On April 22, 2014, the United States Supreme Court affirmed the judgment of the California Court of Appeal, in Navarette v. California, which held that an anonymous tip can, under certain circumstances, provide an officer with reasonable suspicion to make an investigative stop.

Appellants/Defendants Lorenzo and Jose Navarette asserted that the California Highway Patrol’s reliance on an anonymous tip to initiate a DUI investigation violated their Fourth Amendment Rights under the United States Constitution. The Supreme Court disagreed.

The Court held that, “the indicia of reliability [of the tip was] sufficient to provide the officer with reasonable suspicion that the driver of the reported vehicle had run another vehicle off the road. That made it reasonable under the circumstances for the officer to execute a traffic stop.”


On August 23, 2008, a Mendocino County dispatch center for the Highway Patrol received a call that a silver Ford F-150 had forced a woman off of the road. The caller provided the direction that the Ford F-150 was traveling, the location of the incident and she also provided the license plate number of the truck. Based upon the information that was provided to dispatch, the CHP made contact with a Ford F-150 with the same license plate number as the truck that forced the woman off of the road. Upon conducting a DUI investigation, the CHP officer discovered 30 pounds of marijuana in the truck. Based upon the possession of the marijuana, Defendants Lorenzo Navarette and Jose Navarette were arrested.

After the arrest, the Defendants challenged the lawfulness of the stop by filing a motion to suppress which was denied by the trial court. Consequently, they pled guilty to the possession of the marijuana and received 90 days in jail and probation.

The Defendants appealed the denial of the suppression motion to the California Court of Appeal. The Court of Appeal affirmed the trial court’s decision. The Defendant’s attempted to appeal to the California Supreme Court, but the Supreme Court denied their request for review. However, the United States Supreme Court agreed to hear their appeal.


The U.S. Supreme Court divided the case into two questions. The first question was “whether the 911 call was sufficiently reliable to credit the allegation that the petitioners’ truck ‘ran the [caller] off the roadway?’” In addressing this question, the court noted that by providing specific details about the truck, “the caller necessarily claimed eyewitness knowledge of the alleged dangerous driving.” The Court went on to note that, similar to the hearsay exceptions, the timing of the call in relation to the accident provided additional credibility to the tip because the caller would not have had time to concoct a story prior to calling 911.

Another factor that weighed in favor of believing that the tipster was being truthful is that providing false information to the dispatcher could have resulted in criminal prosecution under the California Penal Code. See, Penal Code §§ 653x, 148.3, and 148.5. The Court also observed that dispatch is equipped with caller I.D.  Justice Thomas noted “[g]iven the foregoing technological and regulatory developments… a reasonable officer could conclude that a false tipster would think twice before using such a system.”

The next question that the Court addressed was “whether the 911 caller’s report of being run off the roadway created reasonable suspicion of an ongoing crime such as drunk driving, as opposed to an isolated episode of past recklessness?” In answering this question, the Court noted that “common sense” allows recognition that “certain driving behaviors as sound indicia of drunk driving.”

The Court noted that “weaving all over the roadway,” “crossing over the center line,” “almost causing several head-on collisions,” and “weaving back and forth” are common indicia of drunk driving. While the Court conceded that “not all traffic infractions imply intoxication,” the Court emphasized that “a reliable tip alleging the dangerous behaviors … generally would justify a traffic stop on suspicion of drunk driving.”  The Court stated that, “the 911 caller in this case reported more than a minor traffic infraction and more than a conclusory allegation of drunk or reckless driving.”

The Court emphasized that the conduct described to the dispatcher “bears too great a resemblance to paradigmatic manifestations of drunk driving to be dismissed as an isolated example of recklessness.”

The Court also rejected the argument that the officer would have to observe additional bad driving upon making contact with the car that was the subject of the tip. The court noted “it is hardly surprising that the appearance of a marked police car would inspire more careful driving for a time.”

Further, the Court pointed out that “the reasonableness of the officer’s decision to stop a suspect does not turn on the availability of less intrusive investigatory techniques.”  The Court refused to depart from the settled rule that officers do not have to use “less intrusive investigatory technique” because “allowing a drunk driver a second chance for dangerous conduct could have disastrous consequences.”

The Court did acknowledge that “this is a close case.” However, it held that “(u)nder the totality of the circumstances, we find the indicia of reliability in this case sufficient to provide the officer with reasonable suspicion that the driver of the reported vehicle had run another vehicle off the road. That made it reasonable under the circumstances for the officer to execute a traffic stop.”

Dissenting Opinion

It is interesting to note that the four justices who dissented include Justice Scalia, possibly the most conservative member of the Court, along with Justices Ginsburg, Sotomayor, and Kagen, the liberal wing of the Court.

Nonetheless, the dissenting justices voice great concern about accepting an anonymous tip as the basis for justifying an investigative stop. In the instant case, the caller did not state that the driver was drunk, but that was the reasoning given by the officers for the stop and investigation.

“Bear in mind that [the DUI] is the only basis for the stop that has been asserted in this litigation.   The stop required suspicion of an ongoing crime, not merely suspicion of having run someone off the road earlier.”

“All the malevolent 911 caller need do is assert a traffic violation, and the targeted car will be stopped, forcibly if necessary, by the police. If the driver turns out not to be drunk (which will almost always be the case), the caller need fear no consequences, even if 911 knows his identity. After all [in this hypothetical], he never alleged drunkenness, but merely called in a traffic violation . . . .”


The short answer on “how this affects your agency” is – not much. The holding of the case affirmed the decision of the California Supreme Court in People v. Wells, 28 Cal. 4th 1078 (2006), which held that “an anonymous and uncorroborated tip regarding a possibly intoxicated highway driver” provides reasonable suspicion to justify a stop.

As such, your agency will continue to be allowed to rely on anonymous tips as the basis for initiating DUI investigations.  With that said, it must be emphasized that this case may allow investigative stops for “crimes” other than a suspected DUI.

As such, the best practice is to ensure that the stop can survive judicial review. It will be necessary to make sure that the tip provides as much detail as possible regarding the vehicle (i.e. the license plate number, model, color, number of passengers, etc.) and the alleged criminal conduct.

This decision does not grant “carte blanche” to conduct investigative stops on the basis of an anonymous tip alone – it must provide reasonable suspicion, as the majority found in this situation.

As with all legal issues, it is imperative to confer with your agency’s designated attorney for advice and guidance. However, if you wish to discuss this case in greater detail, please feel free to contact Martin Mayer or Jamaar Boyd-Weatherby at (714) 446 – 1400 or via email atmjm@jones-mayer.com and jbw@jones-mayer.com.

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