United States of America v. Aaron Cardinale

United States Court of Appeals
For the Eighth Circuit
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No. 24-2784
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United States of America
Plaintiff - Appellee
v.
Aaron Cardinale
Defendant - Appellant
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Appeal from United States District Court
for the District of Nebraska - Omaha
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Submitted: May 16, 2025
Filed: August 4, 2025
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Before COLLOTON, Chief Judge, SMITH and SHEPHERD, Circuit Judges.
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SMITH, Circuit Judge.
Aaron Cardinale entered a conditional guilty plea under Federal Rule of
Criminal Procedure 11(a)(2) after the district court1 denied his motion to suppress
evidence recovered from a traffic stop. He now appeals that denial, arguing that the
1 The Honorable Robert F. Rossiter Jr., Chief Judge, United States District
Court for the District of Nebraska.

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district court erred in determining that the officer was reasonable in his belief that
the stop was justified. We affirm.
I. Background
Early in the morning on July 27, 2022, Omaha Police Officers Daniel
Cleveland and Jared Freyermuth were on patrol in Omaha, Nebraska. The officers
saw a Chevrolet Malibu at a nearby gas station and decided to investigate. They
discovered that it was registered to Linda Loury, who had a history of
methamphetamine use and a suspended license. They observed a man, later
determined to be Cardinale, get into the driver’s seat and a woman get into the
passenger seat. The officers followed them as they left the gas station.
After leaving the gas station, Cardinale began driving on Deer Park
Boulevard. Cardinale activated his left turn signal and made a left turn onto 15th
Street. According to the officers, they observed Cardinale fail to signal for the left
turn more than 100 feet in advance of the turn as required by Nebraska law. See Neb.
Rev. Stat. § 60-6,161(2). They stopped him. During the stop, the officers had a K-9
dog conduct a sniff of the car. The dog alerted to drugs, and the officers arrested
Cardinale.
Cardinale was subsequently indicted with one count of possession with intent
to distribute more than 50 grams of actual methamphetamine, in violation of 21
U.S.C. § 841(a)(1) and (b)(1). Cardinale moved to suppress the evidence against
him. Relevant to this appeal, he contends that the officers stopped the vehicle without
reasonable suspicion. At the suppression hearing, the magistrate judge recounted the
officers’ testimony as follows:
Officer Cleveland stated that as the officers were following the Malibu,
he noticed it increase[d] speed as it approached 15th Street, while it was
still westbound on Deer Park Boulevard. Officer Cleveland testified he
did not know the Malibu’s intended destination, but that the Malibu’s
acceleration was consistent with an attempt to evade police.

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Officer Cleveland testified that while it was still westbound on
Deer Park Boulevard, the Malibu’s turn signal activated, and the
Malibu immediately made a left turn onto 15th Street. Officer
Cleveland testified he did not know how much distance was between
the cruiser and the Malibu as the Malibu turned left onto 15th Street.
The cruiser camera shows that it took the cruiser about 20 seconds to
go down Deer Park Boulevard and turn left. Officer Cleveland also
testified he does not know how much distance is between 13th and 14th
Streets, or how much distance is between 14th and 15th Streets. Officer
Cleveland stated that based on his training and experience, as well as
years of working accidents, and general speed estimation and time, the
signal activated less than 100 feet before the turn onto 15th Street,
which is a violation of Nebraska law. . . . Officer Cleveland testified
[that] the officers then activated the cruiser’s overhead lights to notify
the occupants of the Malibu that the officers were conducting a traffic
stop.
R. Doc. 74, at 3 (citations omitted).
The magistrate judge recommended that the motion be denied, and the district
court agreed with its recommendation that a reasonable officer could have believed
that Cardinale did not signal at least 100 feet or more before he turned onto 15th
Street. The court relied primarily on Officer Cleveland’s testimony that he saw
Cardinale activate his signal “[j]ust prior to making the turn onto 15th Street, . . .
which was not prior to 100 feet” before Cardinale executed the turn as required by
Nebraska law. R. Doc. 73, at 8. The district court also reviewed the police video
evidence and Cardinale’s other exhibits, including maps and mathematical
equations. It determined that the evidence did not clearly show that Officer
Cleveland’s belief that Cardinale failed to signal properly was objectively
unreasonable. The district court considered Cardinale’s suggested standard for
officers’ judgment in such matters to be unreasonable. It would “assume officers
could make the sophisticated, mathematical calculations . . . while patrolling in a
moving cruiser.” R. Doc. 76, at 6.

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Cardinale filed a motion to reconsider the district court’s order, urging the
court to resolve the evidentiary dispute allegedly shown by his exhibits. He argued
that the district court cut short any analysis of the government’s evidence by simply
relying on Officer Cleveland’s testimony. The district court denied the motion,
responding that it based its conclusion on “the entire record, including Officer
Cleveland’s testimony, the video footage, and Cardinale’s exhibits, in concluding
that a ‘reasonable officer, confronted with the facts known to the officer at the time
of the stop, could have believed that there was a fair probability that a violation of
law had occurred.’” R. Doc. 82, at 4 (quoting United States v. Rederick, 65 F.4th
961, 965 (8th Cir. 2023)). Cardinale argued that Officer Cleveland’s testimony failed
to provide the requisite “historical facts” that could add up to probable cause to
support the government’s burden. Id. at 5 (quoting Ornelas v. United States, 517
U.S. 690, 696 (1996)). The district court stated that the dash camera footage provided
relative context “of the contemporaneous events and vantage point through which a
reasonable officer would have perceived the incident.” Id. Cardinale also argued that
the district court failed to consider his mathematical equations that showed the
“reality” needed to assess the reasonableness of the stop. Id. The district court
responded by noting that those arguments had been considered, but the “pinpoint
scientific accuracy of [Cardinale’s] calculations was [not] clearly deducible from the
footage nor necessary to making a well-founded probable cause conclusion in the
context of this case.” Id. (citing Heien v. North Carolina, 574 U.S. 54, 60–61 (2014)
(stating that reasonableness does not require perfection and that the Fourth
Amendment tolerates officers’ reasonable mistakes of fact); New v. Denver, 787
F.3d 895, 900–01 (8th Cir. 2015) (concluding that “hindsight evidence” was
irrelevant to probable cause analysis)). Denied reconsideration, Cardinale then
entered a conditional guilty plea enabling this appeal of the denial of his motion to
suppress.
II. Discussion
On appeal, Cardinale argues that the government did not present sufficient
historical facts to conclude that the traffic stop was reasonable. He avers that Officer

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Cleveland’s testimony was too conclusory to establish the reasonableness of the
stop.
“In evaluating the denial of a motion to suppress, we review the district court’s
legal conclusions de novo and factual findings for clear error.” United States v. Milk,
66 F.4th 1121, 1130 (8th Cir. 2023) (quoting United States v. Nyah, 35 F.4th 1100,
1105 (8th Cir. 2022)). We will affirm the district court’s denial of the motion unless
it “is unsupported by substantial evidence, is based on an erroneous interpretation of
the law, or it is clear, based on the entire record, that a mistake was made.” Id.
(quoting United States v. Walker, 840 F.3d 477, 483 (8th Cir. 2016)).
“Under the Fourth Amendment, a traffic stop is reasonable if it is supported
by either probable cause or an articulable and reasonable suspicion that a traffic
violation has occurred.” United States v. Holly, 983 F.3d 361, 364 (8th Cir. 2020)
(quoting United States v. Washington, 455 F.3d 824, 826 (8th Cir. 2006)). “Any
traffic violation, however minor, provides probable cause for a traffic stop.” United
States v. Hollins, 685 F.3d 703, 706 (8th Cir. 2012) (quoting United States v. Wright,
512 F.3d 466, 471 (8th Cir. 2008)). “[T]he concept of reasonable suspicion is
composed of ‘commonsense’ and ‘nontechnical’ concepts instead of ‘finely-tuned
standards,’ and determining whether there is reasonable suspicion depends on ‘“the
factual and practical considerations of everyday life on which reasonable and
prudent men, not legal technicians, act.”’” United States v. Dillard, 825 F.3d 472,
474–75 (8th Cir. 2016) (quoting Ornelas, 517 U.S. at 695–96).
Cardinale principally relies on United States v. Alvarado-Zarza, 782 F.3d 246
(5th Cir. 2015). There, a Texas officer pulled over a driver for failing to activate his
turn signal at least 100 feet in advance of his turn, in violation of Texas law. Id. at
248. At the suppression hearing, the officer testified that the defendant did not signal
100 feet before turning and that the turn began when he switched lanes prior to the
turn, not when he actually turned left. Id. Texas law, however, differentiated between
a lane change and a turn and only required a signal 100 feet before a turn. Id. at 250.

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The officer’s failure to distinguish between a lane change and a turn was an
objectively unreasonable mistake of law per the Fifth Circuit in Alvarado-Zarza. Id.
The officer in Alvarado-Zarza also made a mistake of fact related to the
distance that the vehicle traveled after the defendant activated the turn signal. Id. at
251. The defendant’s expert witness had testified that the defendant activated his
turn signal “200 feet before changing lanes and 300 feet before turning.” Id. at 250.
The Fifth Circuit concluded that because “of his mistaken assumption about the
application of the 100–foot requirement,” taken together with his testimony that he
acted quickly and could not actually measure the signaling distance, his
testimony did not provide the sort of specific, articulable facts which
would allow a court to determine that he possessed a reasonable
suspicion that [the defendant] had committed a traffic violation. The
fact that the actual distance between the signal and the turn was
approximately 300 feet, and that [the officer] provided no explanation
as to why he might have thought the distance was less than 100 feet,
only reinforces this conclusion.
Id. at 251. Although similar, there are two key distinctions between this case and
Alvarado-Zarza. First, the defendant in Alvarado-Zarza had an expert witness testify
specifically as to the distance of the lane change, which was “plainly supported” by
the video, and the government there did not challenge those measurements. Id. Here,
on the other hand, the video did not provide a clear record, as the video was
“incredibly grainy and blurry” and of “very poor quality.” R. Doc. 73, at 39–40.
Furthermore, the government successfully disputed Cardinale’s attempt to introduce
distances based on a failure to provide a proper basis for the distances on maps that
he attempted to bring into evidence. The Alvarado-Zarza court found no objective
reasonable suspicion based on “[t]he fact that the actual distance between the signal
and the turn was approximately 300 feet.” 782 F.3d at 251. The actual distance is
unknown in this case. Cardinale did not clearly establish any exact distances.
Additionally, Officer Cleveland explained why he thought that a traffic violation had

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occurred: Cardinale turned “almost immediately” after activating his turn signal. R.
Doc. 73, at 46.
Several cases from this circuit provide helpful guidance. In Holly, officers
pulled over Holly after observing him run a stop sign. 983 F.3d at 363. Holly
disputed whether the officers could have seen him at the intersection given their
obscured vantage point. Id. Holly presented evidence from investigators that
allegedly showed that it would have been impossible for the officers to see him fail
to stop at the stop sign because of an obstruction in their view from their vantage
point on the road. Id. The officers, on the other hand, testified that they saw the
vehicle fail to stop at the stop sign just after Holly passed the obstruction. Id. The
court characterized their testimony as “[the officer] testified that based on his
training and experience and the speed of Holly on College and in the intersection,
he did not believe there was any way Holly stopped at the stop sign.” Id. The district
court credited the officers’ testimony over the defense investigator’s testimony. Id.
On appeal, this court held that the district court’s decision to credit the
officers’ account over the experts’ account was not clearly erroneous. Id. at 364.
“[T]here is no extrinsic evidence that clearly contradicts the officers’ account, nor
was the officers’ testimony ‘so internally inconsistent or implausible on its face that
a reasonable fact-finder would not credit it.’” Id. (quoting United States v. Heath, 58
F.3d 1271, 1275 (8th Cir. 1995)). Notably, Holly’s “experts admitted [that] they
were unable to recreate the exact circumstances of the events.” Id. Like in Holly,
there is no extrinsic evidence here that clearly refutes Officer Cleveland’s testimony
or is even inconsistent with that testimony. This record also lacks expert evidence
disputing Officer Cleveland’s testimony.
United States v. Houston, 548 F.3d 1151 (8th Cir. 2008), is also similar. There,
an officer traveling in a patrol car approached an intersection traveling southbound
when the traffic light turned green. Id. at 1152. As the light turned green, he could
see Houston still traveling westbound through the intersection. Id. The subsequent
stop resulted in an arrest for possession of cocaine, and Houston moved to suppress

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based on a lack of probable cause that a traffic violation had occurred. Id. at 1153.
Houston argued that the officer could not have ruled out possible hypothetical legal
reasons for him being in the intersection. Id. However, relying on just the officer’s
testimony, this court stated that “the district court found credible [the officer’s]
testimony that he saw Houston run a red light. . . . These findings were supported by
the record[,] and no evidence was introduced to the contrary.” Id.
The officers in Houston and Holly were not required to present the type of
evidence or show the understanding that Cardinale would require of Officer
Cleveland. Cardinale argues that Officer Cleveland testified that he did not know
various distances in the case, including the distance between his car and the Malibu
at several points, the distance between several different streets, the length of the road
in which Cardinale was driving before turning left, and different speeds of the
vehicles involved at certain times. Neither Houston or Holly required such
knowledge. Rather, in both cases, the officer relied on their experience and expertise
to determine whether a traffic violation had occurred.
“The existence of reasonable, articulable suspicion is determined by the
totality of the circumstances, taking into account an officer’s deductions and rational
inferences resulting from relevant training and experience.” United States v. Fields,
832 F.3d 831, 834 (8th Cir. 2016) (quoting United States v. Horton, 611 F.3d 936,
940 (8th Cir. 2010)). “[I]t is well established that mistakes of law or fact, if
objectively reasonable, may still justify a valid stop.” United States v. Rutledge, 61
F.4th 597, 602 (8th Cir. 2023) (alteration in original) (quoting United States v.
James, 52 F.4th 1035, 1038 (8th Cir. 2022)). “To be reasonable is not to be perfect,
and so the Fourth Amendment allows for some mistakes on the part of government
officials, giving them ‘fair leeway for enforcing the law in the community’s
protection.’” Holly, 983 F.3d at 364 (quoting Heien, 574 U.S. at 60–61). “Thus, even
if [Cardinale] was not technically in violation of the Nebraska statute, if Officer
[Cleveland] reasonably believed that [Cardinale] violated the statute, the stop was
valid.” United States v. Flores-Sandoval, 366 F.3d 961, 962 (8th Cir. 2004).

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Officer Cleveland testified that in his training and experience, Cardinale did
not activate his turn signal 100 feet prior to turning, as he turned “almost
immediately” after activating the signal. R. Doc. 73, at 46. The district court credited
this testimony. Officer Cleveland was not required to understand exact distances or
speeds in making his decision to stop the vehicle, as he was only required to be
reasonable, not perfect. See Heien, 574 U.S. at 60. None of the other evidence
contradicts his testimony, and we give “due weight to inferences drawn from those
facts by resident judges and local law enforcement officers.” Ornelas, 517 U.S. at
699. Thus, the district court did not clearly err in crediting Officer Cleveland’s
testimony and finding that he had reasonable suspicion that a traffic violation had
occurred.
III. Conclusion
Accordingly, we affirm the district court’s denial of Cardinale’s motion to
suppress evidence.
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