United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
                                  ___________

                                  No. 03-2445
                                  ___________

United States of America,            *
                                     *
           Plaintiff-Appellee,       *
                                     * Appeal from the United States
      v.                             * District Court for the
                                     * Eastern District of Missouri.
Orlando Martinez,                    *
                                     *
           Defendant-Appellant.      *
                                ___________

                             Submitted: January 13, 2004

                                 Filed: March 2, 2004
                                  ___________

Before BYE, LAY, and SMITH, Circuit Judges.
                             ___________

LAY, Circuit Judge.

       A jury found Orlando Martinez guilty of possession with intent to distribute
over five kilograms of cocaine. Martinez appeals from the judgment of conviction,
arguing the district court1 erred in denying his motion to suppress evidence and in
admitting certain evidence at trial. We affirm.




      1
       The Honorable Jean C. Hamilton, United States District Judge for the Eastern
District of Missouri.
                                           I.

       On June 30, 2002, officers from the Phelps County, Missouri, Sheriff’s
Department participated in a drug interdiction program on Interstate 44 in Phelps
County. As part of the program, the officers placed signs reading “Drug Enforcement
Checkpoint Ahead, One Fourth Mile” and “Drug Dogs In Use” along the eastbound
lanes of Interstate 44. The signs, written in English and Spanish, were located just
west of the exit for Sugar Tree Road on a portion of Interstate 44 that curves sharply
so drivers cannot see what is ahead. The Sugar Tree Road exit is located in a remote
area that has no shops or restaurants. There is little reason for motorists to take the
Sugar Tree Road exit unless they are local residents.

       In reality, there was no drug enforcement checkpoint on Interstate 44. Instead,
the signs placed along Interstate 44 were a ruse to induce motorists engaged in drug-
related activity to take the Sugar Tree Road exit. Officers were stationed at the top
of the Sugar Tree Road exit but did not stop every vehicle taking the exit. Only
motorists who were observed committing a traffic violation were stopped.

       At about 2:00 p.m. on June 30, 2002, Martinez was traveling eastbound on
Interstate 44 in his tractor trailer. Deputy David Rightnowar and Sheriff Don
Blankenship, who were stationed in separate vehicles at the top of the Sugar Tree
Road exit, observed Martinez’s tractor trailer come up the exit ramp, roll through the
stop sign at the top of the exit ramp, turn left across the overpass, and then turn left
again onto the entrance ramp to westbound Interstate 44. Upon observing the traffic
violation, Deputy Rightnowar followed Martinez and stopped him on the shoulder of
westbound Interstate 44. Sheriff Blankenship arrived on the scene a minute or so
after Deputy Rightnowar’s stop.

      Deputy Rightnowar asked Martinez about the nature of his travel and why he
had turned around at the Sugar Tree Road exit. Martinez said he was traveling from

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California to Maine and had turned around to go back to the last exit to eat. Deputy
Rightnowar found Martinez’s answer suspicious because he knew there were no
restaurants at the last exit and that the closest restaurant was three exits back. Both
Deputy Rightnowar and Sheriff Blankenship observed that Martinez was extremely
nervous and that his hands were shaking uncontrollably. Deputy Rightnowar asked
Martinez if he had anything in the truck, and Martinez answered “no.” When Deputy
Rightnowar asked if he could search the truck, Martinez answered “yes” and handed
him the keys to the trailer.

       At about this time, other officers arrived at the scene with a drug detection dog.
After Martinez had consented to the search of the truck, the drug dog was allowed to
sniff the tractor trailer and reacted in a manner indicating the presence of drugs.
Within a few minutes, the officers found seventeen kilograms of cocaine and a small
amount of crack cocaine stuffed in a duffle bag in the trailer of the truck. Martinez
was then arrested and read his Miranda rights.

       Prior to trial, Martinez moved to suppress evidence of the drugs, arguing, in
part, that he was seized and his truck was searched in violation of his Fourth
Amendment rights. On October 18, 2002, the magistrate judge2 issued a Report and
Recommendation, recommending that the motion be denied. Martinez objected to the
Report and Recommendation and asked the district court to refer the matter back to
the magistrate judge for reconsideration in light of United States v. Yousif, 

(8th Cir. 2002).

       Yousif involved a “ruse checkpoint” at the Sugar Tree Road exit. As in this
case, the Phelps County Sheriff’s Department placed signs along eastbound Interstate
44 near the Sugar Tree Road exit indicating that a drug checkpoint was ahead, but


      2
       The Honorable Frederick R. Buckles, United States Magistrate Judge for the
Eastern District of Missouri.

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there was no checkpoint along the Interstate. 

Instead, the checkpoint was
located on the Sugar Tree Road exit ramp. 

held that the Sugar Tree
Road checkpoint, as it was conducted at that time, “violated the Fourth Amendment
insofar as its primary purpose was the interdiction of drug trafficking . . . and the
officers operating the Sugar Tree Road checkpoint were under instructions to stop
every vehicle that took the Sugar Tree Road exit.” 

We also held that the
totality of the circumstances did not justify the stop since many of the circumstances
would never have arisen absent the illegal checkpoint, 

and that Yousif’s
allegedly voluntary consent to the search “did not purge the primary taint of the
illegal stop.” 

       Rather than referring the matter back to the magistrate judge, the district court
analyzed Yousif and found it to be distinguishable because Martinez’s traffic
violation provided a legitimate reason to detain Martinez, Martinez’s suspicious
behavior upon being stopped justified his further detention, and Martinez’s consent
to the search of his vehicle was voluntarily. On this basis, the district court adopted
the magistrate judge’s Report and Recommendation and denied the motion to
suppress. Following a jury trial, Martinez was convicted and sentenced to 151
months imprisonment. He now appeals.

                                          II.

       We first address Martinez’s claim that the district court erred in denying the
motion to suppress. The denial of a motion to suppress is reviewed de novo, but the
district court’s underlying factual determinations are reviewed for clear error. See
United States v. Walker, 

, 1036 (8th Cir. 2003).

       All of Martinez’s arguments on this issue more or less hinge on his assertion
that the officers were operating an illegal checkpoint, which rendered the seizure of
his truck and subsequent search of the vehicle unconstitutional under the rationale of

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City of Indianapolis v. Edmond, 

(2000), and Yousif. The problem with
Martinez’s arguments is that the officers in this case were not operating a checkpoint
like those in Edmond and Yousif.

       The checkpoints in Edmond involved the use of signs similar to the ones used
in the present case and were intended to interdict illegal 

.
However, unlike the present case, the police in Edmond stopped a predetermined
number of vehicles at each checkpoint. 

The primary purpose of the
checkpoints in Edmond was to “uncover evidence of ordinary criminal wrongdoing.”

In holding that the checkpoints violated the Fourth Amendment, the
Court explained:

      The primary purpose of the Indianapolis narcotics checkpoints is in the
      end to advance “the general interest in crime control[.]” We decline to
      suspend the usual requirement of individualized suspicion where the
      police seek to employ a checkpoint primarily for the ordinary enterprise
      of investigating crimes. We cannot sanction stops justified only by the
      generalized and ever-present possibility that interrogation and inspection
      may reveal that any given motorist has committed some crime.

(citation omitted).

       While the present case is factually similar to Edmond and Yousif, a critical
distinction remains: Edmond and Yousif involved the use of actual checkpoints at
which motorists were stopped regardless of whether they had committed a traffic
violation. Here, there was no checkpoint on the Sugar Tree Road exit, and motorists
who took the exit were not stopped unless they were observed committing a traffic
violation. Given this distinction, Edmond and Yousif are not controlling.3

      3
        Martinez’s arguments that (1) his traffic violation cannot be considered a valid
basis for the stop because it was the direct result of an illegal checkpoint, and (2) the
drugs are inadmissible because they were the indirect result of an illegal checkpoint,

                                          -5-
Nonetheless, we still must address whether Martinez’s Fourth Amendment rights
were violated. For the reasons that follow, we conclude they were not.

      A traffic stop constitutes a “seizure” within the meaning of the Fourth
Amendment, see Delaware v. Prouse, 

, 653 (1979), and therefore must
be reasonable to survive constitutional scrutiny. See Whren v. United States, 

, 810 (1996). A traffic stop based on probable cause is reasonable under the
Fourth Amendment. See 

It is well settled that “[a]ny traffic violation,
however minor, provides probable cause for a traffic stop.” United States v. Johnson,

, 357 (8th Cir. 1995) (quoting United States v. Bloomfield, 

,
915 (8th Cir. 1994).

        There is no dispute that Martinez committed a traffic violation by failing to
stop at the stop sign. As a result, the officers had probable cause to stop Martinez.
The fact that the officers may have believed Martinez was carrying illegal drugs does
not invalidate an otherwise valid stop. See 

(holding that
traffic stops based on probable cause are valid even if the officer stopping the vehicle
suspects that the occupant is engaged in other illegal activity). Furthermore, the
officers’ use of the deceptive signs does not make the stop illegal, as it is well-
established that officers may use deception to uncover criminal behavior. See, e.g.,
Sorrells v. United States, 

, 441 (1932). Thus, we find no error in the
district court’s finding that Martinez was lawfully stopped after committing a traffic
violation.

      Martinez also argues his consent to the search of the vehicle was involuntary
and did not purge the taint resulting from the use of the illegal checkpoint. We need
not address the second part of Martinez’s argument because there was no illegal
checkpoint in this case. We therefore review whether the district court clearly erred


are foreclosed by our conclusion that there was no illegal checkpoint in this case.

                                          -6-
in finding that Martinez’s consent was voluntary. See United States v. Chaidez, 

, 380 (8th Cir. 1990).

       The magistrate judge found that Martinez was not under the influence of
alcohol or drugs at the time of the encounter, was not threatened or physically abused
during the encounter, and was not under arrest at the time he gave consent. See 

(setting forth factors for determining the voluntariness of a consent to search).
The magistrate judge further found that the encounter took place in an open and
public area, that the officers made no promises to Martinez to induce his consent, and
that Martinez, who is of Hispanic origin, spoke English in a coherent and responsive
manner. See 

court adopted the magistrate judge’s findings, and we
believe there is substantial evidence in the record to support the district court’s
decision. On this basis, we conclude the district court’s finding that Martinez’s
consent to the search was given voluntarily is not clearly erroneous.

                                          III.

       Martinez argues the district court erred in admitting expert testimony regarding
the structure and operation of drug trafficking organizations. During Martinez’s trial,
Salvator Cira, an Intelligence Research Specialist at the Department of Justice with
thirty years of law-enforcement experience, testified for the Government about,
among other things, the structure of drug trafficking organizations and the role of
drug couriers. Cira testified that a drug distributor would not have allowed the
quantity of drugs in this case out of his control, and that, in his experience, he had
never encountered a courier who did not know what was in his vehicle. Martinez
never objected to the admission of Cira’s testimony in district court. Therefore, we
review this claim for plain error. See United States v. Jones, 

, 814 (8th
Cir. 2001).




                                          -7-
      Relying on Ninth Circuit precedent, Martinez contends admission of the
testimony was error because he was not charged with conspiracy to import drugs and
no evidence was presented to link him to an actual drug trafficking organization. See
United States v. Vallejo, 

, 1012 (9th Cir. 2001) (holding that expert
testimony concerning the structure of drug trafficking organizations is inadmissible
where the defendant is not charged with a conspiracy to import drugs or where such
evidence is not otherwise probative of a matter properly before the court). Martinez
also contends admission of the testimony was clearly prejudicial to him because it
portrayed him as a member of a large drug organization. See United States v. Pineda-
Torres, 

, 866 (9th Cir. 2002) (holding that the district court committed
prejudicial error in admitting expert testimony about the structure of drug trafficking
organizations because the testimony portrayed the defendant as a member of such an
organization and implied the defendant knew the drugs were in his vehicle). We are
not persuaded by Martinez’s arguments.

      We conclude the district court did not plainly err in admitting the expert
testimony because the testimony was relevant to show knowledge, and the probative
value of the testimony was not substantially outweighed by any danger of unfair
prejudice. See Fed. R. Evid. 401 and 403. Martinez maintained at trial that the
Government failed to present evidence that he knew the drugs were on his truck or
that he had placed the drugs on his truck. In effect, Martinez relied on an
“unknowing courier” defense. This court has approved the admission of expert
testimony to the effect that “drug traffickers do not typically use couriers who are
unaware they are transporting drugs” where one theory of defense was that the
defendant was unaware the drugs were present. United States v. Vasquez, 

, 427 (8th Cir. 2000).4 Furthermore, we have consistently held that it is within the

      4
       The Ninth Circuit has also approved the use of such testimony. See United
States v. Murillo, 

, 1176-78 (9th Cir. 2001) (upholding the admission
of expert testimony that drug traffickers do not routinely entrust large quantities of
drugs to unknowing couriers to attack defendant’s unknowing courier defense).

                                         -8-
discretion of the trial court to allow expert testimony concerning “the modus operandi
of drug dealers in areas concerning activities which are not something with which
most jurors are familiar.” United States v. Solorio-Tafolla, 

, 966 (8th
Cir. 2003) (quoting United States v. Molina, 

, 1056 (8th Cir. 1999)).

                                         IV.

      Because we find no error in the district court’s denial of the motion to suppress
or admission of evidence, we affirm.
                      ______________________________




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