The US Supreme Court says drivers have a right to privacy when they are pulled over for petty traffic offenses.
In a unanimous decision on Dec. 8, the high court struck down an Iowa law that authorized the police to physically search any driver and his or her car after issuing a traffic citation.
Such searches are permissible during a traffic stop for the limited purpose of protecting the safety of police officers who need to be able to detect and seize any concealed weapons. They are also permitted to seize and preserve any criminal evidence related to the traffic stop.
At issue in the Iowa case was what happens when the officer discovers evidence of a completely different crime during this limited traffic stop search. Should the evidence be admitted in court or do the actions of the officer constitute an unreasonable search and seizure?
Writing for the court, Chief Justice William Rehnquist drew a critical distinction between a search conducted during a mere traffic stop and a search conducted as part of the arrest of a suspect who is being taken into custody.
The court's decision establishes that drivers who are pulled over for petty traffic offenses retain most of their privacy rights. On the other hand, drivers who are arrested and are on their way to jail have little if any expectation of privacy.
What that means in terms of a police search is that the privacy protections guaranteed in the Constitution do not apply to a driver who is under arrest. If evidence of another crime is found, that evidence can be admitted in court. But if the suspect was not already under arrest at the time of the search, the evidence must be suppressed.
Civil libertarians had warned that if the high court upheld the Iowa law it would have been a blow to drivers' privacy rights and would have encouraged other states to adopt similar laws.
The Iowa case involved a driver, Patrick Knowles, who was pulled over and ticketed for speeding. After issuing a citation, the police officer frisked Mr. Knowles and then searched his car. Under the front seat he found a bag of marijuana.
Knowles was charged and eventually convicted of possession of marijuana. Knowles's lawyer argued that the evidence should be suppressed because the search of the car violated Knowles's Fourth Amendment right to be free from unreasonable searches.