WASHINGTON—The Supreme Court has upheld the authority of police officers to stop cars and question their drivers based on an anonymous tip to a hot line.

In a 5-4 decision written by Justice Clarence Thomas, the justices ruled that such stops do not amount to an unreasonable search or seizure, even if the arresting officer did not observe the vehicle speeding or swaying while driving down the highway.

The decision affirmed a ruling of the California courts.

In August 2008, a 911 dispatch team in Mendocino County received a report that a pickup truck had run another vehicle off the road. The caller did not identify himself, but the report included a detailed description of the truck, including its license plate number.


Responding to the call, an officer saw a truck which fit the description. After stopping it, he found 30 pounds of marijuana in the truck bed. Two men, Lorenzo and Jose Navarette, were arrested and later convicted of trafficking marijuana.

They appealed and argued the stop and subsequent search had violated their rights under the 4th Amendment, which prohibits “unreasonable” searches and seizures.

In the past, the court had said police officers may not rely on an anonymous tip to stop and search a pedestrian. In that case, the justices had worried that anonymous callers could unfairly target people for embarrassing searches.

But in Tuesday’s decision in Navarette vs. California, the court majority agreed that police have “reasonable suspicion” to stop a vehicle if they receive a report that it was speeding, swerving, or, as in this case, forcing another car off the road.


The case split the court along the usual ideological lines, but with two significant switches. Justice Stephen Breyer, usually part of the court’s liberal minority, joined Thomas’ majority. Justice Antonin Scalia, who sides with Thomas in the vast majority of cases, dissented.

That same lineup in summer 2013 decided an important case about DNA testing of arrestees, with Breyer in the majority and Scalia in dissent.

David.Savage@latimes.com

Twitter: @DavidGSavage