Prado Navarette v. California
The Supreme Court ruled that police acted lawfully when they stopped a truck based on an anonymous 911 caller's report that it had run her off the road, finding the tip reliable enough and suggestive enough of drunk driving to justify the stop.
The decision extends how much weight officers can give anonymous tips about erratic driving, even without personally witnessing bad driving themselves, a point four dissenting justices warned could erode Fourth Amendment protections for ordinary drivers.
How it got here: A trial court denied the brothers' motion to suppress the evidence; they pleaded guilty; the California Court of Appeal affirmed; the Supreme Court agreed to hear their appeal.
The Case in Depth
What happened
A 911 caller reported that a silver Ford F-150 pickup truck had run her off a California highway. Police broadcast the description, and an officer located and stopped the matching truck about 18 minutes later. Smelling marijuana, officers searched the truck bed and found 30 pounds of marijuana, leading to the arrest of the truck's driver and passenger, two brothers.
The question before the Court
Could police pull over a truck based only on an anonymous 911 caller's report that it had run her off the road?
The Court's answer
Yes — the Court ruled that the officer had reasonable suspicion to stop the truck. The anonymous 911 caller claimed to have personally witnessed the truck run her off the road, made the call shortly after it happened, and used the traceable 911 system, all of which supported the tip's reliability. Running another car off the road also resembled the kind of impaired driving associated with drunk driving.
The Court added that the officer's five minutes of otherwise unremarkable observation did not erase that suspicion, since officers don't have to watch a suspect drive for an extended period once reasonable suspicion has already formed. Because the tip was reliable and suggested an ongoing crime, the stop — and the marijuana search that followed it — was constitutional.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Drivers can now be pulled over based solely on a single anonymous phone tip describing one incident of possibly dangerous driving, without officers observing any bad driving themselves. Police departments gain more latitude to act on 911 tips about erratic driving, while civil liberties groups worry ordinary drivers face a greater risk of being stopped on unverified accusations.
What changes now
Because this is a final merits decision, the case itself is resolved: the brothers' convictions stand, and the marijuana evidence remains admissible. Going forward, the ruling gives law enforcement and lower courts a framework for evaluating anonymous 911 tips about erratic driving, though how it applies will continue to be tested case by case with different facts.
What this does not decide
The Court explicitly did not decide whether or how a stop could be justified to investigate driving that had already stopped rather than an ongoing crime, and it did not hold that anonymous tips are reliable as a general rule — only that this particular tip's specific features supported reliability here.
Concurrences and dissents
Dissent — Justice Scalia
Justice Scalia argued the anonymous tipster's account was uncorroborated and unreliable, rejecting the majority's reasoning about eyewitness knowledge, timing, and 911 traceability as making the tip trustworthy. He also argued that even if the tip were credited, a single episode of running someone off the road does not show ongoing drunk driving, especially since the officers followed the truck for five minutes and saw nothing suspicious. He would have reversed and found the stop unconstitutional.
How the Court got there
The legal reasoning, step by step
- The Court applied the reasonable-suspicion standard for brief investigative stops, which asks whether an officer has a particularized and objective basis for suspecting a specific person of criminal activity, judged under the totality of the circumstances.
- It applied that standard to anonymous tips specifically, noting that while a bare anonymous tip alone rarely shows enough reliability, it can under the right circumstances, as prior cases about predicting a suspect's future movements and detailed firsthand accounts had shown.
- The Court found the caller's claim to have personally witnessed being run off the road demonstrated firsthand knowledge, and the short time between the incident and the call left little opportunity to fabricate the story, both supporting reliability.
- The Court treated the caller's use of the 911 system itself as a further reliability marker, reasoning that technological and legal safeguards tracing 911 calls would make a false tipster think twice before lying.
- Having found the tip reliable, the Court concluded that running another car off the road is the kind of erratic behavior associated with drunk driving, and that reasonable suspicion does not require ruling out innocent explanations, so the tip created reasonable suspicion of an ongoing crime.
- The Court held that five minutes of unremarkable driving observed afterward did not erase that suspicion, because officers are not required to watch a suspect drive for an extended period before acting on reasonable suspicion already formed.
Doctrinal impact
Cases affected by this decision
Reaffirms Alabama v. White (496 U. S. 325)
The Court relies on White's framework for when anonymous tips can create reasonable suspicion.
Distinguishes Florida v. J. L. (529 U. S. 266)
The Court says this tip was more reliable than the bare-bones tip found insufficient in J. L.