Police powers

A unanimous Supreme Court established important Fourth Amendment limits on police powers in a high-tech era.

The justices said that police in the nation’s capital went too far in putting a global positioning system tracking device on the vehicle of a suspected drug dealer to monitor his movements 24 hours a day for almost a month without a warrant. With its ruling, the court overturned the conviction of Antoine Jones for conspiring to sell cocaine based on evidence gathered with the GPS device.

The high court rejected the government’s defense that GPS tracking that can follow the travels of a vehicle uninterrupted was comparable to the traditional methods of police surveillance. However, the nine justices divided in their rationale for putting limits on the use of electronic devices in an era when police do not have to go onto property or actually enter a home to obtain information.

Writing for five members, Justice Antonin Scalia said that the “government’s installation of a GPS device on a target’s vehicle, and its use of that device to monitor the vehicle’s movements, constituted a ‘search’” under the Fourth Amendment.

By placing the device, he said, the government “physically occupied private property” and constituted a “physical intrusion” requiring a search warrant.

The remaining four members based their decision on broader concerns for personal privacy in a high-tech world that records “mundane tasks” with video surveillance in public places, automated toll-booth collection systems and location data that can be gathered from cell phone use or in-vehicle technology.

Justice Sonia Sotomayor said that new technology can “make available at a relatively low cost such a substantial quantum of intimate information about any person who the government, in its unfettered discretion, chooses to track.” The government, she wrote, cannot be free to use “a tool so amenable to misuse.”

With the court’s decision, Americans regained some presumption of privacy, even in public.