The Court hears argument in Jones on November 8, 2011.