The Supreme Court has ruled that an anonymous tip can be sufficient to justify a decision by police to pull a car over on suspicion of reckless or drunken driving.

The justices voted 5-4 to uphold a traffic stop in northern California in which officers subsequently found marijuana in the vehicle. The officers themselves did not see any evidence of reckless driving.

Justice Clarence Thomas said the tip phoned in to 911 that a Ford pickup truck had run the caller off the road was sufficiently reliable to allow for the traffic stop without violating the driver’s constitutional rights.

Justice Clarence Thomas delivered the opinion of the Court in Prado Navarette v. California, No. 12-9490.  Justice Antonin Scalia issued a dissenting opinion, in which Justices Ruth Bader Ginsburg, Sonia Sotomayor, and Elena Kagan joined.

You can access the oral argument via this link.