                              In the

    United States Court of Appeals
                For the Seventh Circuit
                    ____________________
No. 13-1209
UNITED STATES OF AMERICA,
                                                  Plaintiff-Appellee,

                                v.

ADRIAN RUIZ,
                                              Defendant-Appellant.
                    ____________________

        Appeal from the United States District Court for the
          Northern District of Illinois, Eastern Division.
        No. 1:11-cr-00421-1 — Robert W. Gettleman, Judge.
                    ____________________

     ARGUED JANUARY 23, 2015 — DECIDED MAY 8, 2015
                    ____________________

   Before WOOD, Chief Judge, and KANNE and TINDER, Circuit
Judges.
   TINDER, Circuit Judge. Law enforcement officers ap-
proached Adrian Ruiz’s car after they witnessed Ruiz en-
gage in what they deemed to be suspicious behavior, includ-
ing actions consistent with operating a “trap”—a concealed,
non-factory compartment in a vehicle often used to hide
drugs. Ruiz consented to the search of his car and then fol-
lowed the officers to a nearby police station where he
2                                                   No. 13-1209

showed the officers two traps in his car loaded with heroin.
Ruiz eventually pleaded guilty to possession with intent to
distribute more than 100 grams of heroin, see 21 U.S.C. §
841(a)(1), reserving the right to appeal the denial of his mo-
tion to suppress all evidence derived from his encounter
with the officers. Ruiz appeals, contending: the officers did
not have reasonable suspicion to stop his vehicle; the stop
exceeded its lawful purpose and ripened into a de facto ar-
rest; the encounter with the officers was custodial, requiring
the suppression of all statements he made prior to receiving
Miranda warnings; and he did not consent voluntarily to go
to the police station and open the traps.
    I.    BACKGROUND
    During the afternoon of October 26, 2010, Drug Enforce-
ment Agency (“DEA”) Special Agent Keith Bakewell and
DEA Task Force Officer Jay Tapia (collectively, the “offic-
ers”)—driving separate, unmarked cars but in radio com-
munication—were surveilling a storefront in Gurnee, Illi-
nois. Based upon a prior drug seizure and information from
confidential informants, the officers believed that the store
was being used by drug dealers to ply their trade. The offic-
ers saw Michael Coleman, who they knew had prior drug-
trafficking convictions, exit the rear of the store and get into
a blue Pontiac. Agent Bakewell followed Coleman as he
drove into a residential neighborhood. Bakewell, who en-
tered the neighborhood approximately a minute after Cole-
man, saw Coleman’s Pontiac parked in the middle of the
street beside a black Cadillac Escalade that was registered to
the primary target of the officers’ drug-trafficking investiga-
tion. Soon after Bakewell came into view, the two cars drove
away from each other. Bakewell followed the black Escalade
No. 13-1209                                                  3

to a strip-mall parking lot, where the black Escalade parked
next to a silver Escalade that was registered to another target
of the investigation. It appeared to Bakewell that the occu-
pants of the two Escalades were engaged in a conversation.
The officers then followed the silver Escalade as it left the
strip-mall parking lot and drove to the parking lot of another
mall, the Gurnee Mills Outlet Mall (“Gurnee Mall”). Officer
Tapia testified that, based upon his training and experience,
narcotics transactions often occur in mall parking lots be-
cause the high volume of pedestrian and vehicle traffic can
mask drug-dealing activity.
    The silver Escalade parked in the Gurnee Mall parking
lot, but nobody exited the vehicle. Agent Bakewell then saw,
for the first time, the person he would later identify as De-
fendant Ruiz walking toward the front passenger-side of the
silver Escalade. It appeared to Agent Bakewell that Ruiz was
directed to walk to the other side of the car, and Ruiz even-
tually entered the Escalade through the rear, driver-side
door. Two or three minutes later, Ruiz exited the Escalade,
walked in one direction, turned around, and then walked in
the opposite direction towards an unoccupied Honda Ac-
cord parked nearby. Ruiz entered the Accord through the
driver’s door. Agent Bakewell next saw the Accord’s rear
brake lights activate and Ruiz began manipulating “some of
the … driver controls” in the vehicle, such as those control-
ling the air conditioner, the windshield wipers, and the win-
dows. Bakewell then saw Ruiz reach behind the driver’s seat
and appear to “put something in the rear passenger” area of
the vehicle. Bakewell testified that, based upon his experi-
ence and training with the DEA, the Chicago Police Depart-
ment, and the Illinois State Police, trap compartments can
exist “[a]nywhere there is a natural void” in a vehicle and
4                                                   No. 13-1209

can be opened by manipulating the controls of a vehicle in
the manner done by Ruiz.
    Ruiz then started the Accord and pulled out of the mall
parking lot, with the officers covertly following. At this time,
Ruiz was driving in what Agent Bakewell described as a
“normal, everyday manner,” such as going “a couple of
miles an hour over the speed limit” and “signaling when he
[got] to the intersection, not before.” Officer Tapia phoned a
Gurnee Police Department (“Gurnee PD”) officer and asked
her to attempt to “develop independent probable cause for a
stop” of Ruiz’s Accord, in an effort to make Ruiz believe it
was a random traffic stop with no involvement by the DEA.
When the marked Gurnee PD squad car neared the Accord,
Ruiz began driving in a “very cautious” manner, driving
five miles an hour below the speed limit and signaling well
in advance of turns. Bakewell noted that the Accord had
Wisconsin plates but drove past the on-ramp for the inter-
state that led toward the Illinois-Wisconsin border.
   Ruiz eventually turned into a residential driveway with a
“for rent” sign in the yard. The squad car drove past the
parked Accord and continued along the residential street.
Once the marked squad car was out of sight, Agent Bake-
well—who had pulled his unmarked vehicle into a nearby
driveway—saw the Accord’s brake lights activate and then
Ruiz manipulated the driver controls and reached around to
the rear of the vehicle in the same manner as he had done in
the Gurnee Mall parking lot. Ruiz next put the Accord in re-
verse and began backing out of the driveway. The Accord
had moved only a few feet backward when the marked
squad car drove back into view; Ruiz then stopped his car
No. 13-1209                                                              5

and deactivated the brake lights, apparently shifting into
park.
    The squad car parked on the street two houses south of
Ruiz’s Accord, and the Gurnee PD officer stayed in her car.
Agent Bakewell and Officer Tapia pulled their unmarked
vehicles into curbside parking spaces to the north and south
of the driveway where Ruiz sat. Bakewell and Tapia, both in
plainclothes and not displaying weapons, approached the
driver’s window of the Accord on foot and identified them-
selves as law enforcement officers. In response to Tapia’s
questions, Ruiz said he was interested in the house adver-
tised as being for rent and he had previously been at the
Gurnee Mall visiting a furniture store.1 Tapia asked Ruiz to
get out of the car, and Ruiz did so. Upon request, Ruiz pro-
vided the officers with his driver’s license, which listed his
address as a city in southern Texas that Tapia characterized
as “a source city for narcotics.” The Accord was registered to
an address in Kenosha, Wisconsin.
    In response to Tapia’s questions, Ruiz denied having
drugs or hidden compartments in the car. Tapia asked if he
could search the car, and Ruiz consented. A ten-minute
search turned up nothing, save for two cell phones. The inte-
rior of the car was “spotless” and had no other personal ef-
fects, which the officers believed was suggestive of the car
being a “trap car” used for drug trafficking. 2 Tapia called for

1 Ruiz had parked his car near a Sears and a Sports Authority in the
Gurnee Mall parking lot. However, there was a furniture store elsewhere
in the mall.
2 The officers testified that there is a perception among drug dealers that
a car containing many personal items invites closer scrutiny by law en-
forcement.
6                                                   No. 13-1209

a canine unit to come to their location to sniff Ruiz’s car, but
none was available. Tapia then asked Ruiz if he would drive
to the nearby Waukegan police station, because Tapia (who
was a member of the Waukegan Police Department) be-
lieved he could access a canine unit there. Ruiz agreed to
drive to the station. The encounter between Ruiz and the of-
ficers in the driveway lasted a total of approximately 30
minutes.
    Because neither Ruiz nor Bakewell knew how to get to
the station, Tapia led the way in his unmarked car, followed
by Ruiz in the Accord and Bakewell in his unmarked car.
Neither officer activated his emergency lights during the
drive (or at any other time during the encounter). Ruiz main-
tained possession of his driver’s license and cell phones. The
Gurnee PD squad car did not join the procession; instead it
drove off in a different direction. At the station, Ruiz parked
in a public parking lot and exited his vehicle. While Tapia
called for a canine unit, Bakewell spoke with Ruiz. Bakewell
told Ruiz that he thought he had seen Ruiz operating a trap
in the Gurnee Mall parking lot. Ruiz responded that he was
engaged to be married and was “worried about going home
that night.” Bakewell told Ruiz if he cooperated by opening
the trap, the prosecutor would view this “act of good faith”
with favor. Ruiz initially denied that the Accord had a trap,
but after overhearing Bakewell and Tapia discuss the request
for a canine unit, Ruiz conceded the car had two traps and
agreed to open them for the officers. Approximately 10 to 15
minutes after parking in the station lot, Ruiz went through
the process of manipulating the controls and opening the
traps in the Accord, revealing heroin inside each. After fol-
lowing police procedures for retrieving and storing the
drugs, the officers escorted Ruiz into the station. Ruiz signed
No. 13-1209                                                            7

a written waiver of his Miranda rights and then made incrim-
inating statements. Thereafter, Ruiz was allowed to leave the
station.
    Approximately eight months later, a criminal complaint
was filed charging Ruiz with possession with intent to dis-
tribute more than 100 grams of heroin in violation of
§ 841(a)(1). Ruiz filed a motion to suppress, and the district
court conducted an evidentiary hearing with Tapia and
Bakewell as the only witnesses. At the conclusion of the
hearing, the judge announced that the motion was denied
because he found that the officers’ testimony (from which
the above-recounted facts were derived) was credible; the
officers had reasonable suspicion for a stop pursuant to Terry
v. Ohio, 392 U.S. 1 (1968); the officers would have let Ruiz go
if he had asked to leave; and Ruiz voluntarily consented to
the search of his car, to drive to the police station, and to
open the traps.
     On September 21, 2012, Ruiz entered a conditional guilty
plea pursuant to a written plea agreement, preserving his
right to appeal the denial of the motion to suppress. The
agreement states that, during October 2010, Ruiz completed
two transactions, whereby Ruiz sold a total of nearly 600
grams of heroin to a buyer for a total of $36,000. The buyer
subsequently complained to Ruiz about the quality of 285.9
grams of the heroin and asked for a refund of $18,000. Ruiz
agreed to the refund—perhaps because he was committed to
providing good customer service, or perhaps because he
feared the dissatisfied buyer might do something more dras-
tic than simply complain. 3 On October 26, 2010, after retriev-

3 Given that the buyer was suspected of being a member of an organiza-
tion known as the “Maniac Latin Disciples,” the latter seems more likely.
8                                                   No. 13-1209

ing the heroin from the buyer’s vehicle in the parking lot of
the Gurnee Mall, Ruiz returned to his car and placed the
bags of heroin inside two traps. Ruiz then left the parking lot
and drove toward Wisconsin with the intent to distribute the
heroin to another—perhaps less-discerning—individual.
   The district court thereafter imposed upon Ruiz a below-
Guidelines sentence of three years of imprisonment and four
years of supervised release.
    II.   DISCUSSION
    When reviewing a district court’s decision on a motion to
suppress, we review findings of historical fact for clear error
and conclusions of law (as well as mixed questions of law
and fact, such as determinations of reasonable suspicion) de
novo. Ornelas v. United States, 517 U.S. 690, 699 (1996); United
States v. Uribe, 709 F.3d 646, 649 (7th Cir. 2013). Ruiz chal-
lenges the district court’s factual finding that his consent was
voluntary, which is addressed below; otherwise, Ruiz does
not mount a serious challenge to the factual findings of the
district court, and we do not find them to be clearly errone-
ous. See United States v. Bullock, 632 F.3d 1004, 1011 (7th Cir.
2011) (“Under clear error review, we will not overturn the
district court’s factual findings unless left with a definite and
firm conviction that the district court was mistaken. We give
special deference to the district court’s credibility determina-
tions.”) (quotation omitted). Ruiz instead contends that,
even accepting the officers’ testimony as truthful, his motion
to suppress should have been granted.
    Ruiz first argues that his motion should have been grant-
ed because the officers did not have reasonable suspicion to
approach and detain his vehicle in the residential driveway.
“An investigatory stop complies with the Fourth Amend-
No. 13-1209                                                    9

ment if the brief detention is based on reasonable suspicion
that the detained individual has committed or is about to
commit a crime.” Uribe, 709 F.3d at 649–50 (citing, inter alia,
Terry, 392 U.S. at 21–22). The officers initiating the investiga-
tory stop must be able to point to “specific and articulable
facts which, taken together with rational inferences from
those facts,” suggest criminal activity. Terry, 392 U.S. at 21.
“[I]narticulate hunches” will not suffice. Id. at 22. However,
“[r]easonable suspicion is a lower threshold than probable
cause” and “considerably less than preponderance of the ev-
idence.” Bullock, 632 F.3d at 1012 (quotations omitted). “Rea-
sonable suspicion is a less demanding standard than proba-
ble cause not only in the sense that reasonable suspicion can
be established with information that is different in quantity
or content than that required to establish probable cause, but
also in the sense that reasonable suspicion can arise from in-
formation that is less reliable than that required to show
probable cause.” Alabama v. White, 496 U.S. 325, 330 (1990).
This is an objective standard, based upon the facts available
to the officers at the moment of the seizure. Terry, 392 U.S. at
21–22.
    “[I]n determining whether officers had the requisite par-
ticularized suspicion for a Terry stop, we do not consider in
isolation each variable of the equation that may add up to
reasonable suspicion. Instead, we consider the sum of all of
the information known to officers at the time of the stop.”
Matz v. Klotka, 769 F.3d 517, 523 (7th Cir. 2014) (citation omit-
ted), cert. denied, 83 U.S.L.W. 3720 (U.S. Apr. 27, 2015). In
other words, “courts examine the totality of the circumstanc-
es known to the officer at the time of the stop, including the
experience of the officer and the behavior and characteristics
of the suspect.” Bullock, 632 F.3d at 1012 (quotation omitted).
10                                                 No. 13-1209

Reasonable suspicion can arise from “behavior that may in
other circumstances be considered innocent; in other words,
context matters.” Matz, 769 F.3d at 523.
    The government presented numerous facts in support of
its position that reasonable suspicion existed at the time the
officers approached Ruiz in the driveway. The officers had
observed a series of suspicious encounters between three dif-
ferent vehicles—one was driven by an individual with drug
convictions and the other two were registered to the subjects
of an ongoing drug-trafficking investigation. These encoun-
ters culminated with Ruiz entering one of the vehicles in a
mall parking lot—a type of location favored by drug dealers.
Prior to entering the car, Ruiz appeared to be redirected
from the front passenger-side to the rear driver-side. After
exiting the car, Ruiz appeared to have trouble locating his
car, perhaps because he simply forgot where he parked or
perhaps because he was not very familiar with his car. Upon
entering his car, Ruiz engaged in a series of steps that—
based upon the training and experience of Agent Bakewell—
were consistent with the operation of a trap. The district
judge specifically credited Bakewell’s experience and train-
ing in this regard, which was permissible. See United States v.
Arvizu, 534 U.S. 266, 273 (2002) (“This process [of determin-
ing whether reasonable suspicion exists] allows officers to
draw on their own experience and specialized training to
make inferences from and deductions about the cumulative
information available to them that might well elude an un-
trained person.”) (quotation omitted).
    Once it was clear Ruiz knew a marked squad car was fol-
lowing him, he passed the on-ramp to the interstate which
would have taken him to Wisconsin (where his car was reg-
istered), and instead drove into a residential neighborhood
No. 13-1209                                                  11

and pulled into a driveway of a house being advertised for
rent. After the marked police car drove out of sight, Ruiz re-
peated the same steps as he had done in the mall parking lot
consistent with the operation of a trap. Ruiz then began
backing out of the driveway, which is inconsistent with the
behavior of a person looking at the house as a potential rent-
er. When the squad car drove back into view, Ruiz immedi-
ately stopped and put his car into park, which is consistent
with the behavior of someone attempting to evade notice by
the police.
    In isolation, each of Ruiz’s actions might be more suscep-
tible to an innocent explanation than the not-so-innocent ex-
planation ascribed to it by the officers. We doubt that any
one of Ruiz’s actions, as witnessed by the officers, would
alone give rise to the suspicion necessary to justify a Terry
stop—including his parking-lot meeting with a suspected
drug dealer and taking actions consistent with the operation
of a trap. Cf. United States v. Bohman, 683 F.3d 861, 864 (7th
Cir. 2012) (holding that “a mere suspicion of illegal activity
about a place, without more, is not enough to justify stop-
ping everyone emerging from that property”); United States
v. Carrillo, 269 F.3d 761, 767 (7th Cir. 2001) (“[T]he existence
of a vehicle trap in itself is not enough to establish probable
cause—traps may, of course, be used for legitimate purpos-
es….”). But when all of Ruiz’s actions are viewed in concert
and through the lens of experienced law enforcement offic-
ers, the innocent explanations begin to look less likely and
the not-so-innocent explanations begin to look more likely.
See Arvizu, 534 U.S. at 277–78 (“Undoubtedly, each of these
factors alone is susceptible of innocent explanation, and
some factors are more probative than others. Taken together,
we believe they sufficed to form a particularized and objec-
12                                                  No. 13-1209

tive basis for [the officer]’s stopping the vehicle, making the
stop reasonable within the meaning of the Fourth Amend-
ment.”); United States v. Riley, 493 F.3d 803, 809 (7th Cir.
2007) (“Although … all of these taken separately might not
justify a stop, we do not evaluate the circumstances in isola-
tion. Furthermore, these circumstances must be viewed
through the lens of [the investigating detective], an experi-
enced officer.”) (citation omitted).
     Ruiz emphasizes that the officers did not witness any
drugs change hands or Ruiz carry a bag which might have
contained drugs. However, a drug dealer who hides his
merchandise from public view is not thereby rendered im-
mune from a narcotics-based Terry stop. See Bullock, 632 F.3d
at 1012–14 (holding that, despite seeing nothing change
hands, police officers had reasonable suspicion to detain a
suspect based upon an anonymous tip and observations that
the suspect made several brief visits to residences and host-
ed several short meetings in his vehicle, which an officer tes-
tified was indicative of drug-dealing activity). Instead, con-
sidering the totality of the circumstances, we think that, by
the time the officers approached Ruiz’s car in the driveway,
the officers could point to “specific and articulable facts
which, taken together with rational inferences from those
facts,” suggested Ruiz was engaged in illegal activity. Terry,
392 U.S. at 21; see id. at 22 (holding that reasonable suspicion
may exist when an officer observes individuals “go through
a series of acts, each of them perhaps innocent in itself, but
which taken together warranted further investigation”). The
district court correctly held that the officers had reasonable
suspicion to initiate a traffic stop to investigate for the pres-
ence of narcotics in the car.
No. 13-1209                                                    13

    The next issue is whether, as contended by Ruiz, the in-
vestigatory stop exceeded its lawful purpose and ripened
into a de facto arrest. “A Terry stop based on reasonable sus-
picion can ripen into a de facto arrest that must be based on
probable cause if it continues too long or becomes unreason-
ably intrusive.” Bullock, 632 F.3d at 1015. “The investigation
following a Terry stop must be reasonably related in scope
and duration to the circumstances that justified the stop in
the first instance so that it is a minimal intrusion on the indi-
vidual’s Fourth Amendment interests.” Matz, 769 F.3d at 525
(quotations omitted); see Florida v. Royer, 460 U.S. 491, 500
(1983) (“[A]n investigative detention must be temporary and
last no longer than is necessary to effectuate the purpose of
the stop. Similarly, the investigative methods employed
should be the least intrusive means reasonably available to
verify or dispel the officer’s suspicion in a short period of
time.”).
    With respect to the duration of the stop, there is no rigid
time limit placed on Terry stops. Bullock, 632 F.3d at 1015.
And a defendant’s actions can contribute to a permissible
extension of the stop. For example, in United States v. Vega,
72 F.3d 507 (7th Cir. 1995), we held that a 62-minute delay
was reasonable given that the defendant initially consented
to a search of his garage, but then changed his mind. Id. at
515–16; see United States v. Goodwin, 449 F.3d 766, 772 (7th
Cir. 2006) (holding that duration of Terry stop was reasona-
ble when the defendant “was … the co-author of the prolon-
gation that is the fulcrum of his Fourth Amendment claim”).
Likewise, assuming reasonable suspicion exists (as it did
here), a reasonable delay attributable to arranging for a ca-
nine unit to conduct a sniff may permissibly extend the du-
ration of a stop. See Vega, 72 F.3d at 516; cf. Rodriguez v. Unit-
14                                                      No. 13-1209

ed States, --- S. Ct. ----, No. 13-9972, 2015 WL 1780927, at *6–*7
(U.S. Apr. 21, 2015) (holding that police may not extend an
otherwise-completed traffic stop, absent reasonable suspi-
cion, in order to conduct dog sniff).
    At the outset of the stop, Ruiz gave answers which in-
creased rather than allayed the officers’ suspicions. Ruiz
claimed to be parked in the driveway because he was inter-
ested in renting the house, but, as the district court noted, his
“backing out of that driveway [after] the police car passed
him … is inconsistent with looking at a house he might want
to rent.” Also suspicious was Ruiz’s claim that he was at the
mall to visit a furniture store, when he did not park within
view of any furniture store and, unbeknownst to Ruiz, the
officers had witnessed Ruiz meet with the subject of their
narcotics investigation in the parking lot. The officers’ suspi-
cions were increased further by Ruiz’s Texas driver’s license,
combined with his car being registered in Wisconsin and
containing no personal items. In short, the first few minutes
of the stop only served to increase the officers’ reasonable
suspicion that Ruiz was operating a trap car, and this justi-
fied further investigation by the officers. See United States v.
Robinson, 30 F.3d 774, 784 (7th Cir. 1994) (holding that fur-
ther investigation was justified based in part upon a defend-
ant’s misleading answers at the outset of a Terry stop).
    The remainder of the time in the driveway was devoted
to Tapia’s search of Ruiz’s car and the officers’ attempt to
summon a canine unit for assistance. The district court
found that Ruiz voluntarily consented to the search of his
car. This finding is not challenged by Ruiz, 4 and the finding

4 Ruiz only challenges the voluntariness of his subsequent consent to
drive to the station and open the traps, as discussed infra.
No. 13-1209                                                 15

was not clearly erroneous. In the words of the district court,
Ruiz’s voluntary consent to the search was “consistent with
the entire modus operandi … of the officers … mak[ing] this
defendant feel as comfortable as possible while they were
talking to him.”
    We have previously held that “the relevant focus in de-
termining whether the seizure [in the form of a traffic stop]
was reasonable in duration is the time between its initiation
and the [defendant’s] consent [to search the vehicle].” United
States v. Taylor, 596 F.3d 373, 376 (7th Cir. 2010); see United
States v. Muriel, 418 F.3d 720, 725 (7th Cir. 2005) (“The … ap-
propriate focus … is the time that elapsed between the initial
stop and [the defendant]’s consent to search; consent renders
a search reasonable under the Fourth Amendment unless
given involuntarily….”). The officers detained Ruiz for less
than 20 minutes prior to obtaining his consent to search the
car, which is a reasonable duration, given that there is noth-
ing in the record to suggest that the officers acted less than
diligently. See Bullock, 632 F.3d at 1015 (holding that 30-40
minute detention while police executed search warrant was
reasonable when there was no indication the officers unnec-
essarily prolonged the search).
    Tapia’s ten-minute search of Ruiz’s car came up empty,
which is not surprising given that traps are designed to
elude an officer making a quick search. Accordingly, it was
reasonable for the officers to attempt to arrange for a dog
sniff of the car. Upon learning that a mobile canine unit was
not readily available, Tapia asked Ruiz if he would drive to
the nearby Waukegan police station. Tapia was a member of
the Waukegan Police Department, not the Gurnee police
force. It was reasonable for Tapia to believe that he could ar-
16                                                  No. 13-1209

range for a canine unit quicker while at his home station
than at a residential driveway in the neighboring town of
Gurnee. Had Ruiz refused the request to go to the station,
we would be presented with a different case. But Ruiz con-
sented to go (whether his consent was voluntary is an issue
we will address below). His consent to the initial search and
to go to the station, as well as the diligence of the officers,
made the otherwise lengthy encounter—30 minutes in the
driveway, 15 minutes to drive to the station, and 10-15
minutes at the station—fall within the bounds of what is ac-
ceptable for a Terry stop. See Vega, 72 F.3d at 515–16. We find
that the officers’ investigative detention of Ruiz lasted “no
longer than [was] necessary to effectuate the purpose of the
stop,” and the investigative methods employed by the offic-
ers were “the least intrusive means reasonably available to
verify or dispel the officer’s suspicion in a short period of
time.” Royer, 460 U.S. at 500.
    Ruiz next contends that his encounter with the officers
was custodial, requiring the suppression of all statements he
made prior to receiving Miranda warnings at the station.
Law enforcement officers must advise suspects of their con-
stitutional right to remain silent and to have counsel present
before subjecting them to custodial interrogation. See Miran-
da v. Arizona, 384 U.S. 436, 471–72 (1966). To determine
whether an interrogation was custodial, we ask whether,
“given the totality of the circumstances, a reasonable person
would have felt at liberty to terminate the interrogation and
leave.” United States v. Littledale, 652 F.3d 698, 701 (7th Cir.
2011) (citing Yarborough v. Alvarado, 541 U.S. 652, 662 (2004)).
This “inquiry is objective, and relevant factors include
whether the encounter occurred in a public place; whether
the [individual] consented to speak with the officers; wheth-
No. 13-1209                                                   17

er the officers informed the individual that he was not under
arrest and was free to leave; whether the individual was
moved to another area; whether there was a threatening
presence of several officers and a display of weapons or
physical force; and whether the officers’ tone of voice was
such that their requests were likely to be obeyed.” Id.
    On the “custodial” side of the ledger, the officers failed to
inform Ruiz that he was not under arrest and was free to
leave. Also, the manner in which the officers’ vehicles—
unmarked though they may have been—flanked Ruiz’s car
in the driveway and during the drive to the station subtly
undermined the message that Ruiz was free to leave. Ruiz
was asked to move from the driveway to the police station,
although any custodial aspect of this was mitigated by the
fact that Ruiz consented to the relocation (whether this con-
sent was voluntary will be discussed below), and was per-
mitted to drive his own car.
    On the “non-custodial” side of the ledger, the entire en-
counter took place in public view. The district court found
that the officers spoke to Ruiz in a calm, courteous manner
throughout the encounter, which was designed to make
Ruiz feel at ease. The officers were in plainclothes, with no
display of weapons or force. The officers’ unmarked vehicles
did not block the driveway, and the marked squad car was
parked across the street, two houses away. The Gurnee po-
lice officer in the squad car did not approach the driveway at
any time, and she drove away in a different direction when
Ruiz and the officers left the area. As the district court noted,
the fact that the officers let Ruiz drive his own car to the sta-
tion and retain possession of his driver’s license and phones
is a strong indicator that Ruiz was not in custody. When he
18                                                No. 13-1209

arrived at the police station, Ruiz parked in a public lot ra-
ther than a secure lot. The subsequent conversation between
Bakewell and Ruiz occurred beside Ruiz’s car in the public
lot.
    On balance, we think that Ruiz was not in custody prior
to being Mirandized at the station. See id. at 701–02 (holding
that suspect was not in custody at the time of his confession
at a police station even though the questioning officers did
not tell the suspect that he was free to leave, because the
suspect consented to be interviewed, there was no display of
force or physical touching, the officers used a monotone tone
of voice, and the suspect was told he was not under arrest);
United States v. Thompson, 496 F.3d 807, 811 (7th Cir. 2007)
(same, when officers calmly questioned suspect in his home
for a few hours prior to his confession, telling him that de-
fendants who cooperated received lighter punishments);
United States v. Wyatt, 179 F.3d 532, 536–37 (7th Cir. 1999)
(same, when suspect voluntarily accompanied officers to ar-
ea outside bar and then to police station despite patdown
search and questioning; the suspect was uncuffed and there
was no other show of force by the officers).
    Ruiz’s final argument is that his consent to drive to the
station and then open the traps was not voluntary. The dis-
trict court found that Ruiz’s consent was voluntary, and
therefore this portion of the encounter “doesn’t really impli-
cate the Fourth Amendment.” Ruiz challenges this finding,
contending that “any reasonable person in [his] circum-
stances would have been incapable of rendering voluntary
consent.”
No. 13-1209                                                             19

     Whether an individual’s consent is voluntary is a factual
determination, which we review for clear error. 5 United
States v. Richards, 741 F.3d 843, 847 (7th Cir. 2014). To deter-
mine whether consent was provided voluntarily, we consid-
er the totality of the circumstances, including Ruiz’s age, ed-
ucation, and intelligence; whether he was advised of his con-
stitutional rights; how long he was detained prior to consent;
whether he consented immediately or after police made sev-
eral requests; whether the police used physical coercion; and
whether he was in custody. Id. at 848; see Schneckloth v.
Bustamonte, 412 U.S. 218, 226–27 (1973). We review these fac-
tors in light of the information known to the officers at the
time, and “[o]ur determination does not depend on a single
controlling factor, but carefully considers ‘all of the sur-
rounding circumstances.’” Richards, 741 F.3d at 848 (quoting
Schneckloth, 412 U.S. at 226).
    Ruiz was 10 days shy of his 20th birthday on the day of
the encounter; his responses to the officers demonstrated
him to be reasonably intelligent and educated. The officers
did not inform Ruiz of his constitutional rights until after he
opened the traps. Ruiz was with the officers in the driveway
approximately 30 minutes prior to agreeing to go to the sta-
tion, and then approximately 10-15 minutes at the station
prior to opening the traps. Ruiz consented immediately
when asked to go to the station, although he initially denied
having traps in the car and only agreed to open them after


5 The government contends that Ruiz forfeited the argument that his
consent was not voluntary by not raising it before the district court, and
therefore we should review the district court’s finding for plain error
rather than clear error. Because we find no clear error, see infra, we need
not consider whether Ruiz forfeited the argument.
20                                                 No. 13-1209

overhearing the officers discuss the request for a canine unit.
The officers used no physical coercion, displayed no weap-
ons, and spoke to Ruiz in a calm, conversational manner. Fi-
nally, as discussed above, we have decided that Ruiz was
not in custody during the encounter—although our decision
assumed that Ruiz’s consent to go to the station was volun-
tary, so we assign little-to-no weight to this factor.
    As with the determination of whether Ruiz was in custo-
dy, there are some factors tending to show his consent was
involuntary, most notably, the failure to inform Ruiz of his
constitutional rights and the questioning of Ruiz about the
presence of a trap after he had denied that his car contained
one. There are other factors tending to show Ruiz’s consent
was voluntary, such as the fact that the officers used no
physical coercion, they spoke to him in a calm, conversa-
tional manner, and Ruiz readily agreed to go to the station.
This is a factual determination, see Schneckloth, 412 U.S. at
227, which the district court resolved by finding that Ruiz’s
consent to go to the station and open the traps was volun-
tary. Considering the totality of the circumstances, we are
not “left with the definite and firm conviction that a mistake
has been committed,” Anderson v. City of Bessemer City, 470
U.S. 564, 573 (1985), and we therefore hold that this finding
was not clearly erroneous. See United States v. Strache, 202
F.3d 980, 986–87 (7th Cir. 2000).
   The district court did not err in denying Ruiz’s motion to
suppress. Accordingly, the district court’s judgment is
AFFIRMED.
