By David Daggett

The Supreme Court of the United States recently decided the case of Navarette v. California, 134 S.Ct. 1683 (2014), and in the process, seemed to hand law enforcement a new arrow to put in its quiver. How far it will be taken remains to be seen. While police and prosecutors shouldn’t look a gift horse in the mouth, it shouldn’t be blindly argued in all cases involving an anonymous tip either. Anonymous tips still require some sort of fundamental basis for reliability.

The saga of the brothers Navarette begins in Mendocino County, California on August 23, 2008. Mendocino County is located north of the greater San Francisco Bay area and west of the Central Valley. It is noted for its distinctive Pacific Ocean coastline, Redwood forests, wine production, microbrews, and liberal views about the use of cannabis and support for its legalization. Coincidentally, according to its Wikipedia page, is is estimated that roughly one-third of Mendocino County’s economy is based on the cultivation of marijuana. Apparently our protagonists were fledgling entrepreneurs engaged in bolstering that economy.

At approximately 3:42 in the afternoon, a dispatch was received by the California Highway Patrol from a recorded 911 call. The Mendocino County Dispatch team then broadcast the following information to CHP officers at 3:47 p.m.: “Showing southbound Highway 1 at mile marker 88, Silver Ford 150 pickup. Plate of 8-David-94925. Ran the reporting party off the road and was last seen approximately five minutes ago.”

At 4:00 p.m. a CHP officer saw the vehicle at mile marker 69 and followed it for about five minutes and, after failing to notice any further violations, nevertheless pulled it over at 4:05 p.m. Another officer arrived on the scene and as the two approached the truck, they noticed the smell of marijuana. A search of the truck bed revealed 30 pounds of ganja.

The Navarette brothers – Lorenzo and Jose – were arrested. Moving to suppress the evidence, they argued that the traffic stop violated the Fourth Amendment because the officer lacked reasonable articulable suspicion of criminal activity. Two lower courts disagreed and the California Court of Appeals affirmed the conviction, concluding that the officer did have reasonable suspicion to conduct a stop. The California appellate court reasoned that the content of the tip indicated that it came from an eyewitness victim of reckless driving and that the officer’s corroboration of the truck’s description, location and direction established that the tip was enough to justify a traffic stop. The California Court of Appeals also concluded that the caller reported driving that was sufficiently dangerous to merit an investigative stop without waiting for the officer to observe additional reckless driving himself. The California Supreme Court denied review and the Supreme Court granted certiorari.

The SCOTUS (Justice Thomas) held that the Fourth Amendment permits brief investigatory stops – such as the traffic stop in a case such as this – when a law enforcement officer has “a particularized and objective basis for suspecting the particular person stopped of criminal activity.” The reasonable suspicion necessary to justify such a stop “is dependent upon both the content of information possessed by the police and its degree of reliability.” Alabama v. White, 496 U.S. 325, 330 (1990). The Court determined that the standard takes into account “the totality of the circumstances – the whole picture” and although a mere “hunch” does not create reasonable suspicion, the level of suspicion the reasonable suspicion standard requires is considerably less than that required for probable cause. Probable cause requires that it is more likely than not that a particular crime was committed and that this person committed the crime (preponderance of the evidence).

The Court, in a tight 5-4 decision, determined that these principles apply with full force to investigative stops based on information from anonymous tips. While acknowledging that an anonymous tip alone seldom demonstrates an informant’s basis of knowledge or veracity, under appropriate circumstances, an anonymous tip can demonstrate “sufficient indicia of reliability to provide reasonable suspicion to make an investigatory stop.” The Court stated that Alabama v. White, 496 U.S. 325 (1990) and Florida v. J.L., 529 U.S. 266 (2000) provided useful guides.

In Alabama v. White, an anonymous tipster told the police that a woman would drive from a particular apartment building to a particular motel in a brown Plymouth station wagon (a brown, Plymouth station wagon! Volare? Reliant?) with a broken right tail light. The tipster further stated that the woman would be transporting cocaine. After confirming the details, the officer stopped the station wagon as it neared the motel and found cocaine in the vehicle. The Court determined that the officer’s corroboration of certain details made the anonymous tip sufficiently reliable to create reasonable suspicion of criminal activity and that by accurately predicting future behavior, the tipster demonstrated “a special familiarity with the

[defendant’s] affairs” which in turn implied that the tipster “had access to reliable information about that individual’s illegal activities.”

In Florida v. J.L., the Court determined that no reasonable suspicion arose from a minimal tip that a young black male in a plaid shirt standing at a bus stop was carrying a gun. The tipster did not explain how he knew about the gun, nor did he suggest that he had any special familiarity with the young man or his affairs. As a result, police had no basis for believing “that the tipster had knowledge of concealed criminal activity.” Furthermore, the tip included no predictions of future behavior that could be corroborated to assess the tipster’s credibility and the Court concluded that the tip was insufficient to justify a stop and frisk.

Was the 911 call sufficiently reliable to credit the allegations that Navarette’s truck ran the caller off the road?

The Court determined that one of the key questions to be answered was, even had the 911 call been anonymous*, did it bear adequate indicia of reliability for the officer to credit the caller’s account?

The Court concluded that the call did indeed bear adequate indicia of reliability and that the officer was justified in proceeding from the premise that the truck had run the caller’s car off the highway. The Court placed great weight on the fact that the caller was very specific – a silver Ford F-150, license plate number 8D94925- and that the caller necessarily claimed eyewitness knowledge of the alleged dangerous driving. That basis of knowledge lent significant support to the tip’s reliability. The Court stated that the driver’s claim that another vehicle ran her off the road, necessarily implies that the informant knows the other car was driven dangerously.

The Court also placed importance on the fact the 911 caller was apparently telling the truth in that police confirmed the truck’s location near mile marker 69 (appx. 19 miles south of mile marker 88) at 4:00 p.m. (roughly 18 minutes after the call). This timeline of events suggested to Justice Thomas that the caller reported the incident soon after she had been run off the road and that that sort of contemporaneous report has long been treated as especially reliable as a “present sense impression” or “excited utterance” exceptions to the hearsay rules.

Additionally, Justice Thomas noted that another indicator of veracity is the caller’s use of the 911 emergency system. It stated that 911 calls have some features that allow for identifying and tracing callers and that provides some safeguards against making false reports with impunity. A reasonable officer could conclude that a false tipster would think twice before using such a system and could in fact be charged with making a false police report.

Notwithstanding these factors, the Court held that even a reliable tip will justify an investigative stop only if it creates reasonable suspicion that “criminal activity may be afoot,” a la Terry, and therefore the Court had to determine 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. The Court concluded that the behavior alleged by the 911 caller, “viewed from the standpoint of an objectively reasonable police officer, amounts to reasonable suspicion of drunk driving” and that therefore the stop was proper.

The Court determined that under the commonsense approach, a court can appropriately recognize certain driving behaviors as sound indicia of drunk driving. The Court noted “weaving all over the roadway”; crossing over the center line on a highway and almost causing several head on collisions”; “driving all over the road” and “weaving back and forth”; and “driving in the median” as examples of erratic behaviors that are strongly correlated with drunk driving. A reliable tip alleging the dangerous behaviors previously mentioned would generally justify a traffic stop on suspicion of drunk driving.

Justice Thomas opined that the 911 caller in Navarette reported more than a minor traffic infraction and more than a conclusory allegation of reckless driving. The caller alleged a specific and dangerous result of the driver’s conduct: running another car off the roadway, and the Court reasoned that bears too great a resemblance to behaviors related to drunk driving to be dismissed as an isolated example of recklessness. The experience of many officers suggests that a driver who almost strikes a vehicle or runs another vehicle off the roadway is likely intoxicated. As a result, the Court determined that the officer did not act unreasonably in stopping the driver whose alleged conduct was a significant indicator of drunk driving.

Curiously, the Court also noted that the absence of additional suspicious conduct, after the truck was first spotted by the CHP officer and after being followed for five minutes, did not dispel the reasonable suspicion of drunk driving. Justice Thomas opined that it was “hardly surprising that the appearance of a marked police car would inspire more careful driving and that, while extended observation of an allegedly drunk driver might eventually dispel a reasonable suspicion of intoxication…the five minute period in this case would hardly suffice in that regard. “An officer who already has such a reasonable suspicion need not [conduct surveillance on] a vehicle at length in order to personally observe suspicious driving.” Id at 18. The Court held that once reasonable suspicion of drunk driving arises, the reasonableness of the officer’s decision to stop a suspect does not turn on the availability of less intrusive investigatory techniques. Id at 18

It is interesting to note that Navarette probably could have been resolved under the rationale that the CHP officer was justified in stopping the truck for the crime of failing to remain at the scene of an accident. In Maryland at least, failing to remain at the scene of an accident does not require that the two vehicles actually make contact. It merely requires that one of the vehicles be involved in some sort of an accident (being run off the road should suffice) and that the vehicle causing the accident left the scene without checking for personal injury or property damage. It would seem that even had an anonymous third party called in the traffic incident, the police would have been justified in stopping the vehicle, to check for identity if nothing else.


While I certainly understand that many prosecutors are too busy to read anything other than the head notes of an opinion and rarely, if ever, read the dissent, it is strongly recommended that one take the time to read the dissent in Navarette. Not only is it extremely well thought out and reasoned, it is also quite entertaining. Justice Scalia makes some very valid points and one would be wise to know what they are when arguing a Fourth Amendment traffic stop based on an anonymous tip.


Navarette v. California should not be read so broadly as to authorize a traffic stop in every case involving an anonymous tip. Florida v. J.L. has not been overturned. Navarette merely expounds on Alabama v. White and Florida v. J.L. and holds that under certain circumstances, an anonymous tip can demonstrate sufficient indicia of reliability to provide the necessary reasonable suspicion to make an investigatory stop. Some of the factors to consider in order to determine “sufficient indicia of reliability” are:

  • Was the call made to a 911 Center; or
  • Were the police otherwise capable of ascertaining the identity of the caller;
  • Was the call made contemporaneously with the caller’s observations;
  • Did the caller have eyewitness knowledge of the incident;
  • Did the call appear to be reliable;
  • Did the call accurately predict “future behavior” that can be corroborated to assess the tipster’s credibility;
  • Was some of the caller’s information capable of being confirmed and was it, in fact, confirmed (time, place, tag number, vehicle description);
  • Did the call create a reasonable suspicion that “criminal activity was afoot”;
  • Does the content of the information possessed by the police and its degree of reliability give the officers reasonable suspicion that the subject was committing an ongoing crime;

While Navarette v. California certainly provides law enforcement with another useful tool to help determine reasonable suspicion that criminal activity is afoot, it does not stand for the proposition that police may always pull over a vehicle simply because of an anonymous tip.

*At the suppression hearing, Navarette’s attorney did not dispute that the caller identified herself by name. Because neither the caller nor the dispatcher who received the call were present at the hearing, the prosecutor did not introduce the recording into evidence. The prosecutor proceeded to treat the tip as anonymous and the lower courts followed suit.

As usual, please consult with your local State’s Attorneys’ Office when seeking guidance on this and other issues of law.

David Daggett is a Transportation Safety Resource Prosecutor with the Maryland State’s Attorney’s Association. The Maryland TSRP blogs are posted with the permission of the author.