The US Supreme Court will weigh-in on an important privacy issue for the digital age: whether the police need a warrant before using a global positioning system device to track a suspect's movements.
The justices said Monday they will hear the Obama administration's appeal of a court ruling that favoured a criminal defendant. The federal appeals court in Washington overturned a criminal conviction because the police had no warrant for the GPS device they secretly installed on a man's car.
Other appeals courts have ruled that search warrants aren't necessary for GPS tracking.
The US Justice Department argued that warrantless use of GPS devices does not violate the Fourth Amendment's ban on unreasonable searches. It also said prompt resolution of the divergent court opinions is critically important to law enforcement.
A three-judge panel of Democratic and Republican appointees unanimously threw out the conviction and life sentence of Antoine Jones of Washington, D.C., a nightclub owner convicted of operating a cocaine distribution ring.
Police put the GPS device on Jones' Jeep and tracked his movements for a month. The judges said the prolonged surveillance was a factor in their decision.
The high court directed both sides to address whether a warrant or consent is needed, regardless of how long the surveillance might last.
The US government has argued that using a GPS device is no different from a beeper authorities used, with the high court's blessing in 1983, to help track a suspect to his drug lab. The court said then that people on public roads have no reasonable expectation of privacy.
The US Justice Department said GPS devices are especially useful in early stages of an investigation, when they can eliminate the use of time-consuming stakeouts as officers seek to gather evidence.
Four other appellate judges in Washington said the entire appeals court should have heard the case, faulting their colleagues for the ruling in favour of Jones.
In another case, from California, a three-judge panel in San Francisco upheld the use of a GPS device without a warrant, saying it was no different from having officers tail a suspect.
That decision provoked a blistering dissent from Judge Alex Kozinski, who said the court handed "the government the power to track the movements of every one of us, every day of our lives."