[JURIST] A three-judge panel of the US Court of Appeals for the Sixth Circuit [official website] on Tuesday ruled [decision, PDF] that police did not violate the Fourth Amendment [text] protection against illegal searches when they tracked a suspect’s cell phone using the phone’s global positioning system (GPS) [JURIST news archive] signal. Melvin Skinner was convicted on drug charges after police used the GPS system in his cell phone to locate him while he was transporting large quantities of marijuana. Skinner appealed his conviction, arguing that the police, who did not obtain a warrant for the GPS tracking, violated his Fourth Amendment rights. In his decision, Judge John Rogers said that the tracking of GPS signals is not any more invasive than other recognized police tactics:

If a tool used to transport contraband gives off a signal that can
be tracked for location, certainly the police can track the signal. The law cannot be that a criminal is entitled to rely on the expected untrackability of his tools. Otherwise, dogs could not be used to track a fugitive if the fugitive did not know that the dog hounds had his scent. A getaway car could not be identified and followed based on the license plate number if the driver reasonably thought he had gotten away unseen. The recent nature of cell phone location technology does not change this. If it did, then technology would help criminals but not the police.

The court distinguished its decision from a recent Supreme Court [official website] decision [text, PDF; JURIST report] in United States v. Jones [SCOTUSblog backgrounder], noting that the government did not attach the GPS device, but rather the suspect carried the device with him voluntarily. The court’s decision upheld Skinner’s conviction of three consecutive sentences to 235 months in prison.

Government use of modern technology to monitor and locate citizens has created legal uncertainty recently. Earlier this month, the American Civil Liberties Union announced that their affiliates are sending approximately 375 requests for information in 31 states to reveal how law enforcement uses location data tracking on cell phones [JURIST report], arguing that the warrantless tracking of GPS signals is unconstitutional. In June lawyers for the US Department of Justice defended the warrantless use of GPS devices [JURIST report] on suspects’ vehicles despite the Supreme Court ruling in Jones declaring GPS tracking to be a “search” under the Fourth Amendment. The Supreme Court concluded in Jones that the government’s attachment of a GPS device to a vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a search under the Fourth Amendment. Also in January, the Supreme Court of California ruled that law enforcement officers can legally search text messages [JURIST report] on a suspect’s cell phone without a warrant incident to a lawful custodial arrest.