United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT

                              __________________

                                  No. 11-3677
                              __________________

United States of America,               *
                                        *
            Appellee,                   *
                                        *   Appeal from the United
      v.                                *   States District Court for the
                                        *   Southern District of Iowa.
Jorge Zamora-Lopez, also                *
known as Jorge Luis Zamora,             *
                                        *
            Appellant.                  *

                                  ___________

                             Submitted: May 18, 2012
                                Filed: July 24, 2012
                                 ___________

Before RILEY, Chief Judge, BYE and MELLOY, Circuit Judges.
                               ___________

RILEY, Chief Judge.

      Jorge Zamora-Lopez conditionally pled guilty to conspiracy to distribute 500
grams or more of a mixture containing methamphetamine, in violation of 21 U.S.C.
§§ 841(b)(1)(A) and 846. The district court1 sentenced him to 108 months



      1
       The Honorable John A. Jarvey, United States District Judge for the Southern
District of Iowa.
imprisonment. Zamora-Lopez appeals the district court’s denial of his motion to
suppress evidence obtained as a result of a warrantless traffic stop. We affirm.

I.     BACKGROUND
       A.     Facts
       In February 2011, a confidential informant provided Special Agent Michael
Mittan of the Iowa Division of Narcotics Enforcement with information leading to the
arrest of a methamphetamine supplier. The supplier agreed to cooperate with Agent
Mittan.

       The supplier informed Agent Mittan that he had purchased methamphetamine
from a man the supplier knew as “Nemo” (actually the Spanish nickname “Memo”)
every three to five days for approximately three years. These transactions usually
followed a specific pattern. The supplier or Memo would initiate a meeting with a
cell phone call. The supplier would drive to the intersection of South 37th Street and
Q Street in Omaha, Nebraska, and wait for Memo. Shortly thereafter, a vehicle
(sometimes a silver sport utility vehicle (SUV)) would pull behind the supplier’s
vehicle. Memo would exit from the passenger side of this vehicle and get into the
supplier’s vehicle. Both vehicles would then drive away, in different directions. The
supplier and Memo would complete the drug transaction while the supplier drove
around a nearby residential neighborhood. The supplier would then drive Memo back
to their meeting point area, and Memo would either be picked up by the other vehicle,
or would leave on foot. The supplier knew nothing about the individual who drove
Memo to and from these transactions, or even if the driver were the same person
every time.

      Agent Mittan decided to set up a controlled drug transaction between the
supplier and Memo for February 25, 2011. Agent Mittan organized a meeting to plan
the operation with the supplier, Douglas County (Nebraska) Deputy Sheriff Jason
Mass, and other law enforcement personnel. During this meeting, Memo twice called

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the supplier to set up a deal, and the supplier agreed. Officers established
surveillance near the designated point, and the supplier waited at the meeting point
as usual. A silver Jeep Cherokee pulled behind the supplier’s vehicle, and Deputy
Mass observed a man matching Memo’s description exit the passenger side of the
Jeep and enter the passenger’s side of the supplier’s vehicle. The two vehicles drove
away separately. Deputy Mass followed the Jeep in his unmarked vehicle.

       After following the Jeep for a few blocks, Deputy Mass decided to stop the
vehicle and arrest the driver. A marked K-9 sheriff’s vehicle signaled for the Jeep to
stop, and deputies approached the vehicle. The deputies ordered the driver, later
identified as Zamora-Lopez, to exit the vehicle. The deputies informed Zamora-
Lopez he was under arrest and placed him in handcuffs. When his arms were placed
behind his back, Zamora-Lopez’s coat pocket came open, revealing what Deputy
Mass believed to be a large baggie containing methamphetamine. The deputies
seized the baggie.

       B.     Procedural History
       A grand jury indicted Zamora-Lopez for conspiring to distribute
methamphetamine and for an immigration violation. Zamora-Lopez moved to
suppress the evidence uncovered as a result of the traffic stop. After a hearing, the
district court denied the motion because “[t]here was probable cause to believe that
the silver Jeep Cherokee and its driver had recently been involved in the trafficking
of approximately one-quarter pound of methamphetamine.” Zamora-Lopez pled
guilty to conspiracy to distribute methamphetamine, preserving his right to appeal the
district court’s suppression order. Zamora-Lopez appeals.

II.   DISCUSSION
      When reviewing the denial of a motion to suppress, we review questions of law
de novo and the district court’s factual findings for clear error. See United States v.
Payne, 

, 950 (8th Cir. 2008). We will affirm the district court “unless

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the denial of the motion ‘is unsupported by substantial evidence, based on an
erroneous interpretation of the law, or, based on the entire record, it is clear that a
mistake was made.’” Id. at 951 (quoting United States v. Stachowiak, 

,
854 (8th Cir. 2008)).

       The Fourth Amendment to the United States Constitution protects individuals
against unreasonable searches and seizures by the government. See U.S. Const.
amend. IV. Subject to a few narrow exceptions, a warrantless search or seizure
violates the Fourth Amendment. See Katz v. United States, 

, 357
(1967). “[W]here a police officer observes unusual conduct which leads him
reasonably to conclude in light of his experience that criminal activity may be afoot,
the officer may briefly stop the suspicious person and make reasonable inquiries
aimed at confirming or dispelling his suspicions.” Minnesota v. Dickerson, 

, 372-73 (1993) (quoting Terry v. Ohio, 

, 30 (1968)) (internal marks
omitted).2 Whether such suspicions are reasonable is assessed from the point of view
of trained law enforcement officers based on the totality of the circumstances known
to the officers at the relevant time. See United States v. Stewart, 

, 457
(8th Cir. 2011). If reasonable suspicion exists, officers may briefly detain a vehicle
and its occupants to conduct a reasonable investigation. See United States v. Jones,

, 924 (8th Cir. 2001) (confirming that an investigatory traffic stop is
“governed by the principles of Terry v. Ohio”).

      Zamora-Lopez argues the deputies lacked reasonable suspicion that the
unknown driver of the Jeep was involved in Memo’s narcotics trafficking operations.
This argument relies on a too-narrow conception of reasonable suspicion and fails to

      2
        On appeal, Zamora-Lopez only argues the deputies lacked reasonable
suspicion to conduct an investigatory stop. We do not consider whether other aspects
of the stop implicate constitutional concerns. See United States v. Kirk, 

, 1104 n.2 (8th Cir. 2008) (explaining the court of appeals will not consider
undeveloped issues perfunctorily raised in the appellate brief).

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consider the totality of the information available to the deputies. See Stewart, 631
F.3d at 457. The supplier earlier described to law enforcement a very specific pattern
of long-standing conduct that nearly always involved three people—the supplier,
Memo, and an unknown driver. Memo and his driver sometimes arrived in a silver
SUV. Memo’s driver frequently stayed in the area to pick up Memo following the
drug transaction. The deputies’ surveillance observations during the controlled buy
confirmed the supplier’s account in virtually every detail. Cf. Illinois v. Gates, 

, 241-46 (1983) (concluding probable cause existed to issue a search warrant
where an anonymous informant’s tip was corroborated by law enforcement officers’
independent investigations).

       The deputies believed Memo was an experienced and high-volume drug
trafficker. Such an individual might be expected to rely on trusted confederates to
drive him to and from his drug transactions. While Memo might have used unknown
and innocent drivers, it was reasonable for the deputies to suspect the unidentified
driver was knowingly involved in Memo’s drug trafficking activities. Thus, Zamora-
Lopez’s Fourth Amendment rights were not violated, and the district court’s
admission of the evidence resulting from the traffic stop was proper.

III.   CONCLUSION
       We affirm.
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