PRECEDENTIAL

UNITED STATES COURT OF APPEALS

FOR THE THIRD CIRCUIT

______

No. 17-1576

______

UNITED STATES OF AMERICA

v.

WARREN CHARLES GREEN, IV,

 Appellant

______

On Appeal from the United States District Court 

for the Western District of Pennsylvania

(3-13-cr-00016-001)

District Judge: Honorable Kim R. Gibson

______

Argued October 23, 2017

Before: GREENAWAY JR., NYGAARD and FISHER, 

Circuit Judges.

(Filed: July 25, 2018)
2

Lisa B. Freeland, Esq.

Christopher B. Brown, Esq.

Kimberly R. Brunson, Esq. [ARGUED]

Office of Federal Public Defender

1001 Liberty Avenue

1500 Liberty Center

Pittsburgh, PA 15222

 Counsel for Appellant

Scott W. Brady, Esq.

Rebecca R. Haywood, Esq.

Michael L. Ivory, Esq. [ARGUED]

Office of United States Attorney

700 Grant Street, Suite 4000

Pittsburgh, PA 15219

 Counsel for Appellee

______

OPINION OF THE COURT

______

FISHER, Circuit Judge.

Following a traffic stop, police discovered 

approximately twenty pounds of heroin in the trunk of the car 

driven by Warren Charles Green, IV. Green appeals his 

resulting conviction, claiming that the traffic stop was both 

instigated and prolonged in violation of the Fourth 

Amendment. Finding no constitutional violation on either 

front, we will affirm the conviction.

I
3

A. Factual Background

This case involves three separate traffic stops, all 

performed by Pennsylvania State Trooper Michael Volk, that 

are arguably relevant to Green’s constitutional claims. As a 

drug interdiction officer, Volk’s duties largely consist of 

traveling on the Pennsylvania Turnpike in an unmarked 

cruiser to search for drugs, money, and weapons. Each of the 

stops occurred on the Turnpike in the vicinity of Somerset, 

roughly 70 miles east of Pittsburgh. The first stop involved 

two men with no further direct connection to the case. The 

latter two stops both involved Green. The Government argues 

that information Volk obtained during the first stop helped 

contribute to reasonable suspicion of Green’s criminal 

activity during the final stop, which led to the heroin 

discovery. 

April 3, 2013

Volk stopped a vehicle traveling eastbound on the 

Pennsylvania Turnpike. This stop did not involve Green, but 

rather two other men who, like Green, are black. The men had 

a dog in their back seat. Volk’s stated reason for the stop was 

for following too closely, but he suspected that the stopped 

vehicle and another vehicle traveling close by were involved 

in drug trafficking. The occupants stated that they were 

traveling to Long Branch, New Jersey, in order to breed the 

dog, which they described as an “American Bully.” Volk’s 

computer was not working at the time, so he let the 

individuals go with a verbal warning. Later that day, Volk 

learned that at least one of the occupants was on federal 

pretrial release for drug violations.

April 4, 2013

At approximately 8 a.m. the next day, Volk 

simultaneously pulled over two separate vehicles traveling 

eastbound on the Turnpike. Again, Volk believed that the two 
4

cars were travelling together and involved in drug trafficking. 

The stated reasons for the stops were a license plate violation 

and illegal window tinting. Both drivers denied knowing each 

other. The first driver, a white male, informed Volk that he 

was traveling to Baltimore for work. Green drove the second 

vehicle and informed Volk that he was going to Philadelphia 

to see family. When Volk asked Green how long he was 

planning to stay in Philadelphia, Green initially responded, “I 

don’t know. That all depends,” at which point Volk began to 

speak over him, laughing, and asked, “You don’t have to get 

back for work or anything?” Green explained that he owned a 

barbershop, so he had a good amount of flexibility with 

regard to the hours he worked. Nothing else was discussed 

about the planned duration of Green’s trip and the 

conversation diverted to other topics. A check of Green’s 

license revealed that he had multiple prior arrests for drug and 

weapon offenses, though Volk was unaware if Green had any 

prior convictions. 

After several minutes, Volk brought Green to the rear 

of Green’s vehicle and issued a warning for the window tint 

violation. Green told Volk that he had only recently 

purchased the vehicle and that the windows had been tinted 

by the previous owner. Volk then told Green he could 

continue on his way. As Green was walking back to the 

driver’s side of his car, Volk asked him if there was anything 

in the vehicle that should not be there. Green responded that 

there was not. Volk then asked for Green’s consent to search 

the vehicle and Green acceded, eventually signing a waiver. 

Volk searched Green’s vehicle, including the engine 

compartment, for roughly twelve minutes and did not 

discover any contraband. In fact, Green did not have any 

luggage or baggage of any kind in his vehicle. While 

conducting the search, Volk detected the smell of raw 
5

marijuana in the trunk compartment and noticed that the trunk 

liner was pulled back. Volk did not discuss any of these 

observations with Green. Following the search, Volk allowed 

Green to continue on his way. Volk also received consent to 

search the other vehicle and similarly uncovered no 

contraband.

April 5, 2013

At approximately 10 a.m. the following day, Volk was 

removing debris on the side of the Turnpike and noticed 

Green’s vehicle traveling westbound. By his own admission, 

Volk decided at this point that he would try to find a reason to 

stop Green. Volk followed Green and ascertained his speed 

by “pacing” Green’s vehicle. When pacing, an officer finds 

the speed at which his vehicle remains equidistant from the 

target vehicle in order to assess the target vehicle’s speed. See

75 Pa. Cons. Stat. § 3368 (requirements for pacing). Here, 

Volk followed one to two-tenths of a mile behind Green’s car 

for a distance of roughly six-tenths of a mile. The speed limit 

on that portion of the Turnpike was 65 miles per hour. Volk 

determined that Green was traveling 79 miles per hour and 

pulled him over. After walking up to Green’s window, Volk 

feigned surprise, saying, “You again!” in a light-hearted 

manner. When Volk noted that he pulled Green over for 

speeding, Green apologized and said that he had left the 

cruise control on while going down a hill. As Green was 

gathering his license and registration, he asked Volk, “How 

you doin’ today?” Volk replied and then asked Green how he 

was doing, to which Green responded, “I can’t complain. I 

got a dog, so.” Volk then observed a dog in the back of 

Green’s vehicle and believed it was—or at least resembled—

the dog from the April 3 stop. Volk asked Green why he had 

returned from Philadelphia after only one day, despite saying 

the day before that he would be there for “a couple days.” As 
6

quoted above, Green did not actually say he would be gone “a 

couple days” during the earlier stop, but that was how Volk 

remembered the previous day’s conversation. In any event, 

Green explained that he was returning from Philadelphia 

because his daughter had just broken her leg, so he had to 

hurry back to take care of her. This conversation lasted about 

forty seconds.

After returning to his cruiser with Green’s license and 

registration, Volk immediately called a colleague to fill him 

in on the events dating back to April 3. This phone call lasted 

roughly two minutes and had a decidedly jocular tone. Volk 

had already requested backup prior to his initial conversation 

with Green and waited in his vehicle for its arrival. It is 

unclear whether Volk also requested a canine unit at this time. 

About eight minutes after the end of his phone call, and with 

backup not having arrived, Volk called Green to the rear of 

Green’s vehicle.1 Volk again issued Green a warning and 

Green struck up a lengthy conversation about his daughter’s 

injury. During this exchange, both Volk and Green stood at 

the rear of Green’s vehicle observing the dog through the 

back window. Green described the dog’s breed as a “Cane 

Corso” or “Presa Canario,” and related that he had bought the 

dog from a kennel somewhere outside of Philadelphia, though 

he could not recall the name of the exact town. As had

happened the day before, Volk indicated that Green was free 

to leave, but as Green was walking back to the driver’s door, 

Volk again asked if he could search Green’s vehicle. This 

time, Green apologized and declined, explaining that he was 

in too much of a hurry. Volk then instructed Green to wait in 

his car until further notice.

 

1 The record does not reveal why Volk chose not to 

wait any longer for backup.
7

After approximately fifteen minutes, during which 

there was no meaningful interaction between Volk and Green, 

a canine unit arrived. Green was taken out of his vehicle and 

told to take his dog with him to a safe distance away from the

police dog.

2 A canine sweep of the car resulted in an alert for 

drugs in the trunk. Based on this evidence, Volk obtained a 

search warrant a few hours later. A search of Green’s trunk 

revealed a duffel bag containing roughly 1,000 bricks of 

heroin weighing nearly 20 pounds.

B. Procedural History

Green was charged with possession with intent to 

distribute one kilogram or more of heroin. Green filed a 

motion to suppress the heroin as obtained in violation of the 

Fourth Amendment. The District Court held an evidentiary 

hearing nearly three years after the original stop, in which 

Volk testified as the only witness. After the District Court 

denied Green’s motion, he pled guilty to the single count, 

preserving the constitutional issues for appeal. Green was 

sentenced to 120 months of imprisonment—the mandatory 

minimum—followed by five years of supervised release. 

II

The District Court exercised jurisdiction under 28 

U.S.C. § 3231, and this Court exercises jurisdiction under 28 

U.S.C. § 1291. On an appeal of a denial of a motion to 

suppress, the District Court’s factual findings are reviewed 

for clear error and its legal determinations are subject to 

 

2 At this point, Volk performed a patdown of Green. 

Green’s claim that this patdown was unconstitutional is 

without merit. See United States v. Murray, 821 F.3d 386, 

393 (3d Cir. 2016) (holding that a suspect’s connection with 

drug dealing supports reasonable suspicion that he is armed 

and dangerous).
8

plenary review. United States v. Lewis, 672 F.3d 232, 237 (3d 

Cir. 2012). We will affirm the District Court’s denial of 

Green’s motion to suppress. Although our reasoning differs in 

some respects from that of the District Court, we may affirm 

on any ground supported by the record. Tourscher v. 

McCullough, 184 F.3d 236, 240 (3d Cir. 1999).

III

Green’s constitutional claims require us to answer 

several discrete questions. First, we must assess whether the 

District Court erred when it ruled that the final traffic stop on 

April 5 was supported by reasonable suspicion of a traffic 

violation. If there was no error, we must proceed to determine 

whether the District Court was also correct in its 

determination that the stop was conducted in a constitutional 

manner. Green argues that the stop was prolonged in violation 

of the Fourth Amendment. To address this claim, we must 

first decide when the stop was extended, and then determine 

whether, at that point, the extension was justified by a 

reasonable suspicion of criminal activity.

A. Initiation of the Traffic Stop

We turn first to Green’s contention that the April 5 

stop was initiated in violation of the Fourth Amendment. 

Traffic stops are classified as a type of Terry stop, and may be 

initiated based on a reasonable suspicion that a traffic 

violation has occurred. Navarette v. California, 134 S. Ct. 

1683, 1686 (2014); see United States v. Delfin-Colina, 464 

F.3d 392, 396–97 (3d Cir. 2006) (adopting reasonable 

suspicion, not probable cause, as the applicable standard). 

Here, Volk paced Green’s vehicle in compliance with the 

relevant Pennsylvania statute and estimated his speed at 79 

miles per hour, 14 miles per hour above the posted limit. 

Conceding these facts, Green nonetheless argues that the 

distance at which Volk conducted the pacing—between one 
9

and two-tenths of a mile—was too great to allow for a reliable 

estimate of Green’s speed. We disagree. 

When pacing, the key requirement is maintaining a 

consistent distance with the target vehicle. At the suppression 

hearing, Volk testified that he was able to maintain a constant 

interval between himself and Green. The District Court found 

that Green’s vehicle was some distance from Volk’s, but not 

so far that Volk would have been unable to determine if the 

interval between the two was increasing, decreasing, or 

remaining constant. The dashboard camera footage from 

Volk’s cruiser shows that this factual finding is not clearly

erroneous. Our confidence in Volk’s assessment is further 

supported by the fact that Green was traveling significantly 

faster than the speed limit allowed. Logically, the more 

excessive a driver’s speed, the less precise a measurement 

must be to establish reasonable suspicion that the driver is 

speeding at least to some degree. See United States v. 

Sowards, 690 F.3d 583, 591–92 (4th Cir. 2012). The 

operative question is whether Volk had a reasonable 

suspicion that Green was speeding, not whether Volk could

determine Green’s exact speed. The District Court did not err 

in concluding that Volk had a reasonable suspicion that Green 

was speeding, so the stop was justified.

3

B. Extension of the Traffic Stop

We next consider whether the April 5 traffic stop, 

though “lawful at its inception,” was unreasonably extended 

 

3 Green’s argument that the stop was pretextual is both 

true and immaterial. It has long been axiomatic that “a trafficviolation arrest . . . [is not] rendered invalid by the fact that it 

was ‘a mere pretext for a narcotics search.’” Whren v. United 

States, 517 U.S. 806, 812–13 (1996) (quoting United States v. 

Robinson, 414 U.S. 218, 221 n.1 (1973)).
10

in violation of the Fourth Amendment. Illinois v. Caballes, 

543 U.S. 405, 407 (2005). An unreasonable extension occurs 

when an officer, without reasonable suspicion, diverts from a 

stop’s traffic-based purpose to investigate other crimes. 

Rodriguez v. United States, 135 S. Ct. 1609, 1615 (2015). 

There is no dispute that the April 5 traffic stop was extended 

to facilitate a canine sniff for drugs. What is disputed, 

however, is when this extension occurred, and whether, at 

that moment, Volk possessed reasonable suspicion in order to 

justify the extension. In light of Rodriguez, we must first 

determine when the stop was “measurably extend[ed].” Id.

(quoting Arizona v. Johnson, 555 U.S. 323, 333 (2009)).

After determining when the stop was extended—the 

“Rodriguez moment,” so to speak—we can assess whether the 

facts available to Volk at that time were sufficient to establish 

reasonable suspicion that Green was involved in drug 

trafficking. 

As subsequent cases in our sister Circuits have 

demonstrated, the Rodriguez rule is far easier to articulate 

than to apply, and we now find ourselves facing a similar 

difficulty. We ultimately conclude that Rodriguez does not 

provide a clear answer for pinpointing the April 5 “Rodriguez

moment.” In light of such uncertainty—and solicitous of 

Green’s Fourth Amendment rights—we will err on the side of 

caution and assume the earlier of the two plausible 

“Rodriguez moments” from which to assess reasonable 

suspicion. Because Volk did indeed possess reasonable 

suspicion at this earlier point, Green suffered no 

constitutional injury in the course of the traffic stop.

The Rodriguez Decision

Prior to Rodriguez, the Supreme Court held in 

Caballes that a “dog sniff conducted during a . . . lawful 

traffic stop” does not violate the Fourth Amendment as long 
11

as the sniff does not result in the stop being “prolonged 

beyond the time reasonably required to complete” its trafficbased mission. 543 U.S. at 410, 407. Following Caballes, 

lower courts disagreed over whether a de minimis extension 

of a traffic stop to allow time for a sniff would pass 

constitutional muster. Rodriguez, 135 S. Ct. at 1614 

(comparing cases). Rodriguez answered this question with a 

clear “no,” holding that, absent reasonable suspicion, any 

“unrelated inquiries [that] measurably extend the duration of 

[a] stop” are unlawful. Id. at 1615 (alterations added and 

omitted) (quoting Johnson, 555 U.S. at 333). In describing 

what inquiries qualify as “unrelated,” Rodriguez drew a 

distinction between “ordinary inquiries incident to” a traffic 

stop, id. (quoting Caballes, 543 U.S. at 408), which serve the 

purpose of enforcing the traffic code, and other measures 

aimed at detecting criminal activity more generally. Actions 

like “checking the driver’s license, determining whether there 

are outstanding warrants against the driver, and inspecting the 

automobile’s registration and proof of insurance” are in the 

former category of inquiries incident to a traffic stop. Id. A 

dog sniff, being obviously focused on the enforcement of 

drug—not traffic—laws, falls in the latter category and

cannot, therefore, be performed in a manner that extends the 

duration of the stop absent reasonable suspicion. Id.

The task of determining when a traffic stop is 

“measurably extended” is more difficult than Rodriguez’s

language might suggest. This difficulty stems, at least in part, 

from the particular facts of both Caballes and Rodriguez. In 

Caballes, the trooper making the stop radioed dispatch to 

report his actions. This transmission happened to be 

overheard by a drug interdiction officer, who immediately 

traveled to the scene and conducted the dog sniff before any 

citation had been issued. Caballes, 543 U.S. at 406. In 
12

Rodriguez, by contrast, the officer who initiated the stop 

already had a drug dog in his vehicle. 135 S. Ct. at 1612. For 

safety reasons, however, he issued a warning for speeding and 

then waited for backup to arrive before conducting the dog 

sniff. Id. at 1613. The Court declared the former stop

constitutional and the latter not. Neither case directly 

addressed what pre-citation conduct might constitute an 

impermissible extension. 

Justice Alito, dissenting in Rodriguez, criticized the 

Court’s decision as “impractical[] and arbitrary,” and 

lamented that the constitutional question appeared to turn, 

“not [on] the length of the stop, but simply . . . the sequence 

in which [the officer] chose to perform his tasks.” 135 S. Ct. 

at 1623, 1624 (Alito, J., dissenting). The majority disclaimed 

this reading of its opinion, stating that “[t]he critical question 

. . . is not whether the dog sniff occurs before or after the 

officer issues a ticket . . . but whether conducting the sniff 

‘prolongs’—i.e., adds time to—‘the stop’” Id. at 1616

(majority opinion). On this “critical question,” however, 

Rodriguez’s language can be interpreted in a variety of ways. 

Id. In describing an extension as anything that “adds time to,” 

id., or “measurably extend[s],” id. at 1615, a stop, the Court 

seems to imply that nearly anything an officer does outside 

the valid, traffic-based inquiries will be unconstitutional. Yet, 

other language in the opinion suggests a more forgiving 

approach toward non-traffic-based actions. This ambiguity is 

brought to the fore with a pair of adjoining sentences: “An 

officer . . . may conduct certain unrelated checks during an 

otherwise lawful traffic stop. But . . . he may not do so in a 

way that prolongs the stop . . . .” Id. (citation omitted). Left 

unexplained is how a police officer could possibly perform 

multiple tasks simultaneously without adding any time to a 

stop. While the majority makes clear that, contra Justice 
13

Alito, sequence is not dispositive, id. at 1616, Rodriguez

provides less clarity regarding what exactly is dispositive 

when evaluating an officer’s pre-citation conduct. 

In a more general sense, Justice Alito’s concern was 

that the Court’s attempt to craft a clear rule—no measurable 

extensions—was impractical in light of the factual complexity 

inherent in traffic stops. Id. at 1625 (Alito, J., dissenting). For 

this reason, Justice Alito favored a more flexible 

reasonableness standard to better account for the practical 

realities of traffic stops, and warned that the Court’s ruling 

would invite arbitrary and unpredictable results. Id. at 1624. 

A survey of post-Rodriguez appellate decisions reveals that 

Justice Alito’s concerns were prophetic. The Rodriguez rule, 

though clear in its formulation, has proved less precise where 

the rubber meets the road.

Post-Rodriguez Decisions

In several recent decisions, our sister Circuits have 

adopted starkly divergent interpretations of Rodriguez. 

Several have applied Rodriguez’s language quite rigidly, 

holding that any diversion from a stop’s traffic-based mission 

is unlawful absent reasonable suspicion. In United States v. 

Gomez, for example, an officer stopped a vehicle for speeding 

and running red lights. 877 F.3d 76, 82 (2d Cir. 2017). When 

the officer first approached the vehicle, the driver asked the 

officer why he had been stopped, and the officer responded 

that he was conducting a heroin investigation and that he had 

observed the driver commit numerous traffic violations. Id.

The Second Circuit determined that, by referencing the drug 

investigation, the officer unconstitutionally detoured from the 

traffic-based mission of the stop “[f]rom the moment” the 

conversation began. Id. at 91. In United States v. Evans, an 

officer initiated a traffic stop and conducted a vehicle records 

check, a license check, and an outstanding warrants check, all 
14

of which came back clean. 786 F.3d 779, 782–83 (9th Cir. 

2015). One of these checks, however, revealed that the 

stopped driver had a felony record. Id. at 783. Accordingly, 

the officer requested a check to verify that the driver was 

properly registered at the address that he had provided. Id.

The Ninth Circuit ruled that, while the first two checks were 

permissible, the ex-felon registration check, not being directly 

relevant to the traffic stop, unconstitutionally extended the 

stop under Rodriguez. Id. at 786.

Other Circuits have applied Rodriguez more leniently, 

evaluating police actions by something more akin to a 

reasonableness standard. In United States v. Collazo, the 

Sixth Circuit found no constitutional violation because “most 

of the questions” asked by the officer were related to the 

traffic stop, “and none of them extended the traffic stop 

beyond a reasonable time.” 818 F.3d 247, 257–58 (6th Cir. 

2016) (citing Rodriguez, 135 S. Ct. at 1615), cert. denied, 137 

S. Ct. 169 (2016). More categorically, the Seventh Circuit 

held in United States v. Walton that “[i]t was permissible for 

[the sole officer on-scene] to ask [the driver and passenger] 

questions unrelated to the traffic violations,” 827 F.3d 682, 
15

687 (7th Cir. 2016), cert. denied, 137 S. Ct. 407 (2016),

which undoubtedly extended the stop.4

As these examples demonstrate, Caballes and 

Rodriguez are difficult to apply beyond their facts, which has 

resulted in inconsistent application in the lower courts. 

Where, as in the present case, an officer arguably prolongs a 

traffic stop before issuing a citation, these precedents serve as 

an uncertain guide. What we know is that an officer may 

“conduct certain unrelated checks,” but not “in a way that 

prolongs the stop.” Rodriguez, 135 S. Ct. at 1615.

Applying Rodriguez

This case presents many of the same ambiguities 

highlighted above. There can be no doubt that Volk 

measurably extended the traffic stop when, after issuing 

Green a warning citation, he instructed Green to wait in his 

car indefinitely. The key question is whether the stop was 

measurably extended at an earlier point—that is, whether the 

“Rodriguez moment” instead occurred when Volk returned to 

his vehicle after his brief initial conversation with Green and 

made an unrelated phone call to his colleague. If it did, then 

nothing later in the stop can inform our reasonable suspicion 

 

4 Even in traffic stop cases where courts have found no 

Fourth Amendment violations, several dissenting opinions 

have voiced the more restrictive interpretation of Rodriguez. 

See United States v. Murillo-Salgado, 854 F.3d 407, 419 (8th 

Cir. 2017) (Kelly, J., dissenting) (arguing that “even brief[]” 

questioning unrelated to the traffic stop must be supported by 

reasonable suspicion); United States v. Hill, 852 F.3d 377, 

385 (4th Cir. 2017) (Davis, J., dissenting) (arguing that 

“every minute” an officer spent seeking to confirm a 

passenger’s identity unreasonably prolonged the traffic stop).
16

analysis. This includes, most significantly, the conversation 

that occurred when Volk issued the citation to Green.

Under a restrictive reading of Rodriguez, it seems clear 

that Volk’s actions following the initial conversation with 

Green, particularly the phone call to his colleague, added time

to the traffic stop and constituted an extension. See Gomez, 

877 F.3d at 90–91. This phone call was focused on Volk’s 

suspicions about drug trafficking, not speeding. At the 

suppression hearing, Volk conceded that, by the time he made 

this call, he was intent on searching Green’s vehicle and no 

longer concerned with the moving violation.5

On the other hand, there are sound reasons in favor of 

the more lenient approach followed by several Circuits. To 

start, this short phone call, though unrelated to the traffic stop, 

was not shown to have measurably prolonged the stop, which 

took little more than ten minutes from its inception to the 

issuance of the warning. Other courts have found that phone 

calls requesting canine assistance are not measurable 

extensions, United States v. Hill, 852 F.3d 377, 384 (4th Cir. 

2017), though this conclusion is far from obvious under the 

reasoning of Rodriguez. Additionally, at the time Volk made 

the phone call he was apparently still waiting for backup, 

 

5 When asked about this portion of the stop, Volk 

testified as follows:

Q. At this point you are focused on “I am searching this car, 

right?”

A. I would like to, yes.

Q. This is not a moment about giving a warning for a 

speeding ticket, right?

A. Correct.

App. 193.
17

which raises its own set of considerations. Rodriguez 

acknowledged the danger to police officers inherent in traffic 

stops, and found no constitutional injury where an officer 

takes “negligibly burdensome precautions in order to 

complete his [traffic] mission safely.” 135 S. Ct. at 1616. By 

contrast, “safety precautions taken in order to facilitate” 

investigation of other crimes are not justified as part of a 

routine traffic stop. Id. Assuming Volk’s request for backup 

was motivated by safety concerns inherent to the traffic stop, 

then any actions taken while waiting for backup to arrive, 

including the phone call, did not add to the “time reasonably 

required to complete the mission.” Id. at 1615 (alteration 

omitted) (quoting Caballes, 543 U.S. at 407). Rodriguez

would seem to suggest that the validity of Volk waiting for 

backup turns on his motivation for making the request—

traffic-based or otherwise—but even this inquiry strikes us as 

rather arbitrary. We doubt very much that Volk’s motivation 

can be distilled to a single concern rather than a hazy 

constellation of factors confronting an officer in such a 

situation. Of course, Volk ultimately chose not to wait for 

backup to arrive before reengaging with Green, which adds 

still greater complexity to the analysis. 

In light of the uncertainty in applying Rodriguez to the 

present facts, we believe that the prudent course is to err on 

the side of caution and proceed on the assumption—not 

conclusion—that the “Rodriguez moment” occurred 

immediately after Volk’s initial conversation with Green. 

Accordingly, we will assess reasonable suspicion based only 

on the facts known to Volk at that time. Because we conclude 

that Volk did possess reasonable suspicion at this moment, 

there will be no need to address the possible implications of a 

later “Rodriguez moment.” 
18

C. Reasonable Suspicion

We now ask whether, at our assumed “Rodriguez

moment,” Volk possessed reasonable suspicion of criminal 

activity. In speaking of reasonable suspicion, our precedents 

describe more than define the term, which the Supreme Court 

has characterized as an “elusive concept.” United States v. 

Cortez, 449 U.S. 411, 417 (1981). Reasonable suspicion is 

more than “a mere hunch . . . [but] considerably less than . . . 

a preponderance of the evidence, and obviously less than . . . 

probable cause.” Navarette, 134 S. Ct. at 1687 (internal 

quotation marks and citations omitted) (quoting Cortez, 449 

U.S. at 417; and Terry v. Ohio, 392 U.S. 1, 27 (1968)). 

Reasonable suspicion requires only “‘a particularized and 

objective basis’ for suspecting . . . criminal activity,” Ornelas 

v. United States, 517 U.S. 690, 696 (1996) (quoting Cortez, 

449 U.S. at 417–418), and should not be derived from 

characteristics common to the “vast majority of innocent” 

individuals, Karnes v. Skrutski, 62 F.3d 485, 494 (3d Cir. 

1995).

In applying this standard, courts invoke several 

common themes. First, reasonable suspicion must always be 

evaluated under the totality of the circumstances. Cortez, 449 

U.S. at 417. Accordingly, courts have consistently refused to 

adopt per se rules declaring a particular factor sufficient or 

insufficient to establish reasonable suspicion. See Illinois v. 

Wardlow, 528 U.S. 119, 126–27 (Stevens, J., dissenting) 

(agreeing with the Court’s rejection of a per se rule regarding 

flight from police). Second, when assessing the totality of the 

circumstances, courts recognize the particular ability of law 

enforcement officers, based on training and experience, “to 

make inferences from and deductions about the cumulative 

information available to them that ‘might well elude an 

untrained person.’” United States v. Arvizu, 534 U.S. 266, 273 
19

(2002) (quoting Cortez, 449 U.S. at 418). Third, and 

consistent with the totality of the circumstances approach, 

reasonable suspicion cannot be defeated by a so-called 

“divide-and-conquer” analysis, whereby each arguably 

suspicious factor is viewed in isolation and plausible, 

innocent explanations are offered for each. District of 

Columbia v. Wesby, 138 S. Ct. 577, 589 (2018). In Terry

itself, the Court found there was reasonable suspicion to 

justify the temporary seizures even though each factor relied 

on by the officer, viewed in isolation, might have seemed 

perfectly innocent. Arvizu, 534 U.S. at 274 (citing Terry, 392

U.S. at 22). 

The Prior Stop and Search

 Applying this standard to the present case, our first 

challenge is determining the constitutional significance of the 

first encounter between Green and Volk on April 4. During 

that stop, Green consented to a search of his vehicle, which 

failed to uncover any contraband. The Government argues 

that the unsuccessful nature of the April 4 search is 

essentially irrelevant to the question of reasonable suspicion 

on April 5. Green counters that, because he consented to the 

April 4 search and was found free of contraband, no 

information from the search could be used to support 

reasonable suspicion on April 5. Essentially, Green argues 

that the April 4 search gave him a clean slate moving 

forward. In support, Green cites United States v. Peters, 10 

F.3d 1517 (10th Cir. 1993), which likewise included multiple 

traffic stops in relatively quick succession. The District Court, 

perhaps seeking to avoid this thorny issue, purported to 

conduct an independent analysis of the April 5 facts alone. In 

reality, however, the District Court’s analysis incorporated 

several facts from the preceding two days. For instance, the 

District Court found Green’s travel on April 5 to be 
20

suspicious, but could have only reached this conclusion by 

relying on Green’s April 4 statements about his travel plans.

The present case is easily distinguishable from Peters. 

There, an officer pulled over the defendant and his passenger 

for erratic driving in a rented moving truck. The officer 

suspected that Peters was transporting drugs, and received 

consent to search his truck. This search failed to uncover any 

contraband and the officer sent Peters on his way. Concerned 

that his search had been inadequate, the officer radioed his 

headquarters about the situation. This led to Peters again 

being pulled over a few hours down the road, at which point a 

different officer uncovered evidence that Peters was present 

in the country illegally. The Tenth Circuit ruled that this 

evidence should have been suppressed because the second 

stop was unconstitutionally premised on the same factors that 

justified the initial stop. Id. at 1522–23. 

In Green’s case, roughly twenty-six hours elapsed 

between the two traffic stops, as opposed to the four or five 

hour interval in Peters. In addition, the nature of Green’s 

suspected crime—drug trafficking—made it entirely plausible 

for Green to have acquired drugs during the intervening time 

period. In Peters, by contrast, the officers all but knew that 

the suspect had driven uninterrupted between the two traffic 

stops. Id. at 1520. In fact, they relied on this assumption to 

predict Peters’ location for the second stop. Id. Those officers 

could not have reasonably suspected that Peters acquired 

contraband between the two stops. Nor was that the point; the 

second search was simply a redo of the first. Finally, in Peters

there was no independent basis for making the second traffic 

stop. Id. at 1523. Here, Green’s speeding provided a 

legitimate justification for the April 5 stop. 

Given these substantial differences, we see no 

reason—constitutional or otherwise—to follow Peters and 
21

exclude from our analysis information gained during the 

April 4 stop. It bears repeating: reasonable suspicion is based 

on the totality of the circumstances, i.e., “the whole picture.” 

Cortez, 449 U.S. at 417. Categorically excluding a large 

swath of evidence is quite the opposite of considering “the 

whole picture.” Incidentally, this case illustrates that the 

totality of the circumstances approach does not inherently 

benefit either side. For instance, although our analysis 

appropriately considers the fact that Volk detected the smell 

of raw marijuana emanating from Green’s trunk on April 4, 

we also consider as strong evidence the fact that Green’s 

vehicle was searched and contained no contraband. “[T]he 

ultimate touchstone of the Fourth Amendment is 

‘reasonableness’ . . . .” Brigham City, Utah v. Stuart, 547 

U.S. 398, 403 (2006) (quoting Flippo v. West Virginia, 528 

U.S. 11, 13 (1999) (per curiam)). In our view, a reasonable 

officer in Volk’s position, rather than excluding certain 

evidence, would consider all of the facts available to him and 

accord each its due weight. In evaluating his actions, the 

Constitution requires that we do likewise.

Reasonable Suspicion Factors

As noted above, when evaluating reasonable suspicion 

a court’s task is to assess the situation as a whole. 

Nevertheless, in explaining our analysis it will often be 

beneficial, for the sake of clarity, to explain each factor’s 

relative weight in establishing reasonable suspicion. In 

accordance with our Rodriguez analysis, we will only 

consider those facts known to Volk at the time he completed 

his conversation with Green at the beginning of the April 5 

stop. We conclude that Volk possessed a reasonable suspicion 

that Green was engaged in criminal activity. This conclusion 

is based on three primary factors: (1) Green’s misleading 
22

statements regarding his travel, (2) the smell of marijuana in 

Green’s trunk, and (3) Green’s criminal history.6

1. Green’s Misleading Statements

Shortly after being stopped on April 4, Green related 

to Volk that he was traveling to Philadelphia to visit family. 

Volk asked Green how long he was staying, to which Green 

responded, “I don’t know. That all depends.” Volk 

immediately began to laugh and, speaking over Green, asked 

“You don’t have to get back for work or anything?” Green 

responded that he was a barber, so his hours were fairly

flexible. Roughly twenty-six hours later, Volk pulled Green 

over again as he returned from Philadelphia to Pittsburgh. 

Based on these facts, the District Court concluded that 

Green’s statements “about his travels to Philadelphia were 

inconsistent and contradictory,” and thus contributed to 

Volk’s reasonable suspicion.

As an initial matter, we note that nothing in Green’s 

statement to Volk on April 4 was logically inconsistent with 

his April 5 return. Green’s statement indicated that his trip 

was for an indeterminate length of time, which obviously 

does not foreclose a one-day turnaround. Contradictory or 

inconsistent statements may contribute to reasonable 

suspicion, United States v. Givan, 320 F.3d 452, 459 (3d Cir. 

2003), but an incomplete statement is not necessarily 

contradictory or inconsistent. For all we know, Green’s 

complete, uninterrupted statement would have been, “I don’t 

know. That all depends. Probably tomorrow, but maybe the 

next day.” The fact that Green did not provide a full statement 

 

6 Because these factors were sufficient to establish 

reasonable suspicion, we will not analyze what, if any, 

inferences could be drawn from the dog in Green’s car.
23

about his travel plans limits, but does not defeat, our reliance 

on this factor.

Though not strictly contradictory, Green’s statements 

concerning his travel were sufficiently confusing so as to 

meaningfully contribute to reasonable suspicion. While not 

logically irreconcilable with his earlier statement, Green’s 

travel was nonetheless suspicious. See United States v. 

Benoit, 730 F.3d 280, 285–86 (3d Cir. 2013) (premising 

reasonable suspicion on inconsistent statements regarding the

purpose and destination of voyage). In the context of a crossstate trip to visit family for the first time in a while, the 

answer “I don’t know. That all depends,” is not how someone 

would normally characterize the duration of a trip that could 

possibly last only a few hours. More to the point, we cannot

say that Volk was unreasonable in believing that Green’s 

April 4 statement was at least in tension with an April 5 

return.

In our mind, however, the more significant suspicion 

arose, not from Green’s quick turnaround, but his own 

statements on April 5. While Green was looking for his 

license and registration at the beginning of the April 5 stop, 

Volk asked him how he was doing and Green replied, “I can’t 

complain. I got a dog, so.” Only after Volk alluded to their 

conversation the day before—“I thought you were staying out 

a couple days?”—did Green say he needed to rush back to 

Pittsburgh because of his daughter’s broken leg.7 Volk was 

justified in viewing Green’s shifting statements with 

mounting skepticism. If it was true that Green’s family visit 

 

7 The fact that Green did not challenge Volk’s 

presumption regarding the intended duration of his trip 

further mitigates our concern over Volk interrupting Green on 

April 4.
24

had been cut short due to his daughter suffering a serious 

injury, it is hard to imagine him responding to Volk’s 

question—“How are you?”—with such a blasé answer—“I 

can’t complain. I got a dog, so.” Moreover, Green had already 

been informed that he was stopped for speeding, so it is 

highly suspicious that he would not immediately offer his 

daughter’s purported injury as an explanation for his rushing 

home. Instead, Green’s initial explanation for speeding was 

simply that he had left his cruise control on while going down 

a hill. Green’s puzzling responses provided a reasonable basis 

to believe that he was lying about his travels and contributed 

to Volk’s reasonable suspicion of illegal activity. 

2. The Smell of Marijuana

During the consensual search of Green’s car on April 

4, Volk detected the smell of raw marijuana in the trunk. Volk 

was unable to locate the source of the smell, and the car was 

otherwise free of contraband. “It is well settled that the smell 

of marijuana alone . . . may establish not merely reasonable 

suspicion, but probable cause.” United States v. Ramos, 443 

F.3d 304, 308 (3d Cir. 2006). Green, however, argues that the 

unsuccessful search on April 4 eliminated any probative value 

of the odor. We disagree. While the fact that no marijuana 

was found on April 4 is certainly a relevant consideration, it 

does not preclude our—or Volk’s—consideration of this 

evidence in support of reasonable suspicion on April 5. 

The odor of marijuana in a car “can ‘be evidence of the 

most persuasive character,’” Wesby, 138 S. Ct. at 586 n.5 

(quoting Johnson v. United States, 333 U.S. 10, 13 (1948)), 

and is not an attribute shared by “a very large category of 

presumably innocent travelers,” Reid v. Georgia, 448 U.S. 

438, 441 (1980) (per curiam). The absence of actual

marijuana on April 4 mitigates, but does not eliminate, the 
25

probative value of this evidence.8 We agree with the 

reasoning in Peters that, having conducted a prior search, the 

officer could not justify a subsequent search absent additional 

evidence. 10 F.3d at 1522–23. But here, the April 5 stop was 

independently justified and there was additional evidence to 

support reasonable suspicion. In this context, we find no basis 

in law or logic to prohibit consideration of the marijuana odor 

merely because Green was not transporting drugs the day 

before. Reasonable suspicion must be grounded in “the 

factual and practical considerations of everyday life on which 

reasonable and prudent men, not legal technicians, act.” 

Brinegar v. United States, 338 U.S. 160, 175 (1949). The 

smell of marijuana is one such “practical consideration” 

familiar to an officer with Volk’s experience in the field. The 

Fourth Amendment does not demand the kind of cognitive 

contortions that would be required for Volk to ignore highly 

probative evidence of drug activity in deciding whether he 

had reasonable suspicion to extend the stop. Volk was 

 

8 Our analysis would be different if, for example, Volk 

had seen something he believed to be marijuana but turned 

out to be some other leafy substance. See Karnes, 62 F.3d at 

496. In that situation, later investigation would have 

“exhausted” the validity of the earlier suspicion. Peters, 10 

F.3d at 1522. Here, the smell of marijuana suggested that 

Green had recently transported drugs. The absence of drugs at 

any particular moment in no way foreclosed this inference. 
26

justified in relying on this odor as evidence of criminal 

activity on April 5.9

3. Green’s Criminal History

During the April 4 stop, Volk conducted a records 

check and discovered that Green had multiple prior arrests for 

drug and firearm violations. Volk did not learn how those 

arrests were ultimately resolved or whether Green had any 

convictions. Though a criminal record, much less an arrest 

record, is not sufficient to establish reasonable suspicion, it is 

a valid factor. United States v. Mathurin, 561 F.3d 170, 177 

(3d Cir. 2009). As we have previously noted, “the use of prior 

arrests and convictions to aid in establishing probable cause is 

not only permissible, but is often helpful.” United States v. 

Conley, 4 F.3d 1200, 1207 (3d Cir. 1993) (citations omitted) 

(collecting cases). This utility is enhanced when the prior 

offenses relate to the crime being investigated. Id. Particularly 

given the other factors already discussed, Volk was amply 

justified in considering Green’s drug arrests in assessing 

reasonable suspicion of drug trafficking on April 5.

IV

 

9 Following oral argument, Green brought to our 

attention a study raising questions about the reliability of 

individuals’ ability to detect marijuana based on odor. 

Appellant Letter of Oct. 30, 2017 (citing Richard L. Doty, 

Thomas Wudarski, David A. Marshall and Lloyd Hasting, 

Marijuana Odor Perception: Studies Modeled From 

Probable Cause Cases, 28 Law and Human Behavior 223, 

224 (2004)). While interesting, the study’s tentative 

conclusions do not provide a sufficient basis for us to 

overturn the District Court’s factual finding that “a smell of 

raw marijuana was emanating from the trunk area” of Green’s 

car. App. 8.
27

Stepping back from these individual factors and 

considering the “whole picture,” our question remains a fairly 

straight forward one. After the conversation at the start of the 

April 5 traffic stop, did Volk possess reasonable suspicion 

that Green was engaged in criminal activity? At that moment, 

Volk reasonably believed that Green had provided several 

misleading statements about his travel, he knew that Green’s 

trunk carried the odor of marijuana, and he knew that Green 

had several prior arrests for drug and firearm violations. This 

evidence of criminal activity was tempered by the fact that, 

only one day prior, Green consented to a search of his 

vehicle, which was found free of contraband. Reasonable 

minds may disagree over the extent to which the results of 

this search counteracted the various indicia of criminality, but 

that is precisely the point. Whatever the effect of the prior 

search, it was not so sanitizing as to make Volk’s suspicion of 

Green the following day unreasonable. We conclude that 

Volk had a “particularized and objective” basis for suspecting 

that Green was engaged in criminal activity on April 5, 

Cortez, 449 U.S. at 417, so extending the traffic stop to 

facilitate a dog sniff was permissible, Rodriguez, 135 S. Ct. at 

1615.

For the reasons explained above, we will affirm the 

decision of the District Court.