A recent U.S. Supreme Court ruling will impact criminal defense in southern Illinois and elsewhere in the United States. The facts of the case involved police use of a GPS tracking device and whether the use of the device without a warrant violated the Fourth Amendment's protection from unreasonable search and seizure. The U.S. Supreme Court unanimously ruled today that police must obtain a search warrant before using GPS to track criminal suspects.

The case dates back to 2005 when police in the Washington D.C. area secretly attached a GPS device to a suspect's vehicle while it was parked in a public parking lot. The owner of the vehicle was a nightclub owner suspected of trafficking cocaine. Officers tracked the suspect's vehicle for over four weeks and used the evidence to initially convict the nightclub owner on conspiracy to distribute cocaine. The Supreme Court's decision affirms the reversal of the conviction.

The GPS device was used by police to help establish a connection between the suspect and a house used to store money and drugs. Justice Antonin Scalia, who wrote the main opinion, said the installation of the GPS device by police and the monitoring of the vehicle through the use of the device qualified as a search and therefore a warrant was required.

Scalia considered the installation of the GPS device on the vehicle without a warrant as a trespass and therefore illegal. All of the justices agreed with the conclusion of the ruling, but two justices wrote concluding opinions with different legal analysis. One concurring opinion, written by Justice Alito, focused on the suspect's expectation of privacy and the affect the month-long surveillance had on that expectation.

Source: The Associated Press, "US high court: warrant needed for GPS tracking," Jesse H. Holland, Jan. 23, 2012