(Slip Opinion) OCTOBER TERM, 2014 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 

RODRIGUEZ v. UNITED STATES 

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR 

THE EIGHTH CIRCUIT 

No. 13–9972. Argued January 21, 2015—Decided April 21, 2015 

Officer Struble, a K–9 officer, stopped petitioner Rodriguez for driving 

on a highway shoulder, a violation of Nebraska law. After Struble attended to everything relating to the stop, including, inter alia, checking the driver’s licenses of Rodriguez and his passenger and issuing a 

warning for the traffic offense, he asked Rodriguez for permission to

walk his dog around the vehicle. When Rodriguez refused, Struble 

detained him until a second officer arrived. Struble then retrieved 

his dog, who alerted to the presence of drugs in the vehicle. The ensuing search revealed methamphetamine. Seven or eight minutes 

elapsed from the time Struble issued the written warning until the 

dog alerted.

Rodriguez was indicted on federal drug charges. He moved to suppress the evidence seized from the vehicle on the ground, among others, that Struble had prolonged the traffic stop without reasonable

suspicion in order to conduct the dog sniff. The Magistrate Judge 

recommended denial of the motion. He found no reasonable suspicion

supporting detention once Struble issued the written warning. Under Eighth Circuit precedent, however, he concluded that prolonging 

the stop by “seven to eight minutes” for the dog sniff was only a de 

minimis intrusion on Rodriguez’s Fourth Amendment rights and was

for that reason permissible. The District Court then denied the motion to suppress. Rodriguez entered a conditional guilty plea and was

sentenced to five years in prison. The Eighth Circuit affirmed. Noting that the seven or eight minute delay was an acceptable “de minimis intrusion on Rodriguez’s personal liberty,” the court declined to 

reach the question whether Struble had reasonable suspicion to continue Rodriguez’s detention after issuing the written warning. 

Held: 
 

 

 

 

2 RODRIGUEZ v. UNITED STATES 

Syllabus 

1. Absent reasonable suspicion, police extension of a traffic stop

in order to conduct a dog sniff violates the Constitution’s shield

against unreasonable seizures. 

A routine traffic stop is more like a brief stop under Terry v. Ohio, 

392 U. S. 1, than an arrest, see, e.g., Arizona v. Johnson, 555 U. S. 

323, 330. Its tolerable duration is determined by the seizure’s “mission,” which is to address the traffic violation that warranted the 

stop, Illinois v. Caballes, 543 U. S. 405, 407 and attend to related 

safety concerns. Authority for the seizure ends when tasks tied to 

the traffic infraction are—or reasonably should have been— 

completed. The Fourth Amendment may tolerate certain unrelated

investigations that do not lengthen the roadside detention, Johnson, 

555 U. S., at 327–328 (questioning); Caballes, 543 U. S., at 406, 408 

(dog sniff), but a traffic stop “become[s] unlawful if it is prolonged beyond the time reasonably required to complete th[e] mission” of issuing a warning ticket, id., at 407. 

Beyond determining whether to issue a traffic ticket, an officer’s

mission during a traffic stop typically includes checking the driver’s

license, determining whether there are outstanding warrants against

the driver, and inspecting the automobile’s registration and proof of

insurance. These checks serve the same objective as enforcement of

the traffic code: ensuring that vehicles on the road are operated safely and responsibly. See Delaware v. Prouse, 440 U. S. 648, 658–659. 

Lacking the same close connection to roadway safety as the ordinary 

inquiries, a dog sniff is not fairly characterized as part of the officer’s

traffic mission. 

In concluding that the de minimis intrusion here could be offset by

the Government’s interest in stopping the flow of illegal drugs, the 

Eighth Circuit relied on Pennsylvania v. Mimms, 434 U. S. 106. The 

Court reasoned in Mimms that the government’s “legitimate and

weighty” interest in officer safety outweighed the “de minimis” additional intrusion of requiring a driver, lawfully stopped, to exit a vehicle, id., at 110–111. The officer-safety interest recognized in Mimms, 

however, stemmed from the danger to the officer associated with the 

traffic stop itself. On-scene investigation into other crimes, in contrast, detours from the officer’s traffic-control mission and therefore 

gains no support from Mimms. 

The Government’s argument that an officer who completes all traffic-related tasks expeditiously should earn extra time to pursue an 

unrelated criminal investigation is unpersuasive, for a traffic stop

“prolonged beyond” the time in fact needed for the officer to complete

his traffic-based inquiries is “unlawful,” Caballes, 543 U. S., at 407. 

The critical question is not whether the dog sniff occurs before or after the officer issues a ticket, but whether conducting the sniff adds 
 

Cite as: 575 U. S. ____ (2015) 3 

Syllabus 

time to the stop. Pp. 5–8.

2. The determination adopted by the District Court that detention for the dog sniff was not independently supported by individualized suspicion was not reviewed by the Eighth Circuit. That question 

therefore remains open for consideration on remand. P. 9. 

741 F. 3d 905, vacated and remanded. 

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

C. J., and SCALIA, BREYER, SOTOMAYOR, and KAGAN, JJ., joined. KENNEDY, J., filed a dissenting opinion. THOMAS, J., filed a dissenting opinion, in which ALITO, J., joined, and in which KENNEDY, J., joined as to 

all but Part III. ALITO, J., filed a dissenting opinion. 
 

 

_________________ 

_________________ 

Cite as: 575 U. S. ____ (2015) 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. 13–9972 

DENNYS RODRIGUEZ, PETITIONER v.

 UNITED STATES
 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE EIGHTH CIRCUIT
 

[April 21, 2015] 

JUSTICE GINSBURG delivered the opinion of the Court. 

In Illinois v. Caballes, 543 U. S. 405 (2005), this Court 

held that a dog sniff conducted during a lawful traffic stop

does not violate the Fourth Amendment’s proscription of 

unreasonable seizures. This case presents the question

whether the Fourth Amendment tolerates a dog sniff

conducted after completion of a traffic stop. We hold that 

a police stop exceeding the time needed to handle the

matter for which the stop was made violates the Constitution’s shield against unreasonable seizures. A seizure 

justified only by a police-observed traffic violation, therefore, “become[s] unlawful if it is prolonged beyond the time 

reasonably required to complete th[e] mission” of issuing a

ticket for the violation. Id., at 407. The Court so recognized in Caballes, and we adhere to the line drawn in that 

decision. 

I 

Just after midnight on March 27, 2012, police officer

Morgan Struble observed a Mercury Mountaineer veer 

slowly onto the shoulder of Nebraska State Highway 275 

for one or two seconds and then jerk back onto the road. 
 

2 RODRIGUEZ v. UNITED STATES 

Opinion of the Court 

Nebraska law prohibits driving on highway shoulders, see

Neb. Rev. Stat. §60–6,142 (2010), and on that basis, Struble pulled the Mountaineer over at 12:06 a.m. Struble is a

K–9 officer with the Valley Police Department in Nebraska, and his dog Floyd was in his patrol car that night. 

Two men were in the Mountaineer: the driver, Dennys

Rodriguez, and a front-seat passenger, Scott Pollman.

Struble approached the Mountaineer on the passenger’s 

side. After Rodriguez identified himself, Struble asked 

him why he had driven onto the shoulder. Rodriguez

replied that he had swerved to avoid a pothole. Struble 

then gathered Rodriguez’s license, registration, and proof

of insurance, and asked Rodriguez to accompany him to 

the patrol car. Rodriguez asked if he was required to do

so, and Struble answered that he was not. Rodriguez 

decided to wait in his own vehicle. 

After running a records check on Rodriguez, Struble

returned to the Mountaineer. Struble asked passenger

Pollman for his driver’s license and began to question him

about where the two men were coming from and where

they were going. Pollman replied that they had traveled

to Omaha, Nebraska, to look at a Ford Mustang that was 

for sale and that they were returning to Norfolk, Nebraska. Struble returned again to his patrol car, where he

completed a records check on Pollman, and called for a

second officer. Struble then began writing a warning

ticket for Rodriguez for driving on the shoulder of the

road. 

Struble returned to Rodriguez’s vehicle a third time to

issue the written warning. By 12:27 or 12:28 a.m., Struble 

had finished explaining the warning to Rodriguez, and

had given back to Rodriguez and Pollman the documents 

obtained from them. As Struble later testified, at that 

point, Rodriguez and Pollman “had all their documents

back and a copy of the written warning. I got all the

reason[s] for the stop out of the way[,] . . . took care of all 
Cite as: 575 U. S. ____ (2015) 3 

Opinion of the Court 

the business.” App. 70.

Nevertheless, Struble did not consider Rodriguez “free

to leave.” Id., at 69–70. Although justification for the 

traffic stop was “out of the way,” id., at 70, Struble asked 

for permission to walk his dog around Rodriguez’s vehicle. 

Rodriguez said no. Struble then instructed Rodriguez to

turn off the ignition, exit the vehicle, and stand in front of 

the patrol car to wait for the second officer. Rodriguez 

complied. At 12:33 a.m., a deputy sheriff arrived. Struble 

retrieved his dog and led him twice around the Mountaineer. The dog alerted to the presence of drugs halfway

through Struble’s second pass. All told, seven or eight

minutes had elapsed from the time Struble issued the 

written warning until the dog indicated the presence of 

drugs. A search of the vehicle revealed a large bag of

methamphetamine.

Rodriguez was indicted in the United States District 

Court for the District of Nebraska on one count of possession with intent to distribute 50 grams or more of methamphetamine, in violation of 21 U. S. C. §§841(a)(1) and 

(b)(1). He moved to suppress the evidence seized from his 

car on the ground, among others, that Struble had prolonged the traffic stop without reasonable suspicion in 

order to conduct the dog sniff. 

After receiving evidence, a Magistrate Judge recommended that the motion be denied. The Magistrate Judge

found no probable cause to search the vehicle independent 

of the dog alert. App. 100 (apart from “information given

by the dog,” “Officer Struble had [no]thing other than a

rather large hunch”). He further found that no reasonable 

suspicion supported the detention once Struble issued the

written warning. He concluded, however, that under 

Eighth Circuit precedent, extension of the stop by “seven

to eight minutes” for the dog sniff was only a de minimis 

intrusion on Rodriguez’s Fourth Amendment rights and

was therefore permissible. 
 

4 RODRIGUEZ v. UNITED STATES 

Opinion of the Court 

The District Court adopted the Magistrate Judge’s

factual findings and legal conclusions and denied Rodriguez’s motion to suppress. The court noted that, in the 

Eighth Circuit, “dog sniffs that occur within a short time

following the completion of a traffic stop are not constitutionally prohibited if they constitute only de minimis

intrusions.” App. 114 (quoting United States v. Alexander, 

448 F. 3d 1014, 1016 (CA8 2006)). The court thus agreed 

with the Magistrate Judge that the “7 to 10 minutes”

added to the stop by the dog sniff “was not of constitutional significance.” App. 114. Impelled by that decision, 

Rodriguez entered a conditional guilty plea and was sentenced to five years in prison.

The Eighth Circuit affirmed. The “seven- or eightminute delay” in this case, the opinion noted, resembled

delays that the court had previously ranked as permissible. 741 F. 3d 905, 907 (2014). The Court of Appeals thus

ruled that the delay here constituted an acceptable “de 

minimis intrusion on Rodriguez’s personal liberty.” Id., at 

908. Given that ruling, the court declined to reach the 

question whether Struble had reasonable suspicion to

continue Rodriguez’s detention after issuing the written 

warning.

We granted certiorari to resolve a division among lower 

courts on the question whether police routinely may extend an otherwise-completed traffic stop, absent reasonable suspicion, in order to conduct a dog sniff. 573 U. S. ___ 

(2014). Compare, e.g., United States v. Morgan, 270 F. 3d 

625, 632 (CA8 2001) (postcompletion delay of “well under 

ten minutes” permissible), with, e.g., State v. Baker, 2010 

UT 18, ¶13, 229 P. 3d 650, 658 (2010) (“[W]ithout additional reasonable suspicion, the officer must allow the 

seized person to depart once the purpose of the stop has 

concluded.”). 
 

 

Cite as: 575 U. S. ____ (2015) 5 

Opinion of the Court 

II 

A seizure for a traffic violation justifies a police investigation of that violation. “[A] relatively brief encounter,” a 

routine traffic stop is “more analogous to a so-called ‘Terry 

stop’ . . . than to a formal arrest.” Knowles v. Iowa, 525 

U. S. 113, 117 (1998) (quoting Berkemer v. McCarty, 468 

U. S. 420, 439 (1984), in turn citing Terry v. Ohio, 392 

U. S. 1 (1968)). See also Arizona v. Johnson, 555 U. S. 

323, 330 (2009). Like a Terry stop, the tolerable duration 

of police inquiries in the traffic-stop context is determined

by the seizure’s “mission”—to address the traffic violation

that warranted the stop, Caballes, 543 U. S., at 407, and 

attend to related safety concerns, infra, at 6–7. See also 

United States v. Sharpe, 470 U. S. 675, 685 (1985); Florida 

v. Royer, 460 U. S. 491, 500 (1983) (plurality opinion) 

(“The scope of the detention must be carefully tailored to

its underlying justification.”). Because addressing the

infraction is the purpose of the stop, it may “last no longer 

than is necessary to effectuate th[at] purpose.” Ibid. See 

also Caballes, 543 U. S., at 407. Authority for the seizure 

thus ends when tasks tied to the traffic infraction are—or 

reasonably should have been—completed. See Sharpe, 

470 U. S., at 686 (in determining the reasonable duration

of a stop, “it [is] appropriate to examine whether the police

diligently pursued [the] investigation”).

Our decisions in Caballes and Johnson heed these constraints. In both cases, we concluded that the Fourth 

Amendment tolerated certain unrelated investigations

that did not lengthen the roadside detention. Johnson, 

555 U. S., at 327–328 (questioning); Caballes, 543 U. S., at 

406, 408 (dog sniff). In Caballes, however, we cautioned 

that a traffic stop “can become unlawful if it is prolonged 

beyond the time reasonably required to complete th[e] 

mission” of issuing a warning ticket. 543 U. S., at 407. 

And we repeated that admonition in Johnson: The seizure 

remains lawful only “so long as [unrelated] inquiries do 
 

 

6 RODRIGUEZ v. UNITED STATES 

Opinion of the Court 

not measurably extend the duration of the stop.” 555 

U. S., at 333. See also Muehler v. Mena, 544 U. S. 93, 101 

(2005) (because unrelated inquiries did not “exten[d] the 

time [petitioner] was detained[,] . . . no additional Fourth

Amendment justification . . . was required”). An officer, in 

other words, may conduct certain unrelated checks during

an otherwise lawful traffic stop. But contrary to JUSTICE 

ALITO’s suggestion, post, at 4, n. 2, he may not do so in a

way that prolongs the stop, absent the reasonable suspicion ordinarily demanded to justify detaining an individual. But see post, at 1–2 (ALITO, J., dissenting) (premising 

opinion on the dissent’s own finding of “reasonable suspicion,” although the District Court reached the opposite 

conclusion, and the Court of Appeals declined to consider

the issue).

Beyond determining whether to issue a traffic ticket, an

officer’s mission includes “ordinary inquiries incident to

[the traffic] stop.” Caballes, 543 U. S., at 408. Typically

such inquiries involve checking the driver’s license, determining whether there are outstanding warrants 

against the driver, and inspecting the automobile’s registration and proof of insurance. See Delaware v. Prouse, 

440 U. S. 648, 658–660 (1979). See also 4 W. LaFave, 

Search and Seizure §9.3(c), pp. 507–517 (5th ed. 2012). 

These checks serve the same objective as enforcement of 

the traffic code: ensuring that vehicles on the road are 

operated safely and responsibly. See Prouse, 440 U. S., at 

658–659; LaFave, Search and Seizure §9.3(c), at 516 (A 

“warrant check makes it possible to determine whether

the apparent traffic violator is wanted for one or more

previous traffic offenses.”).

A dog sniff, by contrast, is a measure aimed at “detect[ing] evidence of ordinary criminal wrongdoing.” 

Indianapolis v. Edmond, 531 U. S. 32, 40–41 (2000). See 

also Florida v. Jardines, 569 U. S. 1, ___–___ (2013) (slip 

op., at 7–8). Candidly, the Government acknowledged at 
 

 

Cite as: 575 U. S. ____ (2015) 7 

Opinion of the Court 

oral argument that a dog sniff, unlike the routine

measures just mentioned, is not an ordinary incident of a

traffic stop. See Tr. of Oral Arg. 33. Lacking the same

close connection to roadway safety as the ordinary inquiries, a dog sniff is not fairly characterized as part of the

officer’s traffic mission. 

In advancing its de minimis rule, the Eighth Circuit 

relied heavily on our decision in Pennsylvania v. Mimms, 

434 U. S. 106 (1977) (per curiam). See United States v. 

$404,905.00 in U. S. Currency, 182 F. 3d 643, 649 (CA8 

1999). In Mimms, we reasoned that the government’s 

“legitimate and weighty” interest in officer safety outweighs the “de minimis” additional intrusion of requiring

a driver, already lawfully stopped, to exit the vehicle. 434 

U. S., at 110–111. See also Maryland v. Wilson, 519 U. S. 

408, 413–415 (1997) (passengers may be required to exit 

vehicle stopped for traffic violation). The Eighth Circuit, 

echoed in JUSTICE THOMAS’s dissent, believed that the 

imposition here similarly could be offset by the Government’s “strong interest in interdicting the flow of illegal 

drugs along the nation’s highways.” $404,905.00 in U. S. 

Currency, 182 F. 3d, at 649; see post, at 9. 

Unlike a general interest in criminal enforcement, 

however, the government’s officer safety interest stems 

from the mission of the stop itself. Traffic stops are “especially fraught with danger to police officers,” Johnson, 555 

U. S., at 330 (internal quotation marks omitted), so an 

officer may need to take certain negligibly burdensome 

precautions in order to complete his mission safely. Cf. 

United States v. Holt, 264 F. 3d 1215, 1221–1222 (CA10

2001) (en banc) (recognizing officer safety justification for 

criminal record and outstanding warrant checks), abrogated on other grounds as recognized in United States v. 

Stewart, 473 F. 3d 1265, 1269 (CA10 2007). On-scene 

investigation into other crimes, however, detours from

that mission. See supra, at 6–7. So too do safety precau­
 

 

8 RODRIGUEZ v. UNITED STATES 

Opinion of the Court 

tions taken in order to facilitate such detours. But cf. post,

at 2–3 (ALITO, J., dissenting). Thus, even assuming that 

the imposition here was no more intrusive than the exit 

order in Mimms, the dog sniff could not be justified on the 

same basis. Highway and officer safety are interests

different in kind from the Government’s endeavor to detect crime in general or drug trafficking in particular. 

The Government argues that an officer may “incremental[ly]” prolong a stop to conduct a dog sniff so long as the

officer is reasonably diligent in pursuing the traffic-related 

purpose of the stop, and the overall duration of the stop 

remains reasonable in relation to the duration of other 

traffic stops involving similar circumstances. Brief for 

United States 36–39. The Government’s argument, in

effect, is that by completing all traffic-related tasks expeditiously, an officer can earn bonus time to pursue an

unrelated criminal investigation. See also post, at 2–5 

(THOMAS, J., dissenting) (embracing the Government’s

argument). The reasonableness of a seizure, however, 

depends on what the police in fact do. See Knowles, 525 

U. S., at 115–117. In this regard, the Government 

acknowledges that “an officer always has to be reasonably 

diligent.” Tr. of Oral Arg. 49. How could diligence be 

gauged other than by noting what the officer actually did 

and how he did it? If an officer can complete traffic-based

inquiries expeditiously, then that is the amount of “time 

reasonably required to complete [the stop’s] mission.” 

Caballes, 543 U. S., at 407. As we said in Caballes and 

reiterate today, a traffic stop “prolonged beyond” that

point is “unlawful.” Ibid. The critical question, then, is 

not whether the dog sniff occurs before or after the officer 

issues a ticket, as JUSTICE ALITO supposes, post, at 2–4, 

but whether conducting the sniff “prolongs”—i.e., adds 

time to—“the stop,” supra, at 6. 
 

 

 

Cite as: 575 U. S. ____ (2015) 9 

Opinion of the Court 

III 

The Magistrate Judge found that detention for the dog 

sniff in this case was not independently supported by

individualized suspicion, see App. 100, and the District 

Court adopted the Magistrate Judge’s findings, see id., at 

112–113. The Court of Appeals, however, did not review 

that determination. But see post, at 1, 10–12 (THOMAS, J., 

dissenting) (resolving the issue, nevermind that the Court 

of Appeals left it unaddressed); post, at 1–2 (ALITO, J., 

dissenting) (upbraiding the Court for addressing the sole 

issue decided by the Court of Appeals and characterizing 

the Court’s answer as “unnecessary” because the Court, 

instead, should have decided an issue the Court of Appeals 

did not decide). The question whether reasonable suspicion of criminal activity justified detaining Rodriguez 

beyond completion of the traffic infraction investigation, 

therefore, remains open for Eighth Circuit consideration 

on remand. 

* * * 

For the reasons stated, the judgment of the United 

States Court of Appeals for the Eighth Circuit is vacated,

and the case is remanded for further proceedings consistent with this opinion. 

It is so ordered. 
_________________ 

_________________ 

Cite as: 575 U. S. ____ (2015) 1 

KENNEDY, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 13–9972 

DENNYS RODRIGUEZ, PETITIONER v.

 UNITED STATES
 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE EIGHTH CIRCUIT
 

[April 21, 2015] 

JUSTICE KENNEDY, dissenting. 

My join in JUSTICE THOMAS’ dissenting opinion does not

extend to Part III. Although the issue discussed in that 

Part was argued here, the Court of Appeals has not addressed that aspect of the case in any detail. In my view 

the better course would be to allow that court to do so in 

the first instance. 
_________________ 

_________________ 

 

Cite as: 575 U. S. ____ (2015) 1 

THOMAS, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 13–9972 

DENNYS RODRIGUEZ, PETITIONER v.

 UNITED STATES
 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE EIGHTH CIRCUIT
 

[April 21, 2015] 

JUSTICE THOMAS, with whom JUSTICE ALITO joins, and

with whom JUSTICE KENNEDY joins as to all but Part III, 

dissenting. 

Ten years ago, we explained that “conducting a dog sniff

[does] not change the character of a traffic stop that is

lawful at its inception and otherwise executed in a reasonable manner.” Illinois v. Caballes, 543 U. S. 405, 408 

(2005). The only question here is whether an officer executed a stop in a reasonable manner when he waited to

conduct a dog sniff until after he had given the driver a

written warning and a backup unit had arrived, bringing 

the overall duration of the stop to 29 minutes. Because 

the stop was reasonably executed, no Fourth Amendment 

violation occurred. The Court’s holding to the contrary

cannot be reconciled with our decision in Caballes or a 

number of common police practices. It was also unnecessary, as the officer possessed reasonable suspicion to 

continue to hold the driver to conduct the dog sniff. I 

respectfully dissent. 

I 

The Fourth Amendment protects “[t]he right of the

people to be secure in their persons, houses, papers, and

effects, against unreasonable searches and seizures.”

U. S. Const., Amdt. 4. As the text indicates, and as we 
 

2 RODRIGUEZ v. UNITED STATES 

THOMAS, J., dissenting 

have repeatedly confirmed, “the ultimate touchstone of the 

Fourth Amendment is ‘reasonableness.’” Brigham City v. 

Stuart, 547 U. S. 398, 403 (2006). We have defined reasonableness “in objective terms by examining the totality 

of the circumstances,” Ohio v. Robinette, 519 U. S. 33, 39 

(1996), and by considering “the traditional protections

against unreasonable searches and seizures afforded by 

the common law at the time of the framing,” Atwater v. 

Lago Vista, 532 U. S. 318, 326 (2001) (internal quotation 

marks omitted). When traditional protections have not

provided a definitive answer, our precedents have “analyzed a search or seizure in light of traditional standards

of reasonableness by assessing, on the one hand, the degree to which it intrudes upon an individual’s privacy and,

on the other, the degree to which it is needed for the promotion of legitimate governmental interests.” Virginia v. 

Moore, 553 U. S. 164, 171 (2008) (internal quotation

marks omitted). 

Although a traffic stop “constitutes a ‘seizure’ of ‘persons’ within the meaning of [the Fourth Amendment],”

such a seizure is constitutionally “reasonable where the

police have probable cause to believe that a traffic violation has occurred.” Whren v. United States, 517 U. S. 806, 

809–810 (1996). But “a seizure that is lawful at its inception can violate the Fourth Amendment if its manner of 

execution unreasonably infringes interests protected by

the Constitution.” Caballes, supra, at 407. 

Because Rodriguez does not dispute that Officer Struble

had probable cause to stop him, the only question is 

whether the stop was otherwise executed in a reasonable 

manner. See Brief for Appellant in No. 13–1176 (CA8), 

p. 4, n. 2. I easily conclude that it was. Approximately 29

minutes passed from the time Officer Struble stopped

Rodriguez until his narcotics-detection dog alerted to the 

presence of drugs. That amount of time is hardly out of 

the ordinary for a traffic stop by a single officer of a vehi-
Cite as: 575 U. S. ____ (2015) 3 

THOMAS, J., dissenting 

cle containing multiple occupants even when no dog sniff 

is involved. See, e.g., United States v. Ellis, 497 F. 3d 606 

(CA6 2007) (22 minutes); United States v. Barragan, 379 

F. 3d 524 (CA8 2004) (approximately 30 minutes). During

that time, Officer Struble conducted the ordinary activities

of a traffic stop—he approached the vehicle, questioned 

Rodriguez about the observed violation, asked Pollman 

about their travel plans, ran serial warrant checks on

Rodriguez and Pollman, and issued a written warning to

Rodriguez. And when he decided to conduct a dog sniff, he

took the precaution of calling for backup out of concern for 

his safety. See 741 F. 3d 905, 907 (CA8 2014); see also 

Pennsylvania v. Mimms, 434 U. S. 106, 110 (1977) (per 

curiam) (officer safety is a “legitimate and weighty” concern relevant to reasonableness).

As Caballes makes clear, the fact that Officer Struble 

waited until after he gave Rodriguez the warning to conduct the dog sniff does not alter this analysis. Because 

“the use of a well-trained narcotics-detection dog . . . generally does not implicate legitimate privacy interests,” 543 

U. S., at 409, “conducting a dog sniff would not change the 

character of a traffic stop that is lawful at its inception

and otherwise executed in a reasonable manner,” id., at 

408. The stop here was “lawful at its inception and otherwise executed in a reasonable manner.” Ibid. As in Caballes, “conducting a dog sniff [did] not change the character of [the] traffic stop,” ibid., and thus no Fourth 

Amendment violation occurred. 

II 

Rather than adhere to the reasonableness requirement 

that we have repeatedly characterized as the “touchstone 

of the Fourth Amendment,” Brigham City, supra, at 403, 

the majority constructed a test of its own that is inconsistent with our precedents. 
 

4 RODRIGUEZ v. UNITED STATES 

THOMAS, J., dissenting
 

A 

The majority’s rule requires a traffic stop to “en[d] when

tasks tied to the traffic infraction are—or reasonably

should have been—completed.” Ante, at 5. “If an officer 

can complete traffic-based inquiries expeditiously, then 

that is the amount of time reasonably required to complete

the stop’s mission” and he may hold the individual no

longer. Ante, at 8 (internal quotation marks and alterations omitted). The majority’s rule thus imposes a oneway ratchet for constitutional protection linked to the

characteristics of the individual officer conducting the

stop: If a driver is stopped by a particularly efficient officer, then he will be entitled to be released from the traffic stop after a shorter period of time than a driver stopped 

by a less efficient officer. Similarly, if a driver is stopped 

by an officer with access to technology that can shorten a 

records check, then he will be entitled to be released from 

the stop after a shorter period of time than an individual 

stopped by an officer without access to such technology. 

I “cannot accept that the search and seizure protections

of the Fourth Amendment are so variable and can be made 

to turn upon such trivialities.” Whren, 517 U. S., at 815 

(citations omitted). We have repeatedly explained that the

reasonableness inquiry must not hinge on the characteristics of the individual officer conducting the seizure. We 

have held, for example, that an officer’s state of mind

“does not invalidate [an] action taken as long as the circumstances, viewed objectively, justify that action.” Id., at 

813 (internal quotation marks omitted). We have spurned

theories that would make the Fourth Amendment “change

with local law enforcement practices.” Moore, supra, at 

172. And we have rejected a rule that would require the

offense establishing probable cause to be “closely related 

to” the offense identified by the arresting officer, as such a 

rule would make “the constitutionality of an arrest . . . 

vary from place to place and from time to time, depending 
Cite as: 575 U. S. ____ (2015) 5 

THOMAS, J., dissenting 

on whether the arresting officer states the reason for the 

detention and, if so, whether he correctly identifies a 

general class of offense for which probable cause exists.” 

Devenpeck v. Alford, 543 U. S. 146, 154 (2004) (internal 

quotation marks and citation omitted). In Devenpeck, a 

unanimous Court explained: “An arrest made by a knowledgeable, veteran officer would be valid, whereas an arrest

made by a rookie in precisely the same circumstances 

would not. We see no reason to ascribe to the Fourth 

Amendment such arbitrarily variable protection.” Ibid. 

The majority’s logic would produce similarly arbitrary

results. Under its reasoning, a traffic stop made by a 

rookie could be executed in a reasonable manner, whereas 

the same traffic stop made by a knowledgeable, veteran 

officer in precisely the same circumstances might not, if in 

fact his knowledge and experience made him capable of 

completing the stop faster. We have long rejected interpretations of the Fourth Amendment that would produce 

such haphazard results, and I see no reason to depart from

our consistent practice today. 

B 

As if that were not enough, the majority also limits the

duration of the stop to the time it takes the officer to

complete a narrow category of “traffic-based inquiries.” 

Ante, at 8. According to the majority, these inquiries

include those that “serve the same objective as enforcement of the traffic code: ensuring that vehicles on the road 

are operated safely and responsibly.” Ante, at 6. Inquiries 

directed to “detecting evidence of ordinary criminal 

wrongdoing” are not traffic-related inquiries and thus

cannot count toward the overall duration of the stop. Ibid. 

(internal quotation marks and alteration omitted).

The combination of that definition of traffic-related 

inquiries with the majority’s officer-specific durational 

limit produces a result demonstrably at odds with our 
 

 

6 RODRIGUEZ v. UNITED STATES 

THOMAS, J., dissenting 

decision in Caballes. Caballes expressly anticipated that a 

traffic stop could be reasonably prolonged for officers to 

engage in a dog sniff. We explained that no Fourth

Amendment violation had occurred in Caballes, where the 

“duration of the stop . . . was entirely justified by the

traffic offense and the ordinary inquiries incident to such

a stop,” but suggested a different result might attend a 

case “involving a dog sniff that occurred during an unreasonably prolonged traffic stop.” 543 U. S., at 407–408 

(emphasis added). The dividing line was whether the

overall duration of the stop exceeded “the time reasonably 

required to complete th[e] mission,” id., at 407, not, as the 

majority suggests, whether the duration of the stop “in 

fact” exceeded the time necessary to complete the trafficrelated inquiries, ante, at 8. 

The majority’s approach draws an artificial line between 

dog sniffs and other common police practices. The lower 

courts have routinely confirmed that warrant checks are a 

constitutionally permissible part of a traffic stop, see, e.g., 

United States v. Simmons, 172 F. 3d 775, 778 (CA11 

1999); United States v. Mendez, 118 F. 3d 1426, 1429 

(CA10 1997); United States v. Shabazz, 993 F. 2d 431, 437 

(CA5 1993), and the majority confirms that it finds no

fault in these measures, ante, at 6. Yet its reasoning 

suggests the opposite. Such warrant checks look more like 

they are directed to “detecting evidence of ordinary criminal wrongdoing” than to “ensuring that vehicles on the 

road are operated safely and responsibly.” Ante, at 6 

(internal quotation marks and alteration omitted). Perhaps one could argue that the existence of an outstanding 

warrant might make a driver less likely to operate his 

vehicle safely and responsibly on the road, but the same 

could be said about a driver in possession of contraband.

A driver confronted by the police in either case might try 

to flee or become violent toward the officer. But under the 

majority’s analysis, a dog sniff, which is directed at uncov-
 

Cite as: 575 U. S. ____ (2015) 7 

THOMAS, J., dissenting 

ering that problem, is not treated as a traffic-based inquiry. Warrant checks, arguably, should fare no better.

The majority suggests that a warrant check is an ordinary 

inquiry incident to a traffic stop because it can be used “‘to 

determine whether the apparent traffic violator is wanted 

for one or more previous traffic offenses.’” Ante, at 6 

(quoting 4 W. LaFave, Search and Seizure §9.3(c), p. 516 

(5th ed. 2012)). But as the very treatise on which the 

majority relies notes, such checks are a “manifest[ation of]

the ‘war on drugs’ motivation so often underlying [routine 

traffic] stops,” and thus are very much like the dog sniff in

this case. Id., §9.3(c), at 507–508.

Investigative questioning rests on the same basis as the 

dog sniff. “Asking questions is an essential part of police

investigations.” Hiibel v. Sixth Judicial Dist. Court of 

Nev., Humboldt Cty., 542 U. S. 177, 185 (2004). And the 

lower courts have routinely upheld such questioning during routine traffic stops. See, e.g., United States v. Rivera, 

570 F. 3d 1009, 1013 (CA8 2009); United States v. Childs, 

277 F. 3d 947, 953–954 (CA7 2002). The majority’s reasoning appears to allow officers to engage in some questioning aimed at detecting evidence of ordinary criminal 

wrongdoing. Ante, at 5. But it is hard to see how such 

inquiries fall within the “seizure’s ‘mission’ [of] address[ing] the traffic violation that warranted the stop,” or

“attend[ing] to related safety concerns.” Ibid. Its reasoning appears to come down to the principle that dogs are 

different. 

C 

On a more fundamental level, the majority’s inquiry 

elides the distinction between traffic stops based on probable cause and those based on reasonable suspicion. 

Probable cause is the “traditional justification” for the 

seizure of a person. Whren, 517 U. S., at 817 (emphasis

deleted); see also Dunaway v. New York, 442 U. S. 200, 
 

 

8 RODRIGUEZ v. UNITED STATES 

THOMAS, J., dissenting 

207–208 (1979). This Court created an exception to that 

rule in Terry v. Ohio, 392 U. S. 1 (1968), permitting “police 

officers who suspect criminal activity to make limited

intrusions on an individual’s personal security based on

less than probable cause,” Michigan v. Summers, 452 U. S. 

692, 698 (1981). Reasonable suspicion is the justification 

for such seizures. Prado Navarette v. California, 572 U. S. 

___, ___ (2014) (slip op., at 3). 

Traffic stops can be initiated based on probable cause or

reasonable suspicion. Although the Court has commented 

that a routine traffic stop is “more analogous to a so-called 

‘Terry stop’ than to a formal arrest,” it has rejected the 

notion “that a traffic stop supported by probable cause

may not exceed the bounds set by the Fourth Amendment

on the scope of a Terry stop.” Berkemer v. McCarty, 468 

U. S. 420, 439, and n. 29 (1984) (citation omitted).

Although all traffic stops must be executed reasonably,

our precedents make clear that traffic stops justified by 

reasonable suspicion are subject to additional limitations

that those justified by probable cause are not. A traffic 

stop based on reasonable suspicion, like all Terry stops,

must be “justified at its inception” and “reasonably related 

in scope to the circumstances which justified the interference in the first place.” Hiibel, 542 U. S., at 185 (internal 

quotation marks omitted). It also “cannot continue for an 

excessive period of time or resemble a traditional arrest.” 

Id., at 185–186 (citation omitted). By contrast, a stop 

based on probable cause affords an officer considerably 

more leeway. In such seizures, an officer may engage in a

warrantless arrest of the driver, Atwater, 532 U. S., at 

354, a warrantless search incident to arrest of the driver, 

Riley v. California, 573 U. S. ___, ___ (2014) (slip op., at 5),

and a warrantless search incident to arrest of the vehicle 

if it is reasonable to believe evidence relevant to the crime 

of arrest might be found there, Arizona v. Gant, 556 U. S. 

332, 335 (2009). 
Cite as: 575 U. S. ____ (2015) 9 

THOMAS, J., dissenting 

The majority casually tosses this distinction aside. It 

asserts that the traffic stop in this case, which was undisputedly initiated on the basis of probable cause, can last

no longer than is in fact necessary to effectuate the mission of the stop. Ante, at 8. And, it assumes that the 

mission of the stop was merely to write a traffic ticket,

rather than to consider making a custodial arrest. Ante, 

at 5. In support of that durational requirement, it relies 

primarily on cases involving Terry stops. See ante, at 5–7 

(citing Arizona v. Johnson, 555 U. S. 323 (2009) (analyzing 

“stop and frisk” of passenger in a vehicle temporarily 

seized for a traffic violation); United States v. Sharpe, 470 

U. S. 675 (1985) (analyzing seizure of individuals based on 

suspicion of marijuana trafficking); Florida v. Royer, 460 

U. S. 491 (1983) (plurality opinion) (analyzing seizure of

man walking through airport on suspicion of narcotics

activity)). 

The only case involving a traffic stop based on probable

cause that the majority cites for its rule is Caballes. But, 

that decision provides no support for today’s restructuring

of our Fourth Amendment jurisprudence. In Caballes, the 

Court made clear that, in the context of a traffic stop

supported by probable cause, “a dog sniff would not change

the character of a traffic stop that is lawful at its inception

and otherwise executed in a reasonable manner.” 543 

U. S., at 408. To be sure, the dissent in Caballes would 

have “appl[ied] Terry’s reasonable-relation test . . . to 

determine whether the canine sniff impermissibly expanded the scope of the initially valid seizure of Caballes.” 

Id., at 420 (GINSBURG, J., dissenting). But even it conceded 

that the Caballes majority had “implicitly [rejected] the 

application of Terry to a traffic stop converted, by calling 

in a dog, to a drug search.” Id., at 421. 

By strictly limiting the tasks that define the durational 

scope of the traffic stop, the majority accomplishes today

what the Caballes dissent could not: strictly limiting the 
 

 

 

10 RODRIGUEZ v. UNITED STATES 

THOMAS, J., dissenting 

scope of an officer’s activities during a traffic stop justified

by probable cause. In doing so, it renders the difference 

between probable cause and reasonable suspicion virtually 

meaningless in this context. That shift is supported neither by the Fourth Amendment nor by our precedents

interpreting it. And, it results in a constitutional framework that lacks predictability. Had Officer Struble arrested, handcuffed, and taken Rodriguez to the police 

station for his traffic violation, he would have complied 

with the Fourth Amendment. See Atwater, supra, at 354– 

355. But because he made Rodriguez wait for seven or 

eight extra minutes until a dog arrived, he evidently 

committed a constitutional violation. Such a view of the 

Fourth Amendment makes little sense. 

III 

Today’s revision of our Fourth Amendment jurisprudence was also entirely unnecessary. Rodriguez suffered 

no Fourth Amendment violation here for an entirely independent reason: Officer Struble had reasonable suspicion

to continue to hold him for investigative purposes. Our 

precedents make clear that the Fourth Amendment permits an officer to conduct an investigative traffic stop 

when that officer has “a particularized and objective basis 

for suspecting the particular person stopped of criminal 

activity.” Prado Navarette, 572 U. S., at ___ (slip op., at 3) 

(internal quotation marks omitted). Reasonable suspicion

is determined by looking at “the whole picture,” ibid., 

taking into account “the factual and practical considerations of everyday life on which reasonable and prudent 

men, not legal technicians, act,” Ornelas v. United States, 

517 U. S. 690, 695 (1996) (internal quotation marks 

omitted).

Officer Struble testified that he first became suspicious 

that Rodriguez was engaged in criminal activity for a 

number of reasons. When he approached the vehicle, he 
Cite as: 575 U. S. ____ (2015) 11 

THOMAS, J., dissenting 

smelled an “overwhelming odor of air freshener coming 

from the vehicle,” which is, in his experience, “a common 

attempt to conceal an odor that [people] don’t want . . . to 

be smelled by the police.” App. 20–21. He also observed, 

upon approaching the front window on the passenger side 

of the vehicle, that Rodriguez’s passenger, Scott Pollman,

appeared nervous. Pollman pulled his hat down low,

puffed nervously on a cigarette, and refused to make eye 

contact with him. The officer thought he was “more nervous than your typical passenger” who “do[esn’t] have

anything to worry about because [t]hey didn’t commit a

[traffic] violation.” Id., at 34. 

Officer Struble’s interactions with the vehicle’s occupants only increased his suspicions. When he asked Rodriguez why he had driven onto the shoulder, Rodriguez 

claimed that he swerved to avoid a pothole. But that story

could not be squared with Officer Struble’s observation of 

the vehicle slowly driving off the road before being jerked 

back onto it. And when Officer Struble asked Pollman 

where they were coming from and where they were going, 

Pollman told him they were traveling from Omaha, Nebraska, back to Norfolk, Nebraska, after looking at a

vehicle they were considering purchasing. Pollman told 

the officer that he had neither seen pictures of the vehicle

nor confirmed title before the trip. As Officer Struble 

explained, it “seemed suspicious” to him “to drive . . .

approximately two hours . . . late at night to see a vehicle 

sight unseen to possibly buy it,” id., at 26, and to go from

Norfolk to Omaha to look at it because “[u]sually people

leave Omaha to go get vehicles, not the other way around” 

due to higher Omaha taxes, id., at 65. 

These facts, taken together, easily meet our standard for 

reasonable suspicion. “[N]ervous, evasive behavior is a

pertinent factor in determining reasonable suspicion,” 

Illinois v. Wardlow, 528 U. S. 119, 124 (2000), and both

vehicle occupants were engaged in such conduct. The 
 

 

12 RODRIGUEZ v. UNITED STATES 

THOMAS, J., dissenting 

officer also recognized heavy use of air freshener, which, in 

his experience, indicated the presence of contraband in the 

vehicle. “[C]ommonsense judgments and inferences about 

human behavior” further support the officer’s conclusion 

that Pollman’s story about their trip was likely a cover 

story for illegal activity. Id., at 125. Taking into account

all the relevant facts, Officer Struble possessed reasonable 

suspicion of criminal activity to conduct the dog sniff. 

Rodriguez contends that reasonable suspicion cannot 

exist because each of the actions giving rise to the officer’s

suspicions could be entirely innocent, but our cases easily 

dispose of that argument. Acts that, by themselves, might 

be innocent can, when taken together, give rise to reasonable suspicion. United States v. Arvizu, 534 U. S. 266, 

274–275 (2002). Terry is a classic example, as it involved

two individuals repeatedly walking back and forth, looking 

into a store window, and conferring with one another as

well as with a third man. 392 U. S., at 6. The Court 

reasoned that this “series of acts, each of them perhaps 

innocent in itself, . . . together warranted further investigation,” id., at 22, and it has reiterated that analysis in a 

number of cases, see, e.g., Arvizu, supra, at 277; United 

States v. Sokolow, 490 U. S. 1, 9–10 (1989). This one is no 

different. 

* * * 

I would conclude that the police did not violate the

Fourth Amendment here. Officer Struble possessed probable cause to stop Rodriguez for driving on the shoulder, 

and he executed the subsequent stop in a reasonable 

manner. Our decision in Caballes requires no more. The 

majority’s holding to the contrary is irreconcilable with 

Caballes and a number of other routine police practices,

distorts the distinction between traffic stops justified by

probable cause and those justified by reasonable suspicion,

and abandons reasonableness as the touchstone of the 

Fourth Amendment. I respectfully dissent. 
_________________ 

_________________ 

 

 

Cite as: 575 U. S. ____ (2015) 1 

ALITO, J., dissenting 

SUPREME COURT OF THE UNITED STATES 

No. 13–9972 

DENNYS RODRIGUEZ, PETITIONER v.

 UNITED STATES
 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE EIGHTH CIRCUIT
 

[April 21, 2015] 

JUSTICE ALITO, dissenting. 

This is an unnecessary,1 impractical, and arbitrary 

decision. It addresses a purely hypothetical question:

whether the traffic stop in this case would be unreasonable if the police officer, prior to leading a drug-sniffing dog 

around the exterior of petitioner’s car, did not already

have reasonable suspicion that the car contained drugs.

In fact, however, the police officer did have reasonable 

suspicion, and, as a result, the officer was justified in

detaining the occupants for the short period of time (seven 

or eight minutes) that is at issue.

The relevant facts are not in dispute. Officer Struble, 

who made the stop, was the only witness at the suppression hearing, and his testimony about what happened was

not challenged. Defense counsel argued that the facts

recounted by Officer Struble were insufficient to establish

reasonable suspicion, but defense counsel did not dispute

those facts or attack the officer’s credibility. Similarly, the

Magistrate Judge who conducted the hearing did not 

question the officer’s credibility. And as JUSTICE 

THOMAS’s opinion shows, the facts recounted by Officer 

Struble “easily meet our standard for reasonable suspicion.” Ante, at 11 (dissenting opinion); see also, e.g., United 

—————— 

1See Brief in Opposition 11–14. 
 

2 RODRIGUEZ v. UNITED STATES 

ALITO, J., dissenting 

States v. Carpenter, 462 F. 3d 981, 986–987 (CA8 2006)

(finding reasonable suspicion for a dog sniff based on 

implausible travel plans and nervous conduct); United 

States v. Ludwig, 641 F. 3d 1243, 1248–1250 (CA10 2011) 

(finding reasonable suspicion for a dog sniff where, among 

other things, the officer smelled “strong masking odors,” 

the defendant’s “account of his travel was suspect,” and 

the defendant “was exceptionally nervous throughout his 

encounter”).

Not only does the Court reach out to decide a question 

not really presented by the facts in this case, but the 

Court’s answer to that question is arbitrary. The Court 

refuses to address the real Fourth Amendment question: 

whether the stop was unreasonably prolonged. Instead, 

the Court latches onto the fact that Officer Struble delivered the warning prior to the dog sniff and proclaims that

the authority to detain based on a traffic stop ends when a

citation or warning is handed over to the driver. The 

Court thus holds that the Fourth Amendment was violated, not because of the length of the stop, but simply because of the sequence in which Officer Struble chose to 

perform his tasks.

This holding is not only arbitrary; it is perverse since 

Officer Struble chose that sequence for the purpose of 

protecting his own safety and possibly the safety of others. 

See App. 71–72. Without prolonging the stop, Officer

Struble could have conducted the dog sniff while one of the 

tasks that the Court regards as properly part of the traffic

stop was still in progress, but that sequence would have

entailed unnecessary risk. At approximately 12:19 a.m.,

after collecting Pollman’s driver’s license, Officer Struble 

did two things. He called in the information needed to do 

a records check on Pollman (a step that the Court recognizes was properly part of the traffic stop), and he requested that another officer report to the scene. Officer 

Struble had decided to perform a dog sniff but did not 
 

 

Cite as: 575 U. S. ____ (2015) 3 

ALITO, J., dissenting 

want to do that without another officer present. When 

occupants of a vehicle who know that their vehicle contains a large amount of illegal drugs see that a drugsniffing dog has alerted for the presence of drugs, they will 

almost certainly realize that the police will then proceed to

search the vehicle, discover the drugs, and make arrests.

Thus, it is reasonable for an officer to believe that an alert 

will increase the risk that the occupants of the vehicle will 

attempt to flee or perhaps even attack the officer. See, 

e.g., United States v. Dawdy, 46 F. 3d 1427, 1429 (CA8 

1995) (recounting scuffle between officer and defendant 

after drugs were discovered). 

In this case, Officer Struble was concerned that he was 

outnumbered at the scene, and he therefore called for 

backup and waited for the arrival of another officer before 

conducting the sniff. As a result, the sniff was not completed until seven or eight minutes after he delivered the

warning. But Officer Struble could have proceeded with

the dog sniff while he was waiting for the results of the

records check on Pollman and before the arrival of the 

second officer. The drug-sniffing dog was present in Officer Struble’s car. If he had chosen that riskier sequence 

of events, the dog sniff would have been completed before 

the point in time when, according to the Court’s analysis,

the authority to detain for the traffic stop ended. Thus, an 

action that would have been lawful had the officer made 

the unreasonable decision to risk his life became unlawful when the officer made the reasonable decision to wait 

a few minutes for backup. Officer Struble’s error— 

apparently—was following prudent procedures motivated 

by legitimate safety concerns. The Court’s holding therefore makes no practical sense. And nothing in the Fourth

Amendment, which speaks of reasonableness, compels this 

arbitrary line.

The rule that the Court adopts will do little good going 
 

4 RODRIGUEZ v. UNITED STATES 

ALITO, J., dissenting 

forward.2 It is unlikely to have any appreciable effect on

the length of future traffic stops. Most officers will learn 

the prescribed sequence of events even if they cannot

fathom the reason for that requirement. (I would love to 

be the proverbial fly on the wall when police instructors

teach this rule to officers who make traffic stops.)

For these reasons and those set out in JUSTICE 

THOMAS’s opinion, I respectfully dissent. 

—————— 

2 It is important to note that the Court’s decision does not affect procedures routinely carried out during traffic stops, including “checking 

the driver’s license, determining whether there are outstanding warrants against the driver, and inspecting the automobile’s registration 

and proof of insurance.” Ante, at 6. And the Court reaffirms that police 

“may conduct certain unrelated checks during an otherwise lawful 

traffic stop.” Ibid. Thus, it remains true that police may ask questions

aimed at uncovering other criminal conduct and may order occupants 

out of their car during a valid stop. See Arizona v. Johnson, 555 U. S. 

323, 333 (2009); Maryland v. Wilson, 519 U. S. 408, 414–415 (1997); 

Pennsylvania v. Mimms, 434 U. S. 106, 111 (1977) (per curiam).