A Delaware superior court judge took a stand last month against the warrantless police use of GPS devices to record the movements of drivers. Judge Jan R. Jurden issued her ruling in the case of Michael D. Holden who was arrested on drug charges in February 2010 as a result of information obtained from a tracking device.

The Drug Enforcement Administration took interest in Holden after receiving a tip from an informant. Agents decided on their own authority to attach a battery-powered tracker to Holden's white 1998 Lexus while it was parked on the street. Agents did not bother asking a judge for a warrant. Holden's Lexus was tracked 24 hours a day for three weeks without any incriminating result. Then a new tip suggested Holden would be picking up marijuana on February 24. Agents followed Holden to a house in New Jersey where luggage was exchanged with the driver of another vehicle. Agents provided a live update on the position of the Lexus and ordered the Delaware River and Bay Authority police to stop and search Holden. He found to be carrying marijuana.

Holden argued that there was no probable cause for the traffic stop or a finding of cause before his car was subjected to constant surveillance. Prosecutors countered that citizens have no expectation of privacy on a highway, so there are no restrictions on the ability of officers to track any member of the public. Judge Jurden resolved the question under the provisions of Delaware's state constitution.

"That all warrants without oath to search suspected places or to seize any person or his property, are grievous and oppressive; and all general warrants to search suspected places, or to apprehend all persons suspected, without naming or describing the place or any person special, are illegal and ought not be granted," section 17 of the constitution states.

Delaware's legislature went further by specifically making it a crime to "knowingly install an electronic or mechanical location tracking device in or on a motor vehicle without the consent of the registered owner," excepting the lawful use by law enforcement. Jurden questioned whether the use without a warrant was lawful in this case.

"Jurisdictions throughout the United States have found that citizens have a reasonable expectation of privacy in their prolonged travels on public thoroughfares," Jurden wrote in her decision. "Courts have used a 'public exposure rationale,' to hold that privacy interests are not implicated with regard to acts exposed to the public. However, the monitoring of a single trip is far different than constant prolonged surveillance."

Jurden argued that there was a fundamental difference between a police officer bumping into someone on the street and using technology to track hundreds of suspects with the click of a mouse.

'It takes little to imagine what constant and prolonged surveillance could expose about someone's life even if they are not participating in any criminal activity," Jurden wrote. "Even if there is no reasonable expectation to be free from casual encounters by others in the public sphere, society reasonably expects to be free from constant police scrutiny. Everyone understands there is a possibility that on any one occasion or even multiple occasions, they may be observed by a member of the public or possibly law enforcement, but there is not such an expectation that an omnipresent force is watching your every move... No one should be subject to such scrutiny by police without probable cause."

Absent exigent circumstances, Jurden found that use of GPS tracking for a prolonged time without a warrant and probable cause violated the state constitution. The court granted Holden's motion to suppress the evidence obtained as a result of the tracking device.

A copy of the decision is available in a 190k PDF file at the source link below.