Drug-Dog Alert During an Ongoing Traffic Stop Establishes Automobile-Exception Probable Cause; Marijuana Odor and “Shake” Support Search and Arrest

1. Introduction

In United States v. Nicholas Smith (11th Cir. July 2, 2026) (per curiam) (unpublished), the Eleventh Circuit affirmed Nicholas P. Smith’s conviction for possession of fentanyl with intent to distribute, 21 U.S.C. § 841(a)(1), (b)(1)(C), after the district court denied his motion to suppress fentanyl discovered during a pat-down following a traffic stop.

The appeal presented three closely related Fourth Amendment questions: (1) whether officers had probable cause to initiate the traffic stop based on observed traffic violations; (2) whether they had probable cause to search the vehicle under the automobile exception; and (3) whether they had probable cause to arrest Smith (and thus to conduct a search incident to arrest / associated pat-down) based on marijuana-related indicators, including odor and “shake,” notwithstanding Florida’s medical marijuana regime.

2. Summary of the Opinion

The Eleventh Circuit affirmed across the board. It held:

  • The stop was supported by probable cause because officers observed Smith stop with tires in a crosswalk and proceed through an intersection on a red light, violating FLA. STAT. § 316.1945 and § 316.075(c)(1), consistent with United States v. Harris.
  • The vehicle search was valid under the automobile exception because the car was readily mobile and a drug-trained canine’s alert supplied probable cause, consistent with Pennsylvania v. Labron and United States v. Tamari.
  • The stop was not unlawfully prolonged: the canine was present from the start and the canine sniff occurred within the normal timeframe of the traffic stop, consistent with United States v. Campbell and Rodriguez v. United States.
  • Probable cause existed to search and arrest based on a combination of factors, including the recognizable smell of marijuana (still a probable-cause indicator in Eleventh Circuit precedent), Smith’s behavior, the canine alert, and visible marijuana “shake,” consistent with United States v. Lueck.

3. Analysis

3.1. Precedents Cited

A. Standards of review and deference to factfinding

  • United States v. Delancy and United States v. Smith frame suppression rulings as mixed questions: factual findings are reviewed for clear error, legal conclusions de novo.
  • The court emphasized how hard it is to overturn factual findings under clear-error review, relying on United States v. Isaac (quoting United States v. Rothenberg), OHI Asset (VA) Martinsville SNF, LLC v. Wagner (In re Wagner) (quoting Anderson v. City of Bessemer City), and Mach. Rental, Inc. v. Herpel (In re Multiponics, Inc.). This framing mattered because Smith’s attack on the traffic-stop basis largely contested what the officers observed.
  • United States v. Ramirez-Chilel (quoting United States v. Eddy) reinforced that appellate courts accept the district court’s fact version unless it is implausible on its face.
  • Bonner v. City of Prichard, Ala. was cited for the binding effect of former Fifth Circuit decisions—important later because the marijuana-odor rule draws heavily from Fifth Circuit precedent.

B. Legality of the traffic stop

  • Whren v. United States supplied the foundational rule that a traffic stop is a Fourth Amendment seizure, but is reasonable when supported by probable cause (or reasonable suspicion).
  • Terry v. Ohio, United States v. Harris, and United States v. Chanthasouxat supplied the Eleventh Circuit’s two-track justification for stops: probable cause of a traffic violation or Terry reasonable suspicion.
  • The court treated the observed crosswalk stop and red-light entry as straightforward traffic violations under Florida statutes and, under United States v. Harris, sufficient to justify the stop regardless of other asserted reasons (such as window tint).
  • United States v. Thomas was used to underscore that the court need not decide the tint issue if another offense supplies probable cause.

C. Probable cause and the automobile exception

  • United States v. Sokolow (quoting Illinois v. Gates) supplied the general definition of probable cause as a “fair probability” of finding contraband or evidence.
  • The vehicle search rested on the automobile exception as articulated in Pennsylvania v. Labron (citing California v. Carney): if a vehicle is readily mobile and probable cause exists, a warrant is not required.
  • The court treated a canine alert as a direct source of probable cause, relying on United States v. Tamari (quoting United States v. Banks), and citing United States v. Braddy.
  • The court also cited United States v. Watts for the general principle that warrantless searches are per se unreasonable unless an exception applies.

D. Duration of the stop and Rodriguez/Campbell limits

  • United States v. Campbell (en banc) (quoting Florida v. Royer) provided the governing limitation: traffic stops must be limited in scope and duration; officers cannot extend a stop to fish for probable cause.
  • Rodriguez v. United States supplied the key endpoint principle: authority for the stop ends when tasks tied to the traffic infraction are (or reasonably should have been) completed.
  • Applying those cases, the court found no unlawful extension because the canine was present from the beginning and the detection occurred quickly (the opinion notes about three and a half minutes once detection began).

E. Marijuana odor as a probable-cause factor, despite evolving state law

  • United States v. Lueck stated the Eleventh Circuit rule: “the recognizable smell of marijuana gives rise to probable cause supporting a warrantless search.”
  • United States v. Lueck itself relies on a line of former Fifth Circuit decisions—United States v. Rivera, United States v. Barnard, United States v. Diaz, and United States v. Coffey—which, via Bonner v. City of Prichard, Ala., remain authoritative.
  • The panel addressed (and rejected as underdeveloped/forfeited) Smith’s suggestion that “in the State of Florida” marijuana odor no longer supports probable cause, citing Cont'l Tech. Servs., Inc. v. Rockwell Int'l Corp. for the principle that merely invoking controlling law is not a developed argument.
  • The opinion’s footnote discussion of Florida’s medical marijuana structure cited Fla. Dep't of Health v. Florigrown, LLC, while also noting the continuing federal illegality of marijuana with United States v. Trevino.

F. Issue preservation and reply-brief limitations (certification request)

  • The court declined Smith’s late request (raised only in his reply brief) to certify a Florida statutory question to the Florida Supreme Court, applying United States v. Chalker, Lovett v. Ray, and United States v. Levy.
  • United States v. Campbell (en banc) was cited again for the court’s reluctance to reach forfeited issues.
  • A separate footnote referenced United States v. Florida for the principle that the court generally will not raise unpresented issues sua sponte.

3.2. Legal Reasoning

A. Stop: probable cause is satisfied by observed traffic violations

The court’s reasoning began with a practical Fourth Amendment premise: if officers observe conduct that violates traffic laws, they have probable cause to stop the vehicle. The district court found that Smith (1) stopped with tires in the crosswalk and (2) proceeded through the intersection on a steady red. On appeal, Smith attempted to re-characterize the driving as “cautious” and compliant, but the Eleventh Circuit treated this as an attack on factfinding. Under the highly deferential clear-error standard (as elaborated in In re Wagner and Anderson v. City of Bessemer City), the panel held Smith had not shown the district court’s findings were mistaken.

A key structural point: because the crosswalk/red-light violations supplied probable cause, the panel expressly avoided deciding whether window tint could also justify the stop (United States v. Thomas), reinforcing the principle that one valid ground is enough.

B. Search: the canine alert triggered the automobile exception, and timing mattered

The court then separated two questions that are often conflated: whether officers ultimately had probable cause to search the car, and whether they unlawfully extended the stop to generate that cause. On the first question, United States v. Tamari supplied a bright, administrable rule: a drug-trained canine’s alert establishes probable cause. Combined with the vehicle’s ready mobility (Pennsylvania v. Labron), that probable cause activated the automobile exception and made a warrant unnecessary.

On the second question—duration—the panel applied United States v. Campbell and Rodriguez v. United States. The canine was already on scene; the sniff occurred promptly; and the opinion treated the overall timeline as consistent with the ordinary completion of traffic-stop tasks. That factual framing allowed the court to conclude the sniff/search sequence did not become an impermissible detour beyond the stop’s mission.

C. Arrest and pat-down: marijuana odor plus corroborating indicators supported probable cause

Smith argued marijuana odor was insufficient—especially in Florida—but the court leaned on binding circuit precedent: United States v. Lueck holds that the recognizable odor of marijuana gives probable cause supporting a warrantless search. The court also emphasized that this case did not rest on odor alone: it involved a canine alert, officer-observed marijuana “shake” in the area where Smith had been sitting, and Smith’s escalating nervousness and agitation. The panel treated this aggregation of facts as more than enough for probable cause to search and arrest, making the ensuing discovery of fentanyl during the pat-down lawful.

3.3. Impact

  • Reinforcement of canine-alert probable cause in the Eleventh Circuit: By reapplying United States v. Tamari and United States v. Banks, the decision continues to treat a trained dog’s alert as a near-dispositive trigger for vehicle probable cause, so long as Rodriguez/Campbell timing constraints are satisfied.
  • Practical roadmap for litigating stop “prolongation” claims: The opinion signals that when a canine is present early and the sniff occurs within the normal cadence of traffic-stop tasks, a suppression claimant will face an uphill battle absent strong evidence of mission completion followed by added delay.
  • Marijuana odor remains a probable-cause factor notwithstanding state legalization complexity—at least on this record: The panel did not engage in a full analysis of whether and how Florida’s medical marijuana scheme might affect odor-based probable cause, because the argument was underdeveloped and not preserved. But the decision underscores that, in federal court within the Eleventh Circuit, United States v. Lueck remains the starting point and is difficult to dislodge without a carefully preserved, fully developed doctrinal argument.
  • Preservation discipline (certification requests and state-law pivots): The refusal to consider a late certification request reinforces that appellate strategy matters: state-law uncertainty arguments must be raised in the opening brief and, ideally, litigated below.

4. Complex Concepts Simplified

  • Probable cause vs. reasonable suspicion: Probable cause is a higher standard—roughly, a “fair probability” that evidence or contraband will be found (Illinois v. Gates). Reasonable suspicion (from Terry v. Ohio) is lower and permits brief investigative detention based on specific, articulable facts.
  • Automobile exception: If a car is readily mobile and police have probable cause to believe it contains contraband, they can search it without a warrant (Pennsylvania v. Labron; California v. Carney).
  • Canine alert: In this circuit, an alert by a trained narcotics dog can itself establish probable cause to search a vehicle (United States v. Tamari).
  • “Prolongation” of a traffic stop: Even if the initial stop is valid, officers may not extend it beyond the time needed to handle the traffic mission unless they have independent justification (Rodriguez v. United States; United States v. Campbell).
  • Clear error review: On appeal, factual findings are disturbed only when the appellate court is left with a “definite and firm conviction” a mistake was made (Anderson v. City of Bessemer City; In re Wagner). If two views of the evidence are plausible, the trial court’s choice generally stands.
  • Forfeiture by raising issues too late: Arguments first raised in a reply brief are generally not considered (United States v. Chalker; Lovett v. Ray), including late requests to certify state-law questions.

5. Conclusion

United States v. Nicholas Smith consolidates several familiar Fourth Amendment principles into a practical holding: observed traffic violations provide probable cause for a stop; a drug-dog alert during an otherwise timely stop supplies probable cause for a vehicle search under the automobile exception; and, in the Eleventh Circuit, marijuana odor—especially when corroborated by additional indicators like “shake,” a canine alert, and suspect behavior—continues to support probable cause for search and arrest. The opinion also serves as a procedural caution: litigants who wish to pivot to evolving state-law arguments or seek certification must preserve and develop those issues early, not for the first time on reply.