Policy: Warrantless GPS Tracking

On August 25, 2010, The U.S. Court of Appeals for the Ninth Circuit agreed that the DEA did not need a warrant to attach a GPS tracking device to the underside of a Jeep belonging to Juan Pineda-Moreno, an Oregon man suspected of growing marijuana.  The device was attached to the Jeep while it was parked in his driveway, a few feet from his trailer home.  Pineda-Moreno challenged the DEA's actions, arguing that the DEA would need a warrant to invade his privacy.  A three-judge panel argued that Pineda-Moreno's driveway was not private because it was open to strangers, such as delivery people and neighborhood children, who could wander across it uninvited.  And once a GPS device has been planted, the government is free to use it to track people without getting a warrant. (http://www.time.com/time/nation/article/0,8599,2013150,00.html)

Should it be legal to track a vehicle by GPS without obtaining a search warrant?  As an engineer, I feel the need to weigh in on the legality of this situation revolving around possible abuse of new technology.  The wisdom of the federal government's war on drugs is another interesting topic, but I'll leave that for other blogs.

The pro side is simple: using a GPS tracking device to monitor a suspect is no different from the perfectly legal act of waiting outside his home in an unmarked car and following him when he drives around town.  In fact, it's safer because police don't have to drive erratically to follow the suspect in a vehicle.   Police officers have a long history of attaching similar tracking devices to cars, such as radio transmitters ("beepers") that give off an audio signal when officers are close to the transmitter.

The con side is more complex because it requires one to be familiar with the technology, its limits, and its possible misuses.   Many articles have been written about this already and make several good points, including:

• "For starters, the invasion of Pineda-Moreno's driveway was wrong.  The courts have long held that people have a reasonable expectation of privacy in their homes and in the 'curtilage,' a fancy legal term for the area around the home. The government's intrusion on property just a few feet away was clearly in this zone of privacy." And by saying that his driveway was not private because people could wander onto it uninvited, they are allowing police to discriminate against poor and middle-class people who cannot afford to have electric gates, fences and security booths protecting the privacy of their homes.
  
  - Adam Cohen, Lawyer, Former Time Writer
•  Tracking a person's movements with GPS devices is way more invasive than the act of trailing a suspect in public:
  

  "We hold the whole of a person's movements over the course of a month is not actually exposed to the public because the likelihood a stranger would observe all those movements is not just remote, it is essentially nil. It is one thing for a passerby to observe or even to follow someone during a single journey as he goes to the market or returns home from work. It is another thing entirely for that stranger to pick up the scent again the next day and the day after that, week in and week out, dogging his prey until he has identified all the places, people, amusements, and chores that make up that person's hitherto private routine." 

  - Judge Douglas Ginsburg, U.S. Court of Appeals for the District of Columbia Circuit, on a similar warrantless GPS tracking device case
• A GPS tracking device is more invasive than other, legal devices used to track suspects without a warrant (like a radio transmitter):
  

  "Prior Supreme Court cases that allowed the warrantless use of tracking devices were based on the technological limitations of the devices available to at the time. In particular, the devices could only be used to supplement and aid traditional visual surveillance, and were unable to record data on a vehicles movement without human intervention. [….]
  
  "The protections provided by the Fourth Amendment, as the Supreme Court has often recognized, must change to meet new technology. Especially where the cases involve sustained and long-term surveillance of a targeted individual unrelated to any particular criminal action, no reasonable person would expect to be the target of such a massive police surveillance operation. Accordingly, because the use of these devices infringes on a legitimate expectation of privacy, the use of these devices constitutes a search which, absent the present of another exception, requires a warrant."

  - Joshua Engel, Lawyer, Legal Blogger; on warrantless GPS tracking

One point I haven't seen made is that even if the device is attached in a public place and it is legal to track a vehicle's movements by GPS, at some point the vehicle may enter a private residence.  If the police do not remotely shut off or destroy the device at that point, they are monitoring a person's movements on private property.   I think any judge would agree that this would constitute an illegal search.

The GPS device could be turned off remotely if the officers tracking the vehicle saw the vehicle enter a private residence, but it seems unlikely that officers would continuously follow the vehicle around, given that the entire point of the device is that police don't have to follow the suspect in person.

Another way to prevent the device from monitoring private property would be to program the device to automatically stop tracking the vehicle when entering a private residence.   This would require the GPS device to have a map of all private and public areas in a given region; the GPS device would have to differentiate from an (evidently) public driveway and the privacy of a homeowner's garage.  Although online maps are pretty comprehensive, no map like this currently exists (that the public knows of) and even if the government put the effort and money into making such a map, it would be quickly outdated when a resident decides to remodel his property.  In fact, such a map would surely be outdated before it could be completed.

At this point in time, it is impossible to prevent an illegal search once a GPS tracking device is attached to a vehicle (or person).  In fact, if law enforcement officers continue to attach these devices to cars, an illegal search is inevitable.  Because of this and the other reasons listed above, I would conclude that attaching GPS tracking device to a vehicle, person, or his personal belongings without a warrant constitutes a breach in the Fourth Amendment of the Constitution.