A recent AP article reports on the growing trend of stashing miniature GPS devices inside items that are likely to be stolen and then tracking those items after the theft occurs. The article describes a string of armed robberies on Long Island in which the perpetrator stole cash from gas stations and convenience stores. Police investigators then slipped a miniature GPS device into a stack of cash that the perpetrator was likely to steal, and then–once the money was in fact stolen–tracked the perpetrator for a number of days until arresting him. (The article does not say how the police were able to predict where the robber was going to strike next; presumably they provided these miniature devices to a number of prospective theft victims). This law enforcement tool has been used in different ways for many years: the article correctly notes that police use a car’s built-in GPS tracking system to trace the car after it has been stolen, and also notes that pharmacists frequently have a pill bottle pre-loaded with a GPS tracker to give to a robber who steals drugs. In a new twist, police officers who are engaged in a high-speed car chase are now shooting miniature GPS devices out of a special air cannon mounted in the front of the police car. Once the GPS device sticks to the car, the police can call of the dangerous chase and simply track the criminal to his final destination.
On its face, thes appears to be a valuable law enforcement tool that can help police solve crimes. Yet the AP news story’s headline delivers a warning: “Hidden GPS devices to track suspects raise legal concerns.” An ACLU spokesperson argues that “As a baseline, I don’t think people should be tracked with GPS without a warrant,” echoing the theme of the 2012 Supreme Court case United States v. Jones, in which a plurality of the Court held that using a GPS device to track an individual over public roads for four weeks violated that individual’s reasonable expectation of privacy.
These concerns seem alarmist, at best. Even the concurring Justices in Jones did not imply that any tracking with a GPS required a warrant–they were only concerned with tracking over an extended period of time, which would give law enforcement a “mosaic” picture of someone’s life. And here we are talking about GPS devices which are attached to stolen property–property, in other words, in which the owner has no reasonable expectation of privacy. This remains true even if the police decide to continue the tracking for a few days or weeks after the theft to see if the stolen property leads them to other contraband or other criminals. The only feasible argument against this use of GPS tracking would be that the actual criminal might transfer the stolen property–and with it, the GPS device–to an innocent third party, who would then be tracked by the police. Even then, of course, the GPS device would only show the location of the stolen goods, which the police are entitled to recover even from innocent third parties.
It is certainly important to be vigilant as law enforcement officers develop and employ new technologies in their investigations–we have to ensure that there is the proper balance between liberty and security. But some uses of new technologies increase security without infringing on our liberty or privacy rights in any significant way.