(Slip Opinion) OCTOBER TERM, 2013 1 

Syllabus 

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader. 

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

SUPREME COURT OF THE UNITED STATES 

Syllabus 

PRADO NAVARETTE ET AL. v. CALIFORNIA 

CERTIORARI TO THE COURT OF APPEAL OF CALIFORNIA,
 

FIRST APPELLATE DISTRICT
 

No. 12–9490. Argued January 21, 2014—Decided April 22, 2014 

A California Highway Patrol officer stopped the pickup truck occupied

by petitioners because it matched the description of a vehicle that a 

911 caller had recently reported as having run her off the road. As he 

and a second officer approached the truck, they smelled marijuana.

They searched the truck’s bed, found 30 pounds of marijuana, and arrested petitioners. Petitioners moved to suppress the evidence, arguing that the traffic stop violated the Fourth Amendment. Their motion was denied, and they pleaded guilty to transporting marijuana. 

The California Court of Appeal affirmed, concluding that the officer

had reasonable suspicion to conduct an investigative stop. 

Held: The traffic stop complied with the Fourth Amendment because,

under the totality of the circumstances, the officer had reasonable

suspicion that the truck’s driver was intoxicated. Pp. 3–11.

(a) The Fourth Amendment permits brief investigative stops when

an officer has “a particularized and objective basis for suspecting the 

particular person stopped of . . . criminal activity.” United States v. 

Cortez, 449 U. S. 411, 417–418. Reasonable suspicion takes into account “the totality of the circumstances,” id., at 417, and depends

“upon both the content of information possessed by police and its degree of reliability,” Alabama v. White, 496 U. S. 325, 330. An anonymous tip alone seldom demonstrates sufficient reliability, White, 496 

U. S., at 329, but may do so under appropriate circumstances, id., at 

327. Pp. 3–5.

(b) The 911 call in this case bore adequate indicia of reliability for

the officer to credit the caller’s account. By reporting that she had 

been run off the road by a specific vehicle, the caller necessarily

claimed an eyewitness basis of knowledge. The apparently short 

time between the reported incident and the 911 call suggests that the 
 

2 PRADO NAVARETTE v. CALIFORNIA 

Syllabus 

caller had little time to fabricate the report. And a reasonable officer 

could conclude that a false tipster would think twice before using the

911 system, which has several technological and regulatory features 

that safeguard against making false reports with immunity. Pp. 5–8.

(c) Not only was the tip here reliable, but it also created reasonable

suspicion of drunk driving. Running another car off the road suggests the sort of impairment that characterizes drunk driving. While 

that conduct might be explained by another cause such as driver distraction, reasonable suspicion “need not rule out the possibility of innocent conduct.” United States v. Arvizu, 534 U. S. 266, 277. Finally,

the officer’s failure to observe additional suspicious conduct during 

the short period that he followed the truck did not dispel the reasonable suspicion of drunk driving, and the officer was not required to

surveil the truck for a longer period. Pp. 8–10. 

Affirmed. 

THOMAS, J., delivered the opinion of the Court, in which ROBERTS, 

C. J., and KENNEDY, BREYER, and ALITO, JJ., joined. SCALIA, J., filed a 

dissenting opinion, in which GINSBURG, SOTOMAYOR, and KAGAN, JJ., 

joined. 
 

 

_________________ 

_________________ 

 

Cite as: 572 U. S. ____ (2014) 1 

Opinion of the Court 

NOTICE: This opinion is subject to formal revision before publication in the

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press. 

SUPREME COURT OF THE UNITED STATES 

No. 12–9490 

LORENZO PRADO NAVARETTE AND JOSE PRADO 

NAVARETTE, PETITIONERS v. CALIFORNIA 

ON WRIT OF CERTIORARI TO THE COURT OF APPEAL OF 

CALIFORNIA, FIRST APPELLATE DISTRICT
 

[April 22, 2014] 

JUSTICE THOMAS delivered the opinion of the Court. 

After a 911 caller reported that a vehicle had run her off 

the road, a police officer located the vehicle she identified 

during the call and executed a traffic stop. We hold that 

the stop complied with the Fourth Amendment because, 

under the totality of the circumstances, the officer had

reasonable suspicion that the driver was intoxicated. 

I 

On August 23, 2008, a Mendocino County 911 dispatch

team for the California Highway Patrol (CHP) received a

call from another CHP dispatcher in neighboring Humboldt County. The Humboldt County dispatcher relayed a

tip from a 911 caller, which the Mendocino County team

recorded as follows: “‘Showing southbound Highway 1 at 

mile marker 88, Silver Ford 150 pickup. Plate of 8-David94925. Ran the reporting party off the roadway and was 

last seen approximately five [minutes] ago.’ ” App. 36a.

The Mendocino County team then broadcast that information to CHP officers at 3:47 p.m.

A CHP officer heading northbound toward the reported

vehicle responded to the broadcast. At 4:00 p.m., the 
 

 

 

 

 

2 PRADO NAVARETTE v. CALIFORNIA 

Opinion of the Court 

officer passed the truck near mile marker 69. At about 

4:05 p.m., after making a U-turn, he pulled the truck over.

A second officer, who had separately responded to the 

broadcast, also arrived on the scene. As the two officers 

approached the truck, they smelled marijuana. A search 

of the truck bed revealed 30 pounds of marijuana. The 

officers arrested the driver, petitioner Lorenzo Prado

Navarette, and the passenger, petitioner José Prado

Navarette. 

Petitioners moved to suppress the evidence, arguing

that the traffic stop violated the Fourth Amendment 

because the officer lacked reasonable suspicion of criminal

activity. Both the magistrate who presided over the suppression hearing and the Superior Court disagreed.1 

Petitioners pleaded guilty to transporting marijuana and 

were sentenced to 90 days in jail plus three years of 

probation.

The California Court of Appeal affirmed, concluding

that the officer had reasonable suspicion to conduct an

investigative stop. 2012 WL 4842651 (Oct. 12, 2012). The 

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 reliable 

enough to justify a traffic stop. Id., at *7. Finally, the

court 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. Id., at *9. The California Supreme Court 

—————— 

1At the suppression hearing, counsel for petitioners did not dispute

that the reporting party identified herself by name in the 911 call 

recording. Because neither the caller nor the Humboldt County dispatcher who received the call was present at the hearing, however, the 

prosecution did not introduce the recording into evidence. The prosecution proceeded to treat the tip as anonymous, and the lower courts

followed suit. See 2012 WL 4842651, *6 (Cal. Ct. App., Oct. 12, 2012). 
 

Cite as: 572 U. S. ____ (2014) 3 

Opinion of the Court 

denied review. We granted certiorari, 570 U. S. ___ 

(2013), and now affirm. 

II 

The Fourth Amendment permits brief investigative

stops—such as the traffic stop in this case—when a law 

enforcement officer has “a particularized and objective

basis for suspecting the particular person stopped of criminal activity.” United States v. Cortez, 449 U. S. 411, 417– 

418 (1981); see also Terry v. Ohio, 392 U. S. 1, 21–22 

(1968). The “reasonable suspicion” necessary to justify 

such a stop “is dependent upon both the content of information possessed by police and its degree of reliability.” 

Alabama v. White, 496 U. S. 325, 330 (1990). The standard takes into account “the totality of the circumstances—

the whole picture.” Cortez, supra, at 417. Although a 

mere “‘hunch’” does not create reasonable suspicion, 

Terry, supra, at 27, the level of suspicion the standard 

requires is “considerably less than proof of wrongdoing by 

a preponderance of the evidence,” and “obviously less” 

than is necessary for probable cause, United States v. 

Sokolow, 490 U. S. 1, 7 (1989). 

A 

These principles apply with full force to investigative

stops based on information from anonymous tips. We 

have firmly rejected the argument “that reasonable cause 

for a[n investigative stop] can only be based on the officer’s 

personal observation, rather than on information supplied 

by another person.” Adams v. Williams, 407 U. S. 143, 

147 (1972). Of course, “an anonymous tip alone seldom 

demonstrates the informant’s basis of knowledge or veracity.” White, 496 U. S., at 329 (emphasis added). That is 

because “ordinary citizens generally do not provide extensive recitations of the basis of their everyday observations,” and an anonymous tipster’s veracity is “‘by hypoth­
 

 

 

4 PRADO NAVARETTE v. CALIFORNIA 

Opinion of the Court 

esis largely unknown, and unknowable.’” Ibid. But under 

appropriate circumstances, an anonymous tip can demonstrate “sufficient indicia of reliability to provide reasonable suspicion to make [an] investigatory stop.” Id., at 327. 

Our decisions in Alabama v. White, 496 U. S. 325 (1990), 

and Florida v. J. L., 529 U. S. 266 (2000), are useful 

guides. In 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 with a broken right tail light. The tipster further

asserted that the woman would be transporting cocaine.

496 U. S., at 327. After confirming the innocent details,

officers stopped the station wagon as it neared the motel

and found cocaine in the vehicle. Id., at 331. We held that 

the officers’ corroboration of certain details made the 

anonymous tip sufficiently reliable to create reasonable 

suspicion of criminal activity. By accurately predicting

future behavior, the tipster demonstrated “a special familiarity with respondent’s affairs,” which in turn implied

that the tipster had “access to reliable information about

that individual’s illegal activities.” Id., at 332. We also 

recognized that an informant who is proved to tell the 

truth about some things is more likely to tell the truth

about other things, “including the claim that the object of

the tip is engaged in criminal activity.” Id., at 331 (citing 

Illinois v. Gates, 462 U. S. 213, 244 (1983)). 

In J. L., by contrast, we determined that no reasonable 

suspicion arose from a bare-bones tip that a young black 

male in a plaid shirt standing at a bus stop was carrying a 

gun. 529 U. S., at 268. 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’s affairs. Id., at 

271. As a result, police had no basis for believing “that the 

tipster ha[d] knowledge of concealed criminal activity.” 

Id., at 272. Furthermore, the tip included no predictions

of future behavior that could be corroborated to assess the 
 

 

Cite as: 572 U. S. ____ (2014) 5 

Opinion of the Court 

tipster’s credibility. Id., at 271. We accordingly concluded 

that the tip was insufficiently reliable to justify a stop and 

frisk. 

B 

The initial question in this case is whether the 911 call

was sufficiently reliable to credit the allegation that petitioners’ truck “ran the [caller] off the roadway.” Even 

assuming for present purposes that the 911 call was anonymous, see n. 1, supra, we conclude that the call bore 

adequate indicia of reliability for the officer to credit the

caller’s account. The officer was therefore justified in 

proceeding from the premise that the truck had, in fact, 

caused the caller’s car to be dangerously diverted from the 

highway.

By reporting that she had been run off the road by a

specific vehicle—a silver Ford F-150 pickup, license plate 

8D94925—the caller necessarily claimed eyewitness 

knowledge of the alleged dangerous driving. That basis of 

knowledge lends significant support to the tip’s reliability.

See Gates, supra, at 234 (“[An informant’s] explicit and 

detailed description of alleged wrongdoing, along with a

statement that the event was observed firsthand, entitles 

his tip to greater weight than might otherwise be the

case”); Spinelli v. United States, 393 U. S. 410, 416 (1969) 

(a tip of illegal gambling is less reliable when “it is not 

alleged that the informant personally observed [the defendant] at work or that he had ever placed a bet with 

him”). This is in contrast to J. L., where the tip provided

no basis for concluding that the tipster had actually seen

the gun. 529 U. S., at 271. Even in White, where we 

upheld the stop, there was scant evidence that the tipster

had actually observed cocaine in the station wagon. We 

called White a “‘close case’” because “[k]nowledge about a

person’s future movements indicates some familiarity with 

that person’s affairs, but having such knowledge does not 
 

 

6 PRADO NAVARETTE v. CALIFORNIA 

Opinion of the Court 

necessarily imply that the informant knows, in particular,

whether that person is carrying hidden contraband.” 529 

U. S., at 271. A driver’s claim that another vehicle ran her 

off the road, however, necessarily implies that the informant knows the other car was driven dangerously. 

There is also reason to think that the 911 caller in this 

case was telling the truth. Police confirmed the truck’s 

location near mile marker 69 (roughly 19 highway miles 

south of the location reported in the 911 call) at 4:00 p.m.

(roughly 18 minutes after the 911 call). That timeline of 

events suggests that the caller reported the incident soon 

after she was run off the road. That sort of contemporaneous report has long been treated as especially reliable. In

evidence law, we generally credit the proposition that

statements about an event and made soon after perceiving

that event are especially trustworthy because “substantial 

contemporaneity of event and statement negate the likelihood of deliberate or conscious misrepresentation.” Advisory Committee’s Notes on Fed. Rule Evid. 803(1), 28

U. S. C. App., p. 371 (describing the rationale for the

hearsay exception for “present sense impression[s]”). A 

similar rationale applies to a “statement relating to a 

startling event”—such as getting run off the road—“made

while the declarant was under the stress of excitement 

that it caused.” Fed. Rule Evid. 803(2) (hearsay exception 

for “excited utterances”). Unsurprisingly, 911 calls that

would otherwise be inadmissible hearsay have often been

admitted on those grounds. See D. Binder, Hearsay 

Handbook §8.1, pp. 257–259 (4th ed. 2013–2014) (citing 

cases admitting 911 calls as present sense impressions); 

id., §9.1, at 274–275 (911 calls admitted as excited utterances). There was no indication that the tip in J. L. (or

even in White) was contemporaneous with the observation 

of criminal activity or made under the stress of excitement

caused by a startling event, but those considerations

weigh in favor of the caller’s veracity here. 
 

Cite as: 572 U. S. ____ (2014) 7 

Opinion of the Court 

Another indicator of veracity is the caller’s use of the 

911 emergency system. See Brief for Respondent 40–41,

44; Brief for United States as Amicus Curiae 16–18. A 911 

call has some features that allow for identifying and tracing callers, and thus provide some safeguards against 

making false reports with immunity. See J. L., supra, at 

276 (KENNEDY, J., concurring). As this case illustrates, 

see n. 1, supra, 911 calls can be recorded, which provides 

victims with an opportunity to identify the false tipster’s 

voice and subject him to prosecution, see, e.g., Cal. Penal 

Code Ann. §653x (West 2010) (makes “telephon[ing] the 

911 emergency line with the intent to annoy or harass”

punishable by imprisonment and fine); see also §148.3

(2014 West Cum. Supp.) (prohibits falsely reporting “that 

an ‘emergency’ exists”); §148.5 (prohibits falsely reporting 

“that a felony or misdemeanor has been committed”). The 

911 system also permits law enforcement to verify important information about the caller. In 1998, the Federal 

Communications Commission (FCC) began to require 

cellular carriers to relay the caller’s phone number to 911 

dispatchers. 47 CFR §20.18(d)(1) (2013) (FCC’s “Phase I

enhanced 911 services” requirements). Beginning in 2001, 

carriers have been required to identify the caller’s geographic location with increasing specificity. §§20.18(e)–(h) 

(“Phase II enhanced 911 service” requirements). And 

although callers may ordinarily block call recipients from

obtaining their identifying information, FCC regulations

exempt 911 calls from that privilege. §§64.1601(b),

(d)(4)(ii) (“911 emergency services” exemption from rule

that, when a caller so requests, “a carrier may not reveal

that caller’s number or name”). None of this is to suggest 

that tips in 911 calls are per se reliable. Given the foregoing technological and regulatory developments, however, a 

reasonable officer could conclude that a false tipster would 

think twice before using such a system. The caller’s use of 

the 911 system is therefore one of the relevant circum­
 

 

 

 

 

8 PRADO NAVARETTE v. CALIFORNIA 

Opinion of the Court 

stances that, taken together, justified the officer’s reliance 

on the information reported in the 911 call. 

C 

Even a reliable tip will justify an investigative stop only 

if it creates reasonable suspicion that “criminal activity 

may be afoot.” Terry, 392 U. S., at 30. We must therefore 

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. See Cortez, 449 U. S., at 417 

(“An investigatory stop must be justified by some objective 

manifestation that the person stopped is, or is about to be, 

engaged in criminal activity”). We conclude that the 

behavior alleged by the 911 caller, “viewed from the

standpoint of an objectively reasonable police officer,

amount[s] to reasonable suspicion” of drunk driving. 

Ornelas v. United States, 517 U. S. 690, 696 (1996). The 

stop was therefore proper.2 

Reasonable suspicion depends on “‘“the factual and 

practical considerations of everyday life on which reasonable and prudent men, not legal technicians, act.”’” Id., at 

695. Under that commonsense approach, we can appropriately recognize certain driving behaviors as sound 

indicia of drunk driving. See, e.g., People v. Wells, 

38 Cal. 4th 1078, 1081, 136 P. 3d 810, 811 (2006) (“‘weaving all over the roadway’”); State v. Prendergast, 103 Haw. 

451, 452–453, 83 P. 3d 714, 715–716 (2004) (“cross[ing]

over the center line” on a highway and “almost caus[ing]

several head-on collisions”); State v. Golotta, 178 N. J. 

205, 209, 837 A. 2d 359, 361 (2003) (driving “‘all over 

the road’” and “‘weaving back and forth’”); State v. 

—————— 

2Because we conclude that the 911 call created reasonable suspicion 

of an ongoing crime, we need not address under what circumstances a 

stop is justified by the need to investigate completed criminal activity. 

Cf. United States v. Hensley, 469 U. S. 221, 229 (1985). 
 

 

 

 

 

Cite as: 572 U. S. ____ (2014) 9 

Opinion of the Court 

Walshire, 634 N. W. 2d 625, 626 (Iowa 2001) (“driving in

the median”). Indeed, the accumulated experience of 

thousands of officers suggests that these sorts of erratic

behaviors are strongly correlated with drunk driving.

See Nat. Highway Traffic Safety Admin., The Visual 

Detection of DWI Motorists 4–5 (Mar. 2010), online at

http://nhtsa.gov/staticfiles/nti/pdf/808677.pdf (as visited 

Apr. 18, 2014, and available in Clerk of Court’s case file).

Of course, not all traffic infractions imply intoxication.

Unconfirmed reports of driving without a seatbelt or

slightly over the speed limit, for example, are so tenuously 

connected to drunk driving that a stop on those grounds 

alone would be constitutionally suspect. But a reliable tip

alleging the dangerous behaviors discussed above generally would justify a traffic stop on suspicion of drunk 

driving.

The 911 caller in this case reported more than a minor 

traffic infraction and more than a conclusory allegation of 

drunk or reckless driving. Instead, she alleged a specific

and dangerous result of the driver’s conduct: running

another car off the highway. That conduct bears too great

a resemblance to paradigmatic manifestations of drunk 

driving to be dismissed as an isolated example of recklessness. Running another vehicle off the road suggests lanepositioning problems, decreased vigilance, impaired judgment, or some combination of those recognized drunk 

driving cues. See Visual Detection of DWI Motorists 4–5. 

And the experience of many officers suggests that a driver

who almost strikes a vehicle or another object—the exact 

scenario that ordinarily causes “running [another vehicle] 

off the roadway”—is likely intoxicated. See id., at 5, 8. 

As a result, we cannot say that the officer acted unreasonably under these circumstances in stopping a driver

whose alleged conduct was a significant indicator of drunk 

driving.

Petitioners’ attempts to second-guess the officer’s rea­
 

10 PRADO NAVARETTE v. CALIFORNIA 

Opinion of the Court 

sonable suspicion of drunk driving are unavailing. It is 

true that the reported behavior might also be explained 

by, for example, a driver responding to “an unruly child or

other distraction.” Brief for Petitioners 21. But we have 

consistently recognized that reasonable suspicion “need 

not rule out the possibility of innocent conduct.” United 

States v. Arvizu, 534 U. S. 266, 277 (2002).

Nor did the absence of additional suspicious conduct,

after the vehicle was first spotted by an officer, dispel the 

reasonable suspicion of drunk driving. Brief for Petitioners 23–24. It is hardly surprising that the appearance of a 

marked police car would inspire more careful driving for a

time. Cf. Arvizu, supra, at 275 (“‘[s]lowing down after

spotting a law enforcement vehicle’” does not dispel reasonable suspicion of criminal activity). Extended observation of an allegedly drunk driver might eventually dispel a 

reasonable suspicion of intoxication, but the 5-minute

period in this case hardly sufficed in that regard. Of 

course, an officer who already has such a reasonable suspicion need not surveil a vehicle at length in order to

personally observe suspicious driving. See Adams v. 

Williams, 407 U. S., at 147 (repudiating the argument 

that “reasonable cause for a[n investigative stop] can only 

be based on the officer’s personal observation”). Once 

reasonable suspicion of drunk driving arises, “[t]he reasonableness of the officer’s decision to stop a suspect does 

not turn on the availability of less intrusive investigatory 

techniques.” Sokolow, 490 U. S., at 11. This would be a 

particularly inappropriate context to depart from that

settled rule, because allowing a drunk driver a second 

chance for dangerous conduct could have disastrous 

consequences. 

III

 Like White, this is a “close case.” 496 U. S., at 332. As 

in that case, the indicia of the 911 caller’s reliability here 
Cite as: 572 U. S. ____ (2014) 11 

Opinion of the Court 

are stronger than those in J. L., where we held that a 

bare-bones tip was unreliable. 529 U. S., at 271. Although the indicia present here are different from those we

found sufficient in White, there is more than one way to

demonstrate “a particularized and objective basis for 

suspecting the particular person stopped of criminal activity.” Cortez, 449 U. S., at 417–418. Under 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. We 

accordingly affirm. 

It is so ordered. 
_________________ 

_________________ 

 

Cite as: 572 U. S. ____ (2014) 1 

SCALIA, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 12–9490 

LORENZO PRADO NAVARETTE AND JOSE PRADO 

NAVARETTE, PETITIONERS v. CALIFORNIA 

ON WRIT OF CERTIORARI TO THE COURT OF APPEAL OF 

CALIFORNIA, FIRST APPELLATE DISTRICT
 

[April 22, 2014] 

JUSTICE SCALIA, with whom JUSTICE GINSBURG, 

JUSTICE SOTOMAYOR, and JUSTICE KAGAN join, dissenting. 

The California Court of Appeal in this case relied on

jurisprudence from the California Supreme Court (adopted

as well by other courts) to the effect that “an anonymous

and uncorroborated tip regarding a possibly intoxicated

highway driver” provides without more the reasonable 

suspicion necessary to justify a stop. People v. Wells, 38 

Cal. 4th l078, 1082, 136 P. 3d 810, 812, (2006). See also, 

e.g., United States v. Wheat, 278 F. 3d 722, 729–730 (CA8 

2001); State v. Walshire, 634 N. W. 2d 625, 626–627, 630 

(Iowa 2001). Today’s opinion does not explicitly adopt 

such a departure from our normal Fourth Amendment

requirement that anonymous tips must be corroborated; it 

purports to adhere to our prior cases, such as Florida v. 

J. L., 529 U. S. 266 (2000), and Alabama v. White, 496 

U. S. 325 (1990). Be not deceived. 

Law enforcement agencies follow closely our judgments 

on matters such as this, and they will identify at once our 

new rule: So long as the caller identifies where the car is, 

anonymous claims of a single instance of possibly careless

or reckless driving, called in to 911, will support a traffic 

stop. This is not my concept, and I am sure would not be

the Framers’, of a people secure from unreasonable

searches and seizures. I would reverse the judgment of 
 

 

2 PRADO NAVARETTE v. CALIFORNIA 

SCALIA, J., dissenting 

the Court of Appeal of California. 

I 

The California Highway Patrol in this case knew nothing about the tipster on whose word—and that alone—

they seized Lorenzo and José Prado Navarette. They did 

not know her name.1 They did not know her phone number or address. They did not even know where she called

from (she may have dialed in from a neighboring county,

App. 33a–34a). 

The tipster said the truck had “[run her] off the roadway,” id., at 36a, but the police had no reason to credit 

that charge and many reasons to doubt it, beginning with

the peculiar fact that the accusation was anonymous. 

“[E]liminating accountability . . . is ordinarily the very 

purpose of anonymity.” McIntyre v. Ohio Elections 

Comm’n, 514 U. S. 334, 385 (1995) (SCALIA, J., dissenting).

The unnamed tipster “can lie with impunity,” J. L., supra, 

at 275 (KENNEDY, J., concurring). Anonymity is especially

suspicious with respect to the call that is the subject of the 

present case. When does a victim complain to the police

about an arguably criminal act (running the victim off the 

road) without giving his identity, so that he can accuse 

and testify when the culprit is caught?

The question before us, the Court agrees, ante, at 8, is 

whether the “content of information possessed by police 

and its degree of reliability,” White, 496 U. S., at 330, gave 

the officers reasonable suspicion that the driver of the

truck (Lorenzo) was committing an ongoing crime. When 

the only source of the government’s information is an 

informant’s tip, we ask whether the tip bears sufficient 

“‘indicia of reliability,’” id., at 328, to establish “a particularized and objective basis for suspecting the particular 

—————— 

1There was some indication below that the tipster was a woman. See 

App. 18a. Beyond that detail, we must, as the Court notes, ante, at 2, 

n. 1, assume that the identity of the tipster was unknown. 
Cite as: 572 U. S. ____ (2014) 3 

SCALIA, J., dissenting 

person stopped of criminal activity,” United States v. 

Cortez, 449 U. S. 411, 417–418 (1981). 

The most extreme case, before this one, in which an 

anonymous tip was found to meet this standard was 

White, supra. There the reliability of the tip was established by the fact that it predicted the target’s behavior in

the finest detail—a detail that could be known only by

someone familiar with the target’s business: She would, 

the tipster said, leave a particular apartment building, get

into a brown Plymouth station wagon with a broken right 

tail light, and drive immediately to a particular motel. 

Id., at 327. Very few persons would have such intimate 

knowledge, and hence knowledge of the unobservable fact 

that the woman was carrying unlawful drugs was plausible. Id., at 332. Here the Court makes a big deal of the

fact that the tipster was dead right about the fact that a 

silver Ford F-150 truck (license plate 8D94925) was traveling south on Highway 1 somewhere near mile marker

88. But everyone in the world who saw the car would have

that knowledge, and anyone who wanted the car stopped 

would have to provide that information. Unlike the situation in White, that generally available knowledge in no 

way makes it plausible that the tipster saw the car run 

someone off the road. 

The Court says, ante, at 5, that “[b]y reporting that she

had been run off the road by a specific vehicle . . . the 

caller necessarily claimed eyewitness knowledge.” So 

what? The issue is not how she claimed to know, but 

whether what she claimed to know was true. The claim to 

“eyewitness knowledge” of being run off the road supports 

not at all its veracity; nor does the amazing, mystifying

prediction (so far short of what existed in White) that the 

petitioners’ truck would be heading south on Highway 1. 

The Court finds “reason to think” that the informant 

“was telling the truth” in the fact that police observation 

confirmed that the truck had been driving near the spot at 
 

 

4 PRADO NAVARETTE v. CALIFORNIA 

SCALIA, J., dissenting 

which, and at the approximate time at which, the tipster

alleged she had been run off the road. Ante, at 6. According to the Court, the statement therefore qualifies as a 

“‘present sense impression’” or “‘excited utterance,’” kinds

of hearsay that the law deems categorically admissible

given their low likelihood of reflecting “‘deliberate or

conscious misrepresentation.’” Ibid. (quoting Advisory 

Committee’s Notes on Fed. Rule Evid. 803(1), 28 U. S. C.

App., p. 371). So, the Court says, we can fairly suppose

that the accusation was true. 

No, we cannot. To begin with, it is questionable whether

either the “present sense impression” or the “excited utterance” exception to the hearsay rule applies here. The 

classic “present sense impression” is the recounting of an

event that is occurring before the declarant’s eyes, as the 

declarant is speaking (“I am watching the Hindenburg 

explode!”). See 2 K. Broun, McCormick on Evidence 362 

(7th ed. 2013) (hereinafter McCormick). And the classic 

“excited utterance” is a statement elicited, almost involuntarily, by the shock of what the declarant is immediately

witnessing (“My God, those people will be killed!”). See 

id., at 368–369. It is the immediacy that gives the statement some credibility; the declarant has not had time to 

dissemble or embellish. There is no such immediacy here. 

The declarant had time to observe the license number of 

the offending vehicle, 8D94925 (a difficult task if she was 

forced off the road and the vehicle was speeding away), to

bring her car to a halt, to copy down the observed license 

number (presumably), and (if she was using her own cell 

phone) to dial a call to the police from the stopped car.

Plenty of time to dissemble or embellish.

Moreover, even assuming that less than true immediacy 

will suffice for these hearsay exceptions to apply, the 

tipster’s statement would run into additional barriers to 

admissibility and acceptance. According to the very Advisory Committee’s Notes from which the Court quotes, 
 

Cite as: 572 U. S. ____ (2014) 5 

SCALIA, J., dissenting 

cases addressing an unidentified declarant’s present sense 

impression “indicate hesitancy in upholding the statement 

alone as sufficient” proof of the reported event. 28 U. S. C. 

App., at 371; see also 7 M. Graham, Handbook of Federal 

Evidence 19–20 (7th ed. 2012). For excited utterances as 

well, the “knotty theoretical” question of statement-alone 

admissibility persists—seemingly even when the declarant 

is known. 2 McCormick 368. “Some courts . . . have taken 

the position that an excited utterance is admissible only if 

other proof is presented which supports a finding of fact 

that the exciting event did occur. The issue has not yet

been resolved under the Federal Rules.” Id., at 367–368 

(footnote omitted). It is even unsettled whether excited 

utterances of an unknown declarant are ever admissible. 

A leading treatise reports that “the courts have been 

reluctant to admit such statements, principally because of

uncertainty that foundational requirements, including the

impact of the event on the declarant, have been satisfied.” 

Id., at 372. In sum, it is unlikely that the law of evidence

would deem the mystery caller in this case “especially 

trustworthy,” ante, at 6. 

Finally, and least tenably, the Court says that another

“indicator of veracity” is the anonymous tipster’s mere

“use of the 911 emergency system,” ante, at 7. Because, 

you see, recent “technological and regulatory developments” suggest that the identities of unnamed 911 callers 

are increasingly less likely to remain unknown. Ibid. 

Indeed, the systems are able to identify “the caller’s geographic location with increasing specificity.” Ibid. Amici 

disagree with this, see Brief for National Association of 

Criminal Defense Lawyers et al. 8–12, and the present 

case surely suggests that amici are right—since we know 

neither the identity of the tipster nor even the county from

which the call was made. But assuming the Court is right

about the ease of identifying 911 callers, it proves absolutely nothing in the present case unless the anonymous 
 

6 PRADO NAVARETTE v. CALIFORNIA 

SCALIA, J., dissenting 

caller was aware of that fact. “It is the tipster’s belief in 

anonymity, not its reality, that will control his behavior.” 

Id., at 10 (emphasis added). There is no reason to believe 

that your average anonymous 911 tipster is aware that 

911 callers are readily identifiable.2 

II 

All that has been said up to now assumes that the anonymous caller made, at least in effect, an accusation of 

drunken driving. But in fact she did not. She said that 

the petitioners’ truck “‘[r]an [me] off the roadway.’” App. 

36a. That neither asserts that the driver was drunk nor 

even raises the likelihood that the driver was drunk. The 

most it conveys is that the truck did some apparently

nontypical thing that forced the tipster off the roadway,

whether partly or fully, temporarily or permanently. Who 

really knows what (if anything) happened? The truck 

might have swerved to avoid an animal, a pothole, or a 

jaywalking pedestrian. 

But let us assume the worst of the many possibilities: 

that it was a careless, reckless, or even intentional maneuver that forced the tipster off the road. Lorenzo might

have been distracted by his use of a hands-free cell phone, 

see Strayer, Drews, & Crouch, A Comparison of the Cell 

Phone Driver and the Drunk Driver, 48 Human Factors 381, 

388 (2006), or distracted by an intense sports argument with

José, see D. Strayer et al., AAA Foundation for Traffic 

Safety, Measuring Cognitive Distraction in the Automobile 

28 (June 2013), online at https://www.aaafoundation.org/

sites/default/files/MeasuringCognitiveDistractions.pdf as visited

Apr. 17, 2014, and available in Clerk of Court’s case file). 

—————— 

2The Court’s discussion of reliable 911 traceability has so little relevance to the present case that one must surmise it has been included

merely to assure officers in the future that anonymous 911 accusations—even untraced ones—are not as suspect (and hence as unreliable) as other anonymous accusations. That is unfortunate. 
 

Cite as: 572 U. S. ____ (2014) 7 

SCALIA, J., dissenting 

Or, indeed, he might have intentionally forced the tipster

off the road because of some personal animus, or hostility

to her “Make Love, Not War” bumper sticker. I fail to see 

how reasonable suspicion of a discrete instance of irregular

or hazardous driving generates a reasonable suspicion of 

ongoing intoxicated driving. What proportion of the hundreds of thousands—perhaps millions—of careless, reckless, or intentional traffic violations committed each day is

attributable to drunken drivers? I say 0.1 percent. I have 

no basis for that except my own guesswork. But unless 

the Court has some basis in reality to believe that the

proportion is many orders of magnitude above that—say 1

in 10 or at least 1 in 20—it has no grounds for its unsupported assertion that the tipster’s report in this case gave 

rise to a reasonable suspicion of drunken driving. 

Bear in mind that that is the only basis for the stop that

has been asserted in this litigation.3 The stop required 

suspicion of an ongoing crime, not merely suspicion of 

having run someone off the road earlier. And driving

while being a careless or reckless person, unlike driving

while being a drunk person, is not an ongoing crime. In 

other words, in order to stop the petitioners the officers

here not only had to assume without basis the accuracy of

the anonymous accusation but also had to posit an unlikely 

reason (drunkenness) for the accused behavior.

In sum, at the moment the police spotted the truck, it

was more than merely “possib[le]” that the petitioners

were not committing an ongoing traffic crime. United 

States v. Arvizu, 534 U. S. 266, 277 (2002) (emphasis 

—————— 

3The circumstances that may justify a stop under Terry v. Ohio, 392 

U. S. 1 (1968), to investigate past criminal activity are far from clear, 

see United States v. Hensley, 469 U. S. 221, 229 (1985), and have not

been discussed in this litigation. Hence, the Court says it “need not

address” that question. Ante, at 8, n. 2. I need not either. This case 

has been litigated on the assumption that only suspicion of ongoing 

intoxicated or reckless driving could have supported this stop. 
 

 

8 PRADO NAVARETTE v. CALIFORNIA 

SCALIA, J., dissenting 

added). It was overwhelmingly likely that they were not. 

III 

It gets worse. Not only, it turns out, did the police have 

no good reason at first to believe that Lorenzo was driving 

drunk, they had very good reason at last to know that he 

was not. The Court concludes that the tip, plus confirmation of the truck’s location, produced reasonable suspicion

that the truck not only had been but still was barreling

dangerously and drunkenly down Highway 1. Ante, at 8– 

10. In fact, alas, it was not, and the officers knew it. They

followed the truck for five minutes, presumably to see if it

was being operated recklessly. And that was good police 

work. While the anonymous tip was not enough to support a stop for drunken driving under Terry v. Ohio, 392 

U. S. 1 (1968), it was surely enough to counsel observation 

of the truck to see if it was driven by a drunken driver. 

But the pesky little detail left out of the Court’s reasonable-suspicion equation is that, for the five minutes that the 

truck was being followed (five minutes is a long time),

Lorenzo’s driving was irreproachable. Had the officers 

witnessed the petitioners violate a single traffic law, they 

would have had cause to stop the truck, Whren v. United 

States, 517 U. S. 806, 810 (1996), and this case would not

be before us. And not only was the driving irreproachable, 

but the State offers no evidence to suggest that the petitioners even did anything suspicious, such as suddenly 

slowing down, pulling off to the side of the road, or turning 

somewhere to see whether they were being followed. Cf. 

Arvizu, supra, at 270–271, 277 (concluding that an officer’s

suspicion of criminality was enhanced when the driver, 

upon seeing that he was being followed, “slowed dramatically,” “appeared stiff,” and “seemed to be trying to pretend” that the patrol car was not there). Consequently,

the tip’s suggestion of ongoing drunken driving (if it could 

be deemed to suggest that) not only went uncorroborated; 
 

Cite as: 572 U. S. ____ (2014) 9 

SCALIA, J., dissenting 

it was affirmatively undermined.

A hypothetical variation on the facts of this case illustrates the point. Suppose an anonymous tipster reports

that, while following near mile marker 88 a silver Ford 

F-150, license plate 8D949925, traveling southbound on 

Highway 1, she saw in the truck’s open cab several fivefoot-tall stacks of what was unmistakably baled cannabis. 

Two minutes later, a highway patrolman spots the truck

exactly where the tip suggested it would be, begins following it, but sees nothing in the truck’s cab. It is not enough

to say that the officer’s observation merely failed to corroborate the tipster’s accusation. It is more precise to say

that the officer’s observation discredited the informant’s 

accusation: The crime was supposedly occurring (and

would continue to occur) in plain view, but the police saw 

nothing. Similarly, here, the crime supposedly suggested

by the tip was ongoing intoxicated driving, the hallmarks

of which are many, readily identifiable, and difficult to

conceal. That the officers witnessed nary a minor traffic 

violation nor any other “sound indici[um] of drunk driving,” ante, at 8, strongly suggests that the suspected crime 

was not occurring after all. The tip’s implication of continuing criminality, already weak, grew even weaker.

Resisting this line of reasoning, the Court curiously

asserts that, since drunk drivers who see marked squad 

cars in their rearview mirrors may evade detection simply 

by driving “more careful[ly],” the “absence of additional 

suspicious conduct” is “hardly surprising” and thus largely

irrelevant. Ante, at 10. Whether a drunk driver drives 

drunkenly, the Court seems to think, is up to him. That is 

not how I understand the influence of alcohol. I subscribe 

to the more traditional view that the dangers of intoxicated driving are the intoxicant’s impairing effects on the

body—effects that no mere act of the will can resist. See, 

e.g., A. Dasgupta, The Science of Drinking: How Alcohol 

Affects Your Body and Mind 39 (explaining that the physi­
 

 

10 PRADO NAVARETTE v. CALIFORNIA 

SCALIA, J., dissenting 

ological effect of a blood alcohol content between 0.08 and 

0.109, for example, is “sever[e] impair[ment]” of “[b]alance,

speech, hearing, and reaction time,” as well as one’s general “ability to drive a motor vehicle”). Consistent with 

this view, I take it as a fundamental premise of our intoxicated-driving laws that a driver soused enough to swerve

once can be expected to swerve again—and soon. If he 

does not, and if the only evidence of his first episode of 

irregular driving is a mere inference from an uncorroborated, vague, and nameless tip, then the Fourth Amendment requires that he be left alone. 

* * * 

The Court’s opinion serves up a freedom-destroying 

cocktail consisting of two parts patent falsity: (1) that

anonymous 911 reports of traffic violations are reliable so 

long as they correctly identify a car and its location, and 

(2) that a single instance of careless or reckless driving

necessarily supports a reasonable suspicion of drunkenness. 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, he never alleged drunkenness, but 

merely called in a traffic violation—and on that point his

word is as good as his victim’s. 

Drunken driving is a serious matter, but so is the loss of

our freedom to come and go as we please without police 

interference. To prevent and detect murder we do not

allow searches without probable cause or targeted Terry 

stops without reasonable suspicion. We should not do so 

for drunken driving either. After today’s opinion all of us 

on the road, and not just drug dealers, are at risk of having our freedom of movement curtailed on suspicion of 

drunkenness, based upon a phone tip, true or false, of a 
Cite as: 572 U. S. ____ (2014) 11 

SCALIA, J., dissenting 

single instance of careless driving. I respectfully dissent.