We filed an amicus brief in the D.C. Circuit in this criminal appeal, arguing that police need a search warrant to attach a GPS transmitter to a vehicle to track its movements. The trial court refused to suppress the warrantless GPS-generated evidence, relying on a 1983 Supreme Court ruling that the placement of a “beeper” on a vehicle did not require a warrant. We think a GPS device, which can generate a computer data file of its precise location 24/7 without human effort, is far more intrusive and legally distinguishable.

In August 2010, the D.C. Circuit agreed that the defendant’s Fourth Amendment rights were violated. The government successfully sought Supreme Court review, and the ACLU filed an amicus brief in that Court. In January 2012, the Court affirmed, holding that attaching a GPS device to a person’s vehicle without a warrant violates the Fourth Amendment.  

Pro Bono Law Firm(s)

Bryan Cave LLP; Electronic Frontier Foundation

Date filed

October 3, 2011


Amicus Filed