USA v. Flores-Mendivil

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WO
IN THE UNITED STATES DISTRICT COURT
FOR THE DISTRICT OF ARIZONA
United States of America,
Plaintiff,
v.
Mario Humberto Flores-Mendivil,
Defendant.
No. CR-25-01233-TUC-AMM (EJM)
REPORT AND RECOMMENDATION
Pending before the Court is a Motion to Suppress for Lack of Reasonable Suspicion
(Doc. 50). The defendant, Mario Humberto Flores-Mendivil, is charged in a three-count
indictment with Conspiracy to Transport Illegal Aliens for Profit, in violation of 8 U.S.C.
§§ 1324(a)(1)(A)(v)(I), (a)(1)(A)(ii), & (a)(1)(B)(i), and two counts of Transportation of
Illegal Aliens for Profit, in violation of 8 U.S.C. §§ 1324(a)(1)(A)(ii) & (a)(1)(B)(i). (Doc.
27.) On September 8, 2025, the defendant filed a Motion to Suppress for Lack of
Reasonable Suspicion arguing that Border Patrol agents stopped his vehicle without
reasonable suspicion that criminal activity was afoot; therefore, the evidence obtained from
the unlawful stop should be suppressed. (Doc. 50.)
On November 3, 2025, the Court held an evidentiary hearing on the Motion to
Suppress. Border Patrol Agent Casey Sartin and Border Patrol Agent Dalton Myers
testified. Based on that testimony and the other evidence presented, the Court recommends
that the District Court grant the motion.
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I. THE EVIDENTIARY HEARING
A. Border Patrol Agent Casey Sartin
1. Direct examination
Casey Sartin has been a Border Patrol Agent for fifteen years and has been stationed
in Douglas, Arizona his entire career. (Hr’g Tr. 11/3/25 at 5-6, Doc. 75.) Agent Sartin
attended the Border Patrol academy for six months and has regular trainings four times a
year. (Id. at 6.)
On Saturday February 1, 2025, Agent Sartin was on duty from 6:00 a.m. to 2:00
p.m. (Id. at 7.) He started his shift by attending a muster where agents were provided with
information about criminal activity that occurred the prior day. (Id.) Agent Sartin was
advised that there was a group of about five suspected illegal aliens “that were potentially
coming up to Highway 80” around mile marker 405 near Skelton Canyon. (Id.) Because
of the mountain range in the area, illegal aliens commonly appear around that mile marker.
(Id. at 7-8.) Illegal alien activity is common in that area on Highway 80 because it is
extremely remote and there are no cameras. (Id. at 9.) There is “a long stretch [of road]
where [there are] miles and miles of pretty much nothing besides some random ranch
houses here and there[.]” (Id.) Highway 80 is a two-lane road that runs for about eighty
miles from Douglas, Arizona to Interstate 10 which leads into New Mexico. (Id. at 12-
13.) Traffic on Highway 80 on the weekends is slower than weekdays because there are
not “as many people going back and forth to work the ranches.” (Id. at 12.)
After muster, Agent Sartin went to mile marker 398 on Highway 80 to look for
vehicles that may be loaded with illegal aliens. (Id. at 12-13.) Agent Sartin parked his
marked Border Patrol vehicle on the side of the road at that mile marker because “it’s a
straightaway stretch” which allowed him to view vehicles travelling in either direction on
Highway 80. (Id. at 13, 17-18.) Agent Sartin noticed two vehicles travelling southwest on
Highway 80 toward Douglas “that looked like they were driving together.” (Id. at 13.)
The first vehicle, a Pontiac SUV, had temporary tags which made Agent Sartin suspicious
based on his experience. (Id. at 15.) The second vehicle, a Chrysler sedan, had a California
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license plate affixed to the front bumper of the vehicle. (Id. at 13.) Agent Sartin decided
to follow the vehicles because it seemed “out of the norm” for a vehicle from California to
be “going through that area.” (Id. at 13-16.) The vehicles “kept that same proximity” to
each other which was suspicious because they were travelling on a long and flat
straightaway where vehicles can easily pass one another. (Id.) There is not “a double
yellow line that requires people not to pass” and Agent Sartin does not recall much, if any,
“oncoming traffic heading towards New Mexico that would have prevented them from
passing[.]” (Id.)
After following the vehicles for about ten miles, Agent Sartin pulled into the
opposing lane of traffic to pass the Chrysler and get his vehicle behind the SUV. (Id. at 17-
19.) As Agent Sartin was passing the Chrysler, he tried to see if there were passengers or
the driver’s reaction “but the windows were extremely tinted.” (Id. at 17.) Because of the
window tint, all he could see was “basically a shape” of the driver. Agent Sartin “really
wanted to take a look” at the Pontiac SUV that had temporary tags. (Id. at 18.) It took
Agent Sartin a while to pull behind the Pontiac SUV because “[t]here wasn’t a big gap
between the two vehicles.” (Id. at 18-19.) Once he got his vehicle behind the Pontiac
SUV, Agent Sartin ran a records check on the temporary tag. The records check revealed
that the Pontiac SUV was recently registered in Tucson, Arizona. (Id. at 19.)
Agent Sartin then pulled alongside the Pontiac SUV in the opposing lane of traffic
to look at the driver and in the rear passenger area. (Id. at 19.) He could not see into that
area because “the vehicle had dark tint in the rear windows[.]” (Id. at 19-20.) In Agent
Sartin’s experience, someone driving many miles and hours would appear relaxed. (Id. at
20.) However, the driver of the Pontiac SUV appeared nervous because she was “tightly
gripping the steering wheel” and was stiff. (Id. at 20.) In Agent Sartin’s experience, drivers
are usually nervous when he pulls “alongside of them, especially if they’re involved in
something illicit.” (Id. at 20.) The driver was “looking straight ahead, almost acting like”
she was not even aware he was there. (Id.) But the driver’s “stiffness” made it obvious to
Agent Sartin that she was “extremely aware” that he was looking at her. (Id.)
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After Agent Sartin saw the reaction of the driver, he decided that he “was definitely
going to pull them over for an immigration inspection[.]” (Id. at 21.) Once again, it was
difficult for Agent Sartin to pull behind the SUV because the “Chrysler was again still just
following at a pretty close space.” (Id.) Agent Sartin had to “kind of nudge [his] way in
to have that safety zone” because they were travelling about 65 miles per hour, and it felt
“a lot safer having a couple car lengths between vehicles.” (Id. at 21.)
Agent Sartin requested assistance from other agents in the area because “it’s kind of
common for these vehicles to protect . . . the illegal aliens. There’s commonly a scout or
another vehicle that drives with these to where they take it out of the driver’s hands and
they secure what they’re picking up. So one driver doesn’t even know where they’re going
to be picking up these illegal aliens.” (Id. at 21-22.) Based on his experience, Agent Sartin
“knew one of these vehicles was going to have illegal aliens in it.” (Id. at 22.)
Agent Sartin specifically asked Agent Myers, who was at mile marker 384, to get
behind and follow the Chrysler sedan. (Id. at 22.) Agents commonly park at mile marker
384 because “you can see quite a long stretch of the highway” and it’s at a higher elevation.
Agent Sartin and Agent Myers decided to stop both vehicles “relatively close to each other
at the same time.” (Id. at 25.) At around mile marker 377, Agent Sartin activated his
vehicle’s emergency lights and siren; the Pontiac SUV pulled to the side of the road “within
a reasonable time.” (Id.) Agent Myers pulled over the Chrysler about 100 yards west of
where Agent Sartin made his stop. (Id.)
Agent Sartin believed the vehicles were travelling in tandem based on the following
facts. First, the distance between the vehicles and the number of miles they maintained
this distance. (Id. at 26.) Second, the difficulty he had getting between the vehicles. (Id.)
Third, the temporary tags on the Chrysler which is common for vehicles involved in alien
smuggling because the “vehicles are often bought at a cheaper rate” to minimize loss if the
vehicle is ultimately seized by law enforcement. (Id. at 27.) Fourth, the Chrysler was
registered in Tucson and agents do not see too “many people from Tucson coming from
New Mexico using that route of highway.” (Id.) Fifth, it was unusual to see a vehicle
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registered in Tucson travelling southwest on Highway 80 because “if you were coming
from New Mexico or Texas, you would typically stay on Interstate 10 to go to Tucson.”
(Id.) Travelling on Highway 80 “would be a long roundabout” and “there isn’t much reason
to be on Highway 80 going that route.” (Id. at 27-28.) Similarly, a vehicle registered in
California that is coming from New Mexico or Texas would typically stay on Interstate 10
to return to California. (Id. at 28.) Sixth, “there’s nothing out there” where the stop
occurred. (Id.) Seventh, neither vehicle had a connection to Douglas, Arizona, and
vehicles “coming to visit people in Douglas . . . typically, do not end up on the east side of
Douglas.” (Id.)
2. Cross-examination
Highway 80 is not a dirt road or ranch road; it is a well maintained two-lane paved
road that runs east and west. (Id. at 32-33.) Highway 80 connects Douglas, Arizona to
Interstate 10, which runs to New Mexico and Texas. (Id. at 33.)
The Chrysler sedan with the California license plate “was trailing the Pontiac” SUV
which had temporary tags. (Id.) The vehicles were not speeding or driving too slowly,
they did not make any unusual turns or stops, and they did not try to avoid Border Patrol
agents. (Id. at 34-35.)
Agent Sartin’s report does not mention how close the Chrysler sedan was to the
Pontiac SUV either when he first saw the vehicles or as he followed them for ten miles.
(Id. at 34.) His report also does not mention that the Crysler was “tailgating” the SUV.
(Id.) Agent Sartin’s report also does not mention where the recent crossing of a group of
illegal aliens occurred, the time of day the group was seen, or what they looked like. (Id.
at 36.) Agents did not have any information that either a Pontiac SUV or Chrysler sedan
was seen near the border. (Id. at 37.) Agent Sartin never had a clear view of the driver of
the Chrysler. (Id. at 40.) However, his report does not mention the Chrysler “having
problems with tint[.]” (Id. at 38.)
Agent Sartin did not see the vehicles travelling northeast on Highway 80; he only
saw them travelling southwest toward Douglas, Arizona. (Id. at 36.) He did not know
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where either vehicle was coming from. (Id.) Both vehicles were lawfully registered and
neither was a rental vehicle. (Id. at 37.)
In 2018, Agent Sartin was formally disciplined for false reporting to a law
enforcement officer who responded to a traffic accident. (Id. at 42.) Agent Sartin initially
told the officer that he was wearing a seatbelt at the time of the accident. He later admitted
that he was not wearing a seatbelt. (Id. at 43.)
3. Re-direct examination
Agent Sartin believes that a Pontiac SUV has more cargo capacity than a Chrysler
sedan. (Id. at 43-44.) When Agent Sartin was driving beside the Pontiac SUV, he did not
have a clear view of the rear passenger area of the vehicle because the rear windows were
tinted. (Id. at 44.) As a result, he could not tell if the rear passenger area was occupied or
unoccupied. (Id.)
4. The Court’s examination
The Chrysler was about “a car length and a half” behind the Pontiac SUV from the
time Agent Sartin first saw the vehicles until when he pulled his vehicle behind the Pontiac
SUV to perform the traffic stop. (Id. at 46.) The Chrysler was also “a car length and a
half” behind Agent Sartin’s vehicle once he got behind the Pontiac SUV. (Id. at 46-47.)
Agent Sartin’s report does not mention that the Chrysler was “a car length and a half”
behind the Pontiac SUV. (Id. at 52.)
The purpose of tandem driving is to “separate the people that are recruiting the
drivers.” (Id. at 47.) A ”handler” coordinates with people in Mexico; the handlers “don’t
necessarily trust the people they recruit because they don’t typically know them from cities
of Tucson and Phoenix. So they recruit a driver that’s going to be taking the risk if they
are caught. And, obviously, the handler kind of isolates themselves from the risk.” (Id. at
47.) During tandem driving, it is common for the vehicle that is not transporting illegal
aliens to “take off” to mislead law enforcement. (Id. at 47-48.)
With respect to the significance of the defendant travelling southwest on Highway
80, rather than northeast away from the border, sometimes a driver will “go all the way
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east” on Interstate 10 to not attract the attention of Border Patrol by going northeast on
Highway 80 and coming back southwest on the same road. (Id. at 48.) However, a handful
of times a driver will travel northeast on Highway 80, pick up illegal aliens, and then travel
southwest on Highway 80. (Id. at 49.)
After he was shown photographs of the SUV, Agent Sartin changed his earlier
testimony regarding whether the tinting on the rear windows of the Pontiac SUV prevented
him from seeing into the rear passenger area. He testified that “[i]f there were people
sitting upright” in the Pontiac SUV, he “would have been able to tell how many passengers
were sitting up.” (Id. at 51.) He could not see if people were “laying on the floorboard or
under carpet” in the rear passenger area. (Id.) However, his inability to see if people were
on the floor of the Pontiac SUV was not because of the tinting; rather, it stemmed from the
fact that he was “looking across” his vehicle into the Pontiac which was travelling at 65
miles per hour. (Id.)
B. Border Patrol Agent Dalton Myers
1. Direct Examination
Dalton Myers has been a Border Patrol Agent for three-and-a-half years. (Id.
at 54.) He attended the Border Patrol Academy for six months and has quarterly trainings.
(Id.) Agent Dalton has had several assignments during his career, including patrolling in
the Douglas area of responsibility. (Id.)
On February 1, 2025, Agent Dalton worked from 6:00 a.m. to 2:00 p.m. (Id. at 55.)
He began his shift at muster where agents were informed about a group of suspected illegal
aliens that were seen the prior day somewhere between mile markers 392 and 402 on
Highway 80. (Id.) That area is desolate and has a good line of sight and not a lot of traffic.
(Id. at 55-56.) For those reasons, it is common area to patrol because there are groups of
suspected illegal aliens in the area every day. (Id. at 56.) There are culverts and brush on
the side of Highway 80 that people can hide in while waiting for a vehicle to pick them up.
(Id.) The area is “pretty far away from the actual border itself, so response time is a little
harder to get out there.” (Id. at 55.)
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At around 7:30 a.m., Agent Myers went to mile marker 384 on Highway 80. (Id. at
57.) He had a clear view of Highway 80. (Id. at 58.) There is hardly any traffic on
Highway 80 other than local ranchers. (Id.) There is not typically any tourist traffic. (Id.)
There is a “very small town called Rodeo” just across the New Mexico border that has “a
handful of people that live there.” (Id. at 58-59.)
Agent Sartin radioed that “[h]e had two vehicles riding in tandem around mile
marker 400 that [were] heading back towards Douglas[.]” (Id. at 59.) Agent Myers
“radioed back” to Agent Sartin that he “would back him up if [Agent Sartin] ended up
stopping one of them.” (Id.) Agent Myers “saw the a blue Torrent with the Arizona paper
tag first, followed by Agent Sartin, and then followed by the Chrysler 300 with California
plates[.]” (Id.) The Chrysler was “almost bumper to bumper” with Agent Sartin’s patrol
vehicle. (Id. at 60.) Agent Myers found that driving behavior unusual because normally
people “back off” from a Border Patrol vehicle. (Id.)
Agent Myers started following the Chrysler in his marked Border Patrol vehicle.
(Id.) He requested a records check on the Chrysler which revealed that it was registered
“to a Mario out of San Jose, California[.]” (Id. at 60-61.) He found it strange that the
vehicle had an actual registered owner because normally vehicles registered in California
that are encountered in that area are rental vehicles. (Id. at 61.) It also did not make sense
for a vehicle from California to be on Highway 80 because “there’s nothing out there to do
or see.” (Id.) The records check also revealed that the Chrysler had crossed into the United
States through the Nogales Port of Entry earlier in the day and also passed through the
Border Patrol checkpoint on Interstate 19. (Id.) Agent Myers found it suspicious that the
Chrysler came through the Nogales Port of Entry, travelled north on Interstate 19, and then
ended up travelling southwest on Highway 80. (Id. at 63.) He also found it suspicious that
the vehicles were riding in tandem for a long period of time. (Id.)
Agent Myers performed his traffic stop on the Chrysler “about a mile up the road”
from where Agent Sartin stopped the Pontiac SUV. (Id. at 64.) The driver of the Chrysler
was the defendant. (Id. at 65.)
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2. Cross Examination
Agent Myers agreed that the TECS report reflects that the Chrysler crossed into the
United States and went through the Border Patrol checkpoint on January 30, 2025, three
days prior to the traffic stop. (Id. at 65-68.)
Highway 80 is a well maintained two-lane paved road that connects Douglas,
Arizona with Interstate 10, which leads to New Mexico and Texas. (Id. at 69-70.) The
population of Douglas is about 15,000 people. (Id. at 69.) The Chrysler and SUV could
have been coming from Interstate 10, New Mexico, or Texas. (Id. at 70.)
Agents were advised at muster that there was a group of three to five suspected
illegal aliens who had not been apprehended. (Id. at 71.) Agents were not told when these
individuals were spotted, where they crossed the border, or about any vehicle(s) that may
be picking up these individuals. (Id. at 71.) The Douglas area of responsibility for Border
Patrol is about a thousand-square-mile area. (Id.)
Agent Myers followed the vehicles and Agent Sartin for about eight to nine miles
before he stopped the Chrysler. (Id.) The vehicles were not speeding or driving too slowly,
they were not driving erratically, and they did not make any unusual turns. (Id. at 71-72.)
Both vehicles were “appropriately registered,” and neither was a rental vehicle. (Id. at 72.)
Rental vehicles “can be suspicious to Border Patrol” agents. (Id. at 73.) Agent Myer’s
report does not mention the distance between the Chrysler and Agent Sartin’s patrol
vehicle, the window tint on either vehicle, or that the driver of the Chrysler appeared
nervous. (Id. at 72-73.) There were “no problems with the [window] tint” on either
vehicle; Agent Myers could see through the windows of both vehicles. (Id. at 73.)
3. Re-Direct Examination
When Agent Myers runs a records check on a vehicle that he is following, he is not
provided with the actual TECS report. (Id. at 75.) The dispatch operator told him over the
radio that the Chrysler went through the port of entry and checkpoint earlier that morning.
(Id.) Agent Myers had not seen the TECS report prior to his testimony. (Id.)
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4. The Court’s Examination
Agent Myers believes that Agent Sartin likely heard the radio communication about
the Chrysler crossing through the port of entry and checkpoint earlier that day because he
was on the same radio frequency. (Id. at 77.) That information was significant to Agent
Myers because “there’s no reason that a vehicle, if their destination was Douglas, would
need to go all the way up to I-10 and then take it all the way over to Road Forks and then
down to [Highway] 80 east,” because there are multiple ways to get to Douglas before
Highway 80. (Id. at 78.) That route adds another hour to get to Douglas. (Id.)
With respect to significance of the vehicles travelling southwest on Highway 80
toward the border, Agent Myers believes it would have been almost more suspicious for a
vehicle that has taken I-10 “to turn around and go back to I-10 and do a quick turnaround
versus just continuing into Douglas and never hitting” any of the license plate readers. (Id.
at 79.) It is a common practice for alien smugglers to use tandem drivers. (Id.) The
vehicle that has the illegal aliens is usually in front and the vehicle behind is used to “kind
of stop the agent from getting behind the vehicle that has the illegal aliens in it.” (Id.) That
said, this “was the first time [Agent Myer’s had] ever seen a car drive like this[.]” (Id. at
84.) The driver of the second vehicle will often drive erratically to get the agent to stop
that vehicle so the load vehicle gets away. (Id.)
Agent Myers has never seen a vehicle tailgate a law enforcement vehicle like the
Chrysler did here. (Id. at 80.) Again, it is more common for the second vehicle to speed
away, slow down, swerve, or do whatever they can to get law enforcement to pull over that
vehicle instead of the smuggling vehicle. (Id.) The driver of Chrysler did not engage in
any such driving behavior. (Id. at 84.) In Agent Myers’ experience, it is difficult to tie the
scout vehicle to the load vehicle as was done in this case. (Id. at 81.)
II. DISCUSSION
A. Fourth Amendment—In General
“The Fourth Amendment prohibits ‘unreasonable searches and seizures’ by the
Government, and its protections extend to brief investigatory stops of persons or vehicles
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that fall short of traditional arrest.” United States v. Arvizu, 534 U.S. 266, 273 (2002)
(citing Terry v. Ohio, 392 U.S. 1, 9 (1968); United States v. Cortez, 449 U.S. 411, 417
(1981)). “The Fourth Amendment applies to all seizures of the person” and a person is
“seized” when “a police officer accosts an individual and restrains his freedom to walk
away.” United States v. Brignoni-Ponce, 422 U.S. 873, 878 (1975). In order for law
enforcement officers to conduct a lawful vehicle stop, there must be reasonable suspicion
that “criminal activity may be afoot.” Terry v. Ohio, 392 U.S. 1, 30 (1968); United States
v. Sokolow, 490 U.S. 1, 7 (1989).
“Reasonable suspicion is defined as ‘a particularized and objective basis for
suspecting the particular person stopped of criminal activity.’” United States v. Cotterman,
709 F.3d 952, 968 (9th Cir. 2013) (en banc) (quoting United States v. Cortez, 449 U.S. 411,
417–18 (1981)). “The reasonable-suspicion standard is not a particularly high threshold to
reach.” United States v. Valdes-Vega, 738 F.3d 1074, 1078 (9th Cir. 2013). Although “a
mere hunch is insufficient to justify a stop, the likelihood of criminal activity need not rise
to the level required for probable cause, and it falls considerably short of satisfying a
preponderance of the evidence standard.” Id. (quoting Arvizu, 534 U.S. at 274) (citations
and internal quotation marks omitted). “Rather, reasonable suspicion exists when an
officer is aware of specific, articulable facts which, when considered with objective and
reasonable inferences, form a basis for particularized suspicion.” United States v. Montero-
Camargo, 208 F.3d 1122, 1129 (2000) (quoting Cortez, 449 U.S. at 418). This
particularized suspicion is two-fold, including “the totality of the circumstances” and
“reasonable suspicion that the particular person being stopped has committed or is about
to commit a crime.” Id. (emphasis in original).
B. Totality of the Circumstances
When determining if there was reasonable suspicion for a vehicle stop, the court
must consider the “totality of the circumstances of each case to see whether the detaining
officer has a particularized and objective basis for suspecting legal wrongdoing.” United
States v. Arvizu, 534 U.S. 266, 273 (2002). The Supreme Court has recognized that “[a]ny
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number of factors may be taken into account in deciding whether there is reasonable
suspicion to stop a car in the border area.” United States v. Brignoni-Ponce, 422 U.S. 873,
884–85 (1975). The factors an officer may consider include: (1) the characteristics of the
area in which they encounter the vehicle; (2) the proximity to the border; (3) the usual
traffic patterns on the particular road; (4) previous experience with alien traffic; (5)
information regarding recent illegal border crossings in the area; (6) driving behavior, such
as erratic driving or obvious attempts to evade officers; (7) the behavior and appearance of
the driver; and (8) aspects of the vehicle itself. Id. at 884–85 (citations omitted). This list
is non-exhaustive. “Not all of these factors must be present or highly probative in every
case to justify reasonable suspicion.” United States v. Valdes-Vega, 738 F.3d 1074, 1079
(9th Cir. 2013).
The Supreme Court has held that courts should not engage in a “divide-and-conquer
analysis” when reviewing the factors considered by law enforcement. Arvizu, 534 U.S. at
274. Stated another way, it is inappropriate to view factors in isolation and to give no
weight to factors which may have an innocent explanation. Arvizu, 534 U.S. at 273–275.
The Supreme Court has held that “even when factors considered in isolation from each
other are susceptible to an innocent explanation, they may collectively amount to a
reasonable suspicion.” United States v. Berber-Tinoco, 510 F.3d 1083, 1087 (9th Cir. 2007)
(citing Arvizu, 534 U.S. at 274). Therefore, what may seem to be innocuous conduct when
viewed in isolation may be appropriately considered when analyzing the totality of the
circumstances. Arvizu, 534 U.S. at 273–75; see also Cotterman, 709 F.3d at 970 (“It is not
our province to nitpick the factors in isolation but instead to view them in the totality of
the circumstances.”).
Although an “an officer’s experience may furnish the background against which the
relevant facts are to be assessed[,] … ‘experience’ does not in itself serve as an independent
factor in the reasonable suspicion analysis.” Montero-Camargo, 208 F.3d at 1131. That
said, when looking at the “totality of the circumstances” the court “allows officers to draw
on their own experience and specialized training to make inferences from and deductions
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about the cumulative information available to them that ‘might well elude an untrained
person.’” Id. (quoting United States v. Cortez, 449 U.S. 411, 418 (1981)). “In other words,
an officer's experience may furnish the background against which the relevant facts are to
be assessed, as long as the inferences he draws are objectively reasonable.” United States
v. Montero-Camargo, 208 F.3d, 1122, 1131 (2000). As a result, “the facts supporting
reasonable suspicion must be filtered through the lens of the [law enforcement officer’s]
training and experience” and a court must give “due weight” to factual inferences drawn
by officers. United States v. Valdes-Vega, 738 F.3d 1074, 1079 (9th Cir. 2013).
III. ANALYSIS
The instant motion turns on the credibility of Agent Sartin’s testimony. Agent
Sartin clearly had a hunch that the vehicles were smuggling illegal aliens when he decided
to follow the vehicles. He then attempted to gather facts to support his hunch. While some
of those facts are true, one important fact is clearly not true, and the truth of other important
facts is suspect. As a result, the Court finds Agent Sartin’s testimony incredible on
important facts that led to him to conclude that he had a reasonable suspicion to stop the
vehicles. Additionally, there are facts relied on by both agents that are inconsistent with
the agents’ experience of how alien smugglers operate. For these reasons, the Court
concludes that there was not reasonable suspicion to stop the defendant’s vehicle.
A. Agent Sartin’s Credibility
The Court first notes that the formal discipline that resulted from Agent Sartin’s
false reporting to the law enforcement officer who responded to a traffic accident is a
significant blemish on Agent Sartin’s record. As a result, it is fair to view Agent Sartin’s
testimony through that lens.
The most troubling portion of Agent Sartin’s testimony was his inability to see if
there were people in the rear passenger area of the SUV because of the window tint. On
direct examination, he testified that he could not see into the passenger area of the SUV
because “the vehicle had dark tint in the rear windows[.]” (Hr’g Tr. 11/3/25 at 19-20, Doc.
75.) On re-direct examination, he again testified that he could not see if there were
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passengers in the SUV because the rear windows were tinted. (Id. at 44.) After being
shown photographs of the SUV – where the passenger seats are clearly visible through the
rear windows -- and asked pointed questions by the Court, Agent Sartin changed his
testimony. He testified that: “[I]f there were people sitting upright” in the Pontiac SUV,
he “would have been able to tell how many passengers were sitting up.” (Id. at 51.) He
added that he could not see if people were “laying on the floorboard or under carpet” in the
rear passenger area. However, he conceded that his inability to see if people were on the
floor of the SUV was not because of the tinting; rather, it stemmed from the fact that he
was “looking across” his vehicle into the Pontiac which travelling at 65 miles per hour.
(Id.)
Agent Sartin’s purported inability to see if there were passengers in the rear
passenger area of the SUV because of the window tint was a significant factor in his
decision to stop the vehicle. His report reflects that as well as his initial testimony. It is
now clear that the tint on the passenger windows of the SUV is not a factor in the reasonable
suspicion analysis. The Court was not presented with an explanation for Agent Sartin’s
about-face in his testimony. As a result, the Court has no choice to conclude that Agent
Sartin concocted the story about the dark tint on the SUV’s passenger windows to justify
the stop of the vehicles.
Additionally, Agent Sartin’s report omits key facts that he identified during his
testimony that led to his conclusion that he had a reasonable suspicion to stop the vehicles.
Law enforcement officers are trained to write detailed reports to aid them in remembering
information that will become relevant at a suppression hearing and/or trial. And that
hearing or trial can occur many months (like here, ten months) or even years after the
criminal activity. Therefore, Agent Sartin’s omission of key facts in his report calls into
question the veracity of his testimony about these facts.
First, Agent Sartin testified that the Chrysler sedan had heavily tinted windows and
he could only see the shape of the driver. However, his report does not mention the
Chrysler “having problems with tint[.]” (Hr’g Tr. 11/3/25 at 38, Doc. 75.) In fact, Agent
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Myers testified that he could see through the windows of both vehicles and his report does
not mention the tint on the windows of either vehicle. (Id. at 72-73.) Agent Sartin’s
reasonable suspicion for the stop was based, in part, on the fact that the Chrysler’s heavily
tinted windows obstructed his view of the driver, which is common tactic used for vehicles
involved in alien smuggling. The truth of that fact is suspect.
Second, and perhaps more importantly, although Agent Sartin’s report states that the
vehicles were “driving in tandem,” the report does not mention the distance between the
vehicles or that the Chrysler was “tailgating” the SUV. Those omissions are startling
because Agent Sartin’s testimony makes clear that the Chrysler’s consistent and continuous
driving one-and-a-half car lengths behind the SUV was the lynchpin for stopping the
defendant’s vehicle. Specifically, he testified that he concluded that the vehicles were
driving in tandem driving because of the short distance between the vehicles when he first
saw them and while he followed them for ten miles.1 The absence of any mention of the
distance between the vehicles in Agent Sartin’s report, written shortly after the stop, casts
doubt on the veracity of his testimony ten months later on this important issue.
B. The aspects of the vehicles, the tandem driving, and the driver’s behavior.
Agent Myers found it “strange” that the Chrysler was registered to an “actual
owner” in California. He testified that rental vehicles are suspicious to Border Patrol agents
and when agents suspect that a vehicle with a California license plate is involved in alien
smuggling, the registration almost always comes back to a rental vehicle. And that is
especially the case in the area on Highway 80 where the stop occurred. Thus, the
registration of the Chrysler to an actual owner in California is not consistent with the way
alien smugglers operate.
The alleged tandem driving is also not consistent with Agent Sartin’s experience
of how alien smugglers operate because the suspected load vehicle (the Pontiac SUV) was
1 It is worth noting that the sedan was clearly not “tailgating” the SUV because
Agent Sartin testified that there was enough space between the vehicles for him to see the
California license plate on the front bumper of the sedan which was travelling around 65
miles per hour.
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travelling in front of the suspected scout vehicle (the Chrysler sedan). Agent Sartin
explained that a “handler” coordinates with people in Mexico. (Hr’g Tr. 11/3/25 at 47,
Doc. 75.) The handlers “don’t necessarily trust the people they recruit” to drive the load
vehicle “because they don’t typically know them from cities of Tucson and Phoenix. So
they recruit a driver that’s going to be taking the risk if they are caught, and, obviously, the
handler kind of isolates themselves from the risk.” (Id.) Agent Sartin further explained
that when tandem driving is used to transport illegal aliens, “[t]here’s commonly a scout or
another vehicle that drives” with the load vehicle to “take it out of the driver’s hands and
secure what they’re picking up. So one driver doesn’t even know where they’re going to
be picking up these illegal aliens.” (Id. at 21-22.)
Although Agent Sartin’s testimony is not crystal clear on this point, the Court’s
understanding of Agent Sartin’s experience with tandem driving is that load drivers do not
know the location where the illegal aliens will be picked up and dropped off because alien
smuggling organizations do not know or trust the load drivers. The organization will “take
it out of the [load] driver’s hands and secure what they’re picking up” (i.e., the illegal
aliens), by having the load vehicle follow the scout vehicle to the pick-up and drop-off
locations.2 (Id. at 21-22.) Agent Sartin’s testimony clearly shows that he suspected that
the Pontiac SUV was the load vehicle for the following reasons: (1) a SUV has more cargo
capacity than a sedan so he pulled next to the SUV to look in the rear passenger area to
check for passengers either seated upright or concealing themselves; (2) the temporary tag
on the SUV was consistent with the practice of alien smugglers buying cheap vehicles
shortly before the smuggling event to minimize loss if the vehicle transporting illegal aliens
is ultimately seized by law enforcement; (3) Agent Sartin was definitely going to stop the
SUV when he observed that the driver was nervous, which made him suspicious that there
were illegal aliens in the SUV; and (4) he positioned his patrol vehicle between the SUV
and the Chrysler so he could stop the vehicle that he believed contained the contraband
2 If the government believes that the Court’s understanding of Agent Sartin’s
experience with tandem driving is incorrect, it was the government’s burden to make it
crystal clear.
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(i.e., the illegal aliens). Based on Agent Sartin’s experience with tandem driving and his
suspicion that the SUV was the load vehicle, the Chrysler trailing the SUV weighs against
the government in the reasonable suspicion analysis.
In addition to the suspected scout vehicle travelling behind the suspected load
vehicle being inconsistent with the Agent Sartin’s experience with tandem driving, the
Chrysler’s failure to pass the SUV, slow down, or make a turn, is inconsistent with the
tactics used by scout vehicles. Agent Sartin did not testify that continued tandem driving
while the vehicles are being followed by a Border Patrol agent is a tactic used by alien
smugglers. He testified that the scout vehicle will “take off” or use other tactics to try to
mislead Border Patrol agents. Similarly, Agent Myers testified that at some point the scout
vehicle almost always slows down, speeds up, or turns off the road to divert the attention
of Border Patrol agents from the load vehicle. Additionally, Agent Myers testified that he
has never seen tandem driving where a vehicle tailgates a Border Patrol vehicle like the
Chrysler did here. He found that driving behavior unusual because normally people “back
off” from a Border Patrol vehicle. Moreover, Agent Sartin did not testify that he has
encountered that type of driving behavior during an alien smuggling event. Thus, the
absence of any attempt by the defendant to divert or mislead Border Patrol agents or engage
in other driving behavior consistent with a scout vehicle also weighs against the
government in the reasonable suspicion analysis.
Against this backdrop, there are innocuous reasons and fair inferences that can be
drawn for why the Chrysler did not pass the SUV. Agent Sartin testified that when his
vehicle was parked at mile marker 398 on Highway 80, he was able to observe the tandem
driving for a mile or two because he was located on a long straightaway. It stands to reason
that if Agent Sartin could see the vehicles from that distance on this straightaway, the
drivers of both vehicles could see his marked patrol vehicle parked on the side of Highway
80. Moreover, it is fair to say that laypeople do not know that a Border Patrol agent cannot
stop their vehicle based on a traffic violation such as speeding. As a result, it makes sense
that the Chrysler did not pass the SUV as the vehicles were approaching Agent Sartin’s
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location. The same is true during the ten mile stretch while Agent Sartin followed the
vehicles. Agent Sartin testified that the speed limit was 65 miles per hour (and 55 miles
per hour in some areas) on Highway 80. He also testified that he was driving about 65
miles per hour when driving beside the SUV. Thus, it makes sense that the defendant was
not going to exceed the speed limit to pass the SUV when Agent Sartin was behind the
defendant’s vehicle or when Agent Sartin was in front of his vehicle. In fact, if the
defendant had passed the SUV and exceeded the speed limit at any point, it would have
been even more suspicious because, once again, both agents testified that the scout vehicles
often speed up or engage in other tactics to distract law enforcement.
With respect to the driver of the SUV gripping the steering wheel tightly, appearing
stiff, and looking straight ahead and not at Agent Sartin as he was driving beside the SUV,
the Ninth Circuit has held that reasonable suspicion that is based on eye contact or lack
thereof is highly subjective and can devolve into a case of “damned if you do, equally
damned if you don’t.” United States v. Montero-Camargo, 208 F.3d 1122, 1136 (9th Cir.
2000). As a result, that court has noted that this factor is “of questionable value . . .
generally.” Montero-Camargo, 208 F.3d at 1136. That is the case here because it makes
sense that the driver of the SUV was “white-knuckled” and focused on the road ahead given
the safety concern presented by Agent Sartin driving beside her in the opposing lane of
traffic on a two-lane highway. Moreover, as the Ninth Circuit has commented, there is no
doubt that if the driver of the SUV had looked at Agent Sartin, either through the rearview
and/or side mirrors or through the window when he was driving beside her vehicle, she
would have been “damned if she did” because that would have also been suspicious driving
behavior.
Additionally, it is human nature for a person who is not engaged in criminal activity
to exhibit signs of nervousness when a law enforcement officer appears to be following
them. As discussed above, the driver is concerned about committing a traffic infraction
that could lead to a vehicle stop; and that is especially true when a law enforcement officer
follows a vehicle for ten miles. In fact, Agent Sartin testified that drivers are “usually
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nervous when I pull alongside of them, especially if they’re engaged in something illicit.”
(Id. at 20.) Agent Sartin’s use of the qualifier “especially” shows (or at least implies) that
his experience is that most drivers are nervous when he pulls his Border Patrol vehicle
alongside of their vehicle even if the driver is not engaged in something illicit.
Finally, there is no basis for Agent Sartin’s assumption that the driver of the SUV
should have been relaxed because she had been driving many miles for many hours. He
did not know where she came from or how long she had been driving.
C. Usual traffic patterns
Both agents testified that traffic on Highway 80 is light, especially on a Saturday.
The light traffic likely led to Agent Sartin’s hunch that the SUV and sedan were engaged
in alien smuggling. Stated another way, he concluded that there was no reason for a vehicle
from California and a vehicle from Tucson to be travelling on Highway 80 early Saturday
morning. However, in drawing that conclusion, Agent Sartin assumed that the vehicles
were headed to California and Tucson and should have stayed on Interstate 10 and not gone
southwest on Highway 80. There is no basis for those assumptions.
D. The TECS Hit
Agent Myers was advised by Border Patrol dispatch that a TECS inquiry revealed
that the Chrysler had crossed into the United States through the Nogales Port of Entry
earlier in the day and then passed through the Border Patrol checkpoint on Interstate 19.
Agent Myers testified on direct examination that he found it suspicious that the Chrysler
came through the Nogales Port of Entry, travelled north on Interstate 19, and then ended
up travelling southwest on Highway 80. When asked by the Court to explain why that
information was suspicious, Agent Myers testified that “there’s no reason that a vehicle, if
their destination was Douglas, would need to go all the way up to I-10 and then take it all
the way over to Road Forks and then down to SR 80 east,” because there are multiple ways
to get to Douglas before SR 80. (Hr’g Tr. 11/3/25 at 78.)
After being provided with the TECS report, Agent Myers conceded that Border
Patrol dispatch provided him with the wrong date that the Chrysler crossed into the United
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States through the Nogales Port of Entry and passed through the immigration checkpoint
on Interstate 19. The TECS report shows that the correct date is January 30, 2025, and not
February 1, 2025, the date of the stop.3 Even if the Chrysler had crossed into the United
States on February 1, 2025, and travelled north on Interstate 19, Agent Myers makes
assumptions about the Chrysler’s destination and route of travel. He first assumes that the
Chrysler’s destination was Douglas, Arizona. He also assumes that because the Chrysler
went through the Interstate 19 checkpoint, it must have traveled north on Interstate 19 to
Interstate 10 and then took that road east to Highway 80. There is no basis for either
assumption.
E. The proximity to the border, the characteristics of the area where the
vehicles were encountered, previous experience with alien smuggling
traffic in the area, and recent illegal entrant activity.
There is no doubt that Agent Sartin first encountered the SUV and Chrysler
relatively close to the United-States-Mexico border in a remote area where Border Patrol
agents routinely see illegal alien traffic – i.e., about 30 miles from the border town of
Douglas, Arizona. In fact, both agents were told at muster about a group of three to five
suspected illegal aliens that had not been apprehended. It is arguable that any remote area
south of Tucson is an area where Border Patrol agents see illegal alien traffic. For example,
the Border Patrol’s area of responsibility for the Douglas sector is over a thousand square
miles. The same is presumably true for the Border Patrol’s other areas of responsibility.
That said, these factors still weigh in favor of the government in the reasonable suspicion
analysis. But these factors do not amount to reasonable suspicion given the other factors
discussed above.
3 The Court notes that government counsel did not argue that Agent Myers was
entitled to rely on this mistake of fact. Rather, government counsel argued that “there is
ultimately a discrepancy with regard to the dates [Agent Myers] believed he overheard and
what the dates were actually reported in the system However, even taking that into account,
the travel pattern for this Chrysler300 is very unusual and something that goes into their
analysis of whether or not they had reasonable suspicion to conduct a traffic stop of not
only the Pontiac, but also of the black Chrysler 300.” (Hr’g. Tr. 11/3/25 at 89, Doc. 75.).
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IV. RECOMMENDATION
For the foregoing reasons, the Magistrate Judge recommends that the District Judge
grant the Defendant’s Motion to Suppress for Lack of Reasonable Suspicion (Doc. 50).
Pursuant to 28 U.S.C. §636(b) and Rule 59(b)(2) of the Federal Rules of Criminal
Procedure, any party may serve and file written objections within fourteen (14) days after
being served with a copy of this Report and Recommendation. No reply shall be filed
unless leave is granted from the District Court. If objections are filed, the parties should
use the following case number: CR-25-01233-TUC-AMM..
Failure to file timely objections to any factual or legal determination of the
Magistrate Judge in accordance with Fed. R. Crim. P. 59 may result in waiver of the right
of review.
Dated this 9th day of December, 2025.
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