                       PUBLISHED


UNITED STATES COURT OF APPEALS
             FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,             
                Plaintiff-Appellee,
               v.                          No. 11-4863
TERRENCE C. VAUGHAN,
             Defendant-Appellant.
                                      
       Appeal from the United States District Court
     for the Eastern District of Virginia, at Richmond.
             Henry E. Hudson, District Judge.
                  (3:11-cr-00051-HEH-1)

                 Argued: October 25, 2012

               Decided: November 29, 2012

   Before SHEDD, DAVIS, and WYNN, Circuit Judges.



Affirmed by published opinion. Judge Davis wrote the opin-
ion, in which Judge Shedd and Judge Wynn joined.


                        COUNSEL

ARGUED: George Alfred Townsend, GEORGE A. TOWN-
SEND, IV, PLLC, Richmond, Virginia, for Appellant. Erik
Sean Siebert, OFFICE OF THE UNITED STATES ATTOR-
NEY, Richmond, Virginia, for Appellee. ON BRIEF: Neil H.
2                    UNITED STATES v. VAUGHAN
MacBride, United States Attorney, Alexandria, Virginia, for
Appellee.


                             OPINION

DAVIS, Circuit Judge:

   Appellant Terrence C. Vaughan ("Vaughan") was driving
a rental car with McKinley Scott ("Scott") in Virginia when
Virginia State Police Officer Steven Homiak ("Homiak")
pulled him over for speeding. Based on Scott’s apparent ner-
vousness and the presence of four cellular phones in the cen-
ter console (two of which were pre-paid phones that Homiak
associated with "people involved with drugs"), and on Scott’s
and Vaughan’s conflicting explanations for their travels,
Homiak called in a drug-detection dog. The dog arrived 13
minutes after the initiation of the traffic stop. It alerted by the
trunk two to three minutes later; the resulting search revealed
830.6 grams of cocaine. Vaughan filed a motion to suppress
which the district court denied. He then pled guilty, reserving
his right to appeal the motion’s denial, and was sentenced to
120 months’ incarceration. For the following reasons, we
affirm.

                                   I.

   On January 5, 2011, Homiak, a ten-year veteran of the Vir-
ginia State Police, was conducting a routine assignment on
Interstate 95 in Greenville, Virginia. Homiak observed a
white Ford Taurus pass him traveling northbound at a high
rate of speed. After pacing the vehicle at 79 miles per hour in
a posted 70-mile per hour zone, Homiak commenced a traffic
stop at 10:43 a.m.1
    1
   Homiak testified as to the timing of the initial traffic stop and the
events that followed it, and there was no objection to that testimony.
                      UNITED STATES v. VAUGHAN                             3
   After Vaughan pulled the vehicle over to the shoulder,
Homiak approached it, asked Vaughan for his driver’s license
and registration, and explained the reason for the stop.
Vaughan produced a Virginia driver’s license, as well as a
rental agreement for the vehicle. The passenger of the vehicle,
Scott, had his seat leaned back such that he was almost lying
horizontally. Homiak noticed that although Vaughan’s
demeanor appeared normal, Scott was exhibiting "high levels
of nervousness"; he was shaking and breathing heavily, his
hands were trembling, and Homiak "could see his heart beat-
ing through his shirt." J.A.2 41-42. Homiak also noticed four
cellular telephones in the vehicle’s center console, at least two
of which were pre-paid phones, which Homiak testified are
"especially" popular "with people involved with drugs"
because no personal information need be provided to obtain
the phones. J.A. 42, 58. He stated that he could tell which
phones were pre-paid phones because they had "[t]he word
‘TracFone’ on [them]." J.A. 43.

   Vaughan accompanied Homiak to the police cruiser, where
Vaughan sat in the front passenger seat while Homiak ran his
information. Homiak testified that he uses this "investigative
technique" for both officer safety, and to separate the driver
from the passengers to see if the occupants will give conflict-
ing stories. J.A. 45.

  While running Vaughan’s license and other routine crimi-
nal history checks through the law enforcement database,
Vaughan and Homiak engaged in conversation.3 During their
conversation, Vaughan informed Homiak that he left Peters-
burg that morning and traveled to Emporia, Virginia, to pick
up Scott. When asked where in Emporia he came from, how-
  2
     Citations to the "J.A." refer to the Joint Appendix filed by the parties
in this appeal.
   3
     The record is unclear as to whether Homiak specifically asked
Vaughan about the purpose of his travels, or whether Vaughan volun-
teered that information.
4                     UNITED STATES v. VAUGHAN
ever, Vaughan could not recall and said that Scott lived in
Stony Creek, which Homiak testified is 13 or 14 miles north
of Emporia.

   After confirming—approximately six minutes into the traf-
fic stop—that Vaughan possessed a valid driver’s license,4
Homiak went back to the rental vehicle to speak with Scott.
He did this for two reasons: first, to obtain Scott’s identifica-
tion and check for outstanding warrants, and second, to "find
out what his travel plans were," because of his initial nervous
behavior. J.A. 46-47. When Homiak asked Scott for his iden-
tification, Scott produced a Virginia identification card and
acted even more nervously than he had initially. Specifically,
Scott continued to shake, his voice cracked, and he paused
before every answer, saying "uhmm" before he responded in
a way that appeared to Homiak to be "a stalling technique."
J.A. 47. Moreover, when asked about the pair’s travels that
day, Scott claimed that they had driven from Charlotte, North
Carolina, and that they "went down yesterday, stayed the
night, and now [were] headed back." J.A. 48. Based on the
conflict between Scott’s and Vaughan’s stories, Homiak’s
suspicions were greatly aroused. Homiak’s interaction with
Scott was two or three minutes long, and ended by 10:52 a.m.,
nine minutes after he initiated the traffic stop.

   Homiak returned to his police cruiser and sent an instant
message requesting that a nearby trooper come to Homiak’s
location with a drug-detection dog.5 Homiak requested the
canine unit at or about 10:52 a.m., and it responded to the
   4
     Homiak testified that he had to run Vaughan’s information through his
computer twice because the first time he ran the information, "it came
back not on file." J.A. 46.
   5
     Although Homiak was a trained canine officer and had a certified drug-
detection dog in the rear of his vehicle, he requested assistance from
another canine unit in the area because (1) the handler would evaluate the
alert without knowing all that Homiak knew, allowing for a more objec-
tive check on the vehicle; and (2) having a second trooper perform the
sweep allowed Homiak to continue the traffic stop without prolonging it.
                    UNITED STATES v. VAUGHAN                         5
scene of the traffic stop at 10:56 a.m., within four minutes of
the instant message and within 13 minutes of the traffic stop’s
commencement.

   During the time Homiak was awaiting the arrival of the
canine unit, Homiak ran Scott’s information on his computer
to check for warrants. During this same time, Homiak also
began filling out a contact report form, part of which must be
completed "on every traffic stop," and other parts of which
must be completed after requesting consent to search a vehi-
cle or a canine sweep of a vehicle. J.A. 79. Homiak testified
that the checks on Scott’s information, which were conducted
simultaneously with the filling out of the contact report, lasted
"a couple minutes." J.A. 51.

   Upon seeing the canine unit arrive at the scene, Vaughan
became extremely nervous, his breathing became heavy, his
heart began "pounding through his shirt," and his hands
shook. J.A. 52. As the canine unit began its sweep of the vehi-
cle, Homiak continued his computer checks of Scott, contin-
ued to fill out the contact report, and continued to ask
Vaughan clarifying questions. Throughout this process,
Homiak was in possession of Vaughan’s identifying informa-
tion and the vehicle rental agreement.

   The canine sweep lasted two to three minutes until, at
10:59 a.m., the dog alerted to the apparent presence of narcot-
ics in the vehicle. Based on the positive alert, Homiak advised
Vaughan that the troopers were going to search the vehicle.
Vaughan continued to display "very high levels of nervous-
ness, continued with the shaking and the heavy breathing,"
and attempted to explain the positive alert by stating that he
had "touched some marijuana the night before and he hasn’t
changed his clothes." J.A. 55-56. Vaughan also informed
Homiak that there was a gun in the vehicle’s center console.6
  6
   The record does not disclose what role, if any, the discovery of the
handgun played in the prosecution of this case.
6                  UNITED STATES v. VAUGHAN
A search of the vehicle revealed a handgun in the center con-
sole and 830.6 grams of cocaine.

   Vaughan was indicted for conspiracy to distribute cocaine
under 21 U.S.C. §§ 841(a), 841(b)(1)(B)(ii), and 846, and for
possession with intent to distribute cocaine hydrochloride
under 21 U.S.C. §§ 841(a) and 841(b)(1)(B)(ii). He filed a
motion to suppress the cocaine found in his car, arguing that
Homiak failed to diligently pursue the justification for the ini-
tial stop, and lacked reasonable suspicion to prolong it. After
a hearing, the district court denied the motion. Vaughan then
pled guilty pursuant to a plea agreement to one count of con-
spiracy to distribute cocaine, and was sentenced to 120
months in prison. Although Vaughan generally waived his
right to appeal in his plea agreement, he reserved his right to
appeal the district court’s denial of his motion to suppress. He
timely appealed.

                               II.

   Vaughan does not challenge the legality of the initial traffic
stop. Rather, he argues that Homiak’s separate questioning of
him and Scott impermissibly "prolong[ed] the traffic stop
beyond the necessary time to issue a traffic summons."
Vaughan Br. 7. He contends that Homiak lacked reasonable
suspicion to do so, because "[i]f a passenger’s nervous
appearance . . . combined with the Trooper’s conclusion that
the occupants of a vehicle have made different statements
regarding their travels justifies an investigatory detention,
then practically any traffic stop justifies an investigatory
detention." Vaughan Br. 8-9.

   The government argues in response that Homiak diligently
pursued the goal of investigating the suspected traffic viola-
tion, and did not impermissibly prolong it. In the alternative,
the government argues that Homiak had reasonable suspicion
of criminal activity to justify a brief extension of the stop.
                   UNITED STATES v. VAUGHAN                    7
   "In considering the district court’s denial of a motion to
suppress, we review the district court’s legal determinations
de novo and its factual determinations for clear error. When
the district court has denied a suppression motion, we must
construe the evidence in the light most favorable to the gov-
ernment." United States v. Mubdi, 691 F.3d 334, 339 (4th Cir.
2012) (citations and internal quotation marks omitted).

   The Fourth Amendment guarantees "[t]he right of the peo-
ple to be secure in their persons, houses, papers, and effects,
against unreasonable searches and seizures." U.S. Const.
amend. IV. "Temporary detention of individuals during the
stop of an automobile by the police, even if only for a brief
period and for a limited purpose, constitutes a ‘seizure’ of
‘persons’ within the meaning of this provision." Whren v.
United States, 517 U.S. 806, 809-10 (1996). "Because an
ordinary traffic stop is ‘a limited seizure more like an investi-
gative detention than a custodial arrest,’ we employ the
Supreme Court’s analysis for investigative detention used in
Terry v. Ohio, 392 U.S. 1 (1968), to determine the limits of
police conduct in routine traffic stops." United States v.
Guijon-Ortiz, 660 F.3d 757, 764 (4th Cir. 2011) (quoting
United States v. Rusher, 966 F.2d 868, 875 (4th Cir. 1992)).

    Under Terry’s "dual inquiry," after asking whether
    the officer’s action was "justified at its inception,"
    Rusher, 966 F.2d at 875, we ask whether the contin-
    ued stop was "sufficiently limited in scope and dura-
    tion to satisfy the conditions of an investigative
    seizure." Florida v. Royer, 460 U.S. 491, 500 (1983)
    (plurality opinion). With regard to scope, "the inves-
    tigative methods employed should be the least intru-
    sive means reasonably available to verify or dispel
    the officer’s suspicion in a short period of time." Id.
    With regard to duration, although the reasonable
    duration of a traffic stop "cannot be stated with
    mathematical precision," United States v. Branch,
    537 F.3d 328, 336 (4th Cir. 2008), a stop may
8                  UNITED STATES v. VAUGHAN
    become "unlawful if it is prolonged beyond the time
    reasonably required to complete [its] mission." Illi-
    nois v. Caballes, 543 U.S. 405, 407 (2005). Thus, we
    evaluate "whether the police diligently pursued a
    means of investigation that was likely to confirm or
    dispel their suspicions quickly, during which time it
    was necessary to detain the defendant." United
    States v. Sharpe, 470 U.S. 675, 686 (1985). To pro-
    long a traffic stop "beyond the scope of a routine
    traffic stop," an officer "must possess a justification
    for doing so other than the initial traffic violation
    that prompted the stop in the first place." Branch,
    537 F.3d at 336. This requires "either the driver’s
    consent or a ‘reasonable suspicion’ that illegal activ-
    ity is afoot." Id.

    Although the scope and duration components of
    Terry’s second prong require highly fact-specific
    inquiries, the cases make possible some generaliza-
    tions. When a police officer lawfully detains a vehi-
    cle, "police diligence involves requesting a driver’s
    license and vehicle registration, running a computer
    check, and issuing a ticket." United States v.
    Digiovanni, 650 F.3d 498, 507 (4th Cir. 2011). The
    officer may also, "in the interest of personal safety,"
    request that the passengers in the vehicle provide
    identification, at least so long as the request does not
    prolong the seizure. United States v. Sori-
    ano–Jarquin, 492 F.3d 495, 500–01 (4th Cir. 2007).
    Similarly, the officer may "inquir[e] into matters
    unrelated to the justification for the traffic stop," Ari-
    zona v. Johnson, 555 U.S. 323, 333 (2009), and may
    take other actions that do not constitute "searches"
    within the meaning of the Fourth Amendment, such
    as conducting a dog-sniff of the vehicle, Caballes,
    543 U.S. at 409, but again only "so long as those
    inquiries [or other actions] do not measurably extend
    the duration of the stop." Johnson, [555 U.S. at 333].
                      UNITED STATES v. VAUGHAN                           9
Guijon-Ortiz, 660 F.3d at 764-65. Additionally, "a police offi-
cer may as a matter of course order the driver of a lawfully
stopped car to exit his vehicle." Maryland v. Wilson, 519 U.S.
408, 410 (1997) (citing Pennsylvania v. Mimms, 434 U.S. 106
(1977) (per curiam)). That rule, the justification for which is
officer safety, extends to passengers, as well. Wilson, 519
U.S. at 414-15.

   When determining whether reasonable suspicion exists, we
"must look at the ‘totality of the circumstances’ . . . to see
whether the detaining officer has a ‘particularized and objec-
tive basis’ for suspecting legal wrongdoing." United States v.
Arvizu, 534 U.S. 266, 273 (2002) (citation omitted).

                                   III.

   Based on the totality of the undisputed evidence before the
district court summarized above, we conclude that reasonable
suspicion of criminal activity existed at the moment Homiak
determined that Vaughan’s and Scott’s explanations of their
travels conflicted, between six and nine minutes after the stop
commenced.7 Homiak could thus briefly extend the stop for
a period of time reasonably necessary to confirm or dispel his
suspicions. Here, Homiak promptly obtained confirmation of
his suspicions through the canine sweep of the vehicle.
Accordingly, the district court properly denied Vaughan’s
motion to suppress.

   Vaughan argues that Homiak lacked reasonable suspicion
to extend the traffic stop because "[i]f a passenger’s nervous
appearance . . . combined with the Trooper’s conclusion that
  7
   Under our precedents, through that moment, Homiak had diligently
pursued the purpose of the initial stop, and his continued detention of the
vehicle and its occupants had not become an investigative detention
wholly unrelated to the initial speeding violation. Because we hold that
Homiak had reasonable suspicion to prolong the stop before his question-
ing of Scott was complete, we do not reach the issue of when (if at all)
the stop would have become such an investigative detention.
10                UNITED STATES v. VAUGHAN
the occupants of a vehicle have made different statements
regarding their travels justifies an investigatory detention,
then practically any traffic stop justifies an investigatory
detention." Vaughan Br. 8-9. But that is not a fair statement
of the "totality of the circumstances" here. By the time Scott
explained his travels in a way that conflicted with Vaughan’s
explanation, additional factors known to Homiak included: (1)
Scott’s apparent nervousness when Homiak first spoke to
Vaughan, and his increased nervousness when Homiak later
spoke alone to Scott; (2) the presence of four cellular phones,
two of which were pre-paid and which Homiak, based on his
experience, associated with people involved with drugs; and
(3) Vaughan’s modification of the explanation for his travels,
first saying he was coming from Emporia and then from
Stony Creek. We discuss each of these factors in turn,
together with the contradiction between Vaughan’s and
Scott’s explanations of their travels.

   First, Scott’s behavior was nervous and evasive.
"[N]ervous, evasive behavior is a pertinent factor in determin-
ing reasonable suspicion," Illinois v. Wardlow, 528 U.S. 119,
124 (2000), and this Court has pointed to such behavior as
contributing to reasonable suspicion in the context of traffic
stops. See, e.g., Mubdi, 691 F.3d at 337-38, 344 (hands shak-
ing, appearing unusually scared); United States v. Mason, 628
F.3d 123, 129 (4th Cir. 2010) (sweating, unusual nervous-
ness); Branch, 537 F.3d at 338 (hands shaking, failure to
make eye contact). Here, Homiak noted that at the outset of
the traffic stop, Scott, reclined in his seat, "was shaking" and
"breathing heavily," "[h]is hands were trembling," and "[y]ou
could see his heart beating through his shirt." Scott’s nervous-
ness increased when Homiak went to talk to him again. He
was shaking, his voice cracked, and he would stall and say
"uhmm" before answering questions. Scott’s nervous behav-
ior, which was at least as pronounced as the behavior
                      UNITED STATES v. VAUGHAN                          11
described in Mubdi, Mason, and Branch, was a valid factor
contributing to reasonable suspicion.8

   Second, Homiak had noticed four cellular phones in the
center console of Vaughan’s vehicle, at least two of which
were pre-paid phones known as "TracFones." In Homiak’s
experience, "these phones are typical . . . with people
involved with drugs" because no identification information
need be provided to obtain such phones. Officers are entitled
"to draw on their own experiences . . . to make inferences
from and deductions about the cumulative information avail-
able," Arvizu, 534 U.S. at 267, and it is therefore "appropriate
for courts ‘to credit the practical experience of officers who
observe on a daily basis what transpires on the street,’"
Branch, 537 F.3d at 336-37 (citation omitted).

   We are mindful that the Sixth Circuit, in the context of a
reasonable-suspicion analysis stemming from a traffic stop,
recently declined "to hold that a particular brand or model of
cell phone is more suspicious than another, particularly when
the ‘pay-as-you-go’ feature is just as likely to attract those
who cannot afford a monthly contract as it may be to attract
drug couriers." United States v. Stepp, 680 F.3d 651, 666 (6th
Cir. 2012). In Stepp, however, the only cellular phone in the
car was one pre-paid phone; previously, the Sixth Circuit had
held that "[t]hree cell phones in one car" can "contribute to
reasonable suspicion of criminal activity," though it is a weak
   8
     We note that the testimony describing Scott’s nervous behavior was
significantly more supportive of reasonable suspicion than that displayed
by the defendant in Branch. As observed by the dissent in that case,
"[m]ost people when they are pulled over by the police are nervous."
Branch, 537 F.3d at 346 (Gregory, J., dissenting). Here, however, Scott’s
behavior was not limited to mere shaking hands and lack of eye contact,
but included "excessive signs of nervousness," id., such as his cracking
voice and repeated stalling before answering Homiak’s questions. In short,
this is not a case where the government has "us[ed] whatever facts are
present, no matter how innocent, as indicia of suspicious activity." United
States v. Foster, 634 F.3d 243, 248 (4th Cir. 2011).
12                 UNITED STATES v. VAUGHAN
indicator. United States v. Townsend, 305 F.3d 537, 544 (6th
Cir. 2002).

   Here, not only were there four total cellular phones in a car
containing just two people, but those phones appeared to
Homiak to be of multiple types: pre-paid and standard. The
Sixth Circuit’s legitimate concern that labeling a particular
type of phone as one that "attract[s] drug couriers" is not as
pronounced here, where vehicle occupants possess both types
of phones. It is thus sufficient to hold that where four cellular
phones are present in a car with just two people, and at least
two of those phones are of the pre-paid type known to the
detaining officer to be associated with narcotics trafficking,
the presence of the phones constitutes a valid factor in a rea-
sonable suspicion analysis.

   Third, Vaughan changed his own explanation for his trav-
els. After Homiak permissibly instructed Vaughan to come to
his patrol car, the two men discussed the circumstances of
Vaughan’s trip. Vaughan first said he was coming from
Emporia, and then clarified that he was actually coming from
Stony Creek (which, according to Homiak, is 13 or 14 miles
north of Emporia). Given the fact that Vaughan’s clarification
was relatively minor (rather than an outright contradiction),
the value of this clarification in contributing to reasonable
suspicion is weak, but the changing story remains a valid fac-
tor contributing to reasonable suspicion.

   Finally, as discussed above, Vaughan’s explanation of his
travels flatly contradicted Scott’s. In Mason, we held that
where a driver and passenger were separately questioned
about the purpose of their travels, conflicting answers "indi-
cat[ed] that they were covering up the place where they had
stayed and the real purpose of their travel." 628 F.3d at 129.
Mason also noted that this factor "especially" contributed to
reasonable suspicion that criminal activity was afoot. Id. The
same is true here.
                  UNITED STATES v. VAUGHAN                   13
   Viewed in their totality, these circumstances were sufficient
to generate Homiak’s reasonable suspicions that criminal
activity was afoot no later than the moment Scott volunteered
an explanation for his travels that conflicted with Vaughan’s.
This occurred at some point between the sixth and ninth min-
utes of the traffic stop. As a result, Homiak was justified in
briefly extending the stop (rather than issuing the speeding
citation to Vaughan immediately) to confirm or allay his sus-
picions of criminal activity. The delay was reasonable; by the
sixteenth minute of the traffic stop, the drug-detection dog
had arrived on the scene, swept the vehicle, and alerted, and
Homiak had informed Vaughan that he would immediately
conduct a vehicle search.

                              IV.

  For the reasons set forth, we affirm the district court’s
denial of Vaughan’s motion to suppress.

                                                   AFFIRMED
