United States v. Carson: Timing Controls Rodriguez—Once Marijuana Odor Establishes Probable Cause, Later “Detours” Do Not Unlawfully Prolong the Stop; Sakyi Continues to Permit Drug-Based Frisks

I. Introduction

In United States v. Jermaine Carson, Jr. (4th Cir. July 8, 2026), the Fourth Circuit affirmed the denial of a motion to suppress a firearm found during a traffic stop frisk. The case arose after Asheville-area officers stopped a Toyota Highlander driven by Calvin Washington for driving with a suspended license. During the stop, Officer Hayes reported smelling marijuana and seeing drug paraphernalia. Officers searched and simultaneously removed occupants. Detective Escobedo frisked passenger Jermaine Derrick Carson, Jr.; Carson admitted he had a gun, and a loaded Glock was recovered from his pants leg.

Carson (a felon) was charged under 18 U.S.C. § 922(g)(1) and entered a conditional guilty plea preserving his right to appeal the suppression ruling. On appeal, he did not contest the initial stop; he argued (1) the stop was unlawfully prolonged under the Fourth Amendment, and (2) the frisk lacked reasonable suspicion that he was armed and dangerous.

II. Summary of the Opinion

The court affirmed on both issues:

  • No unlawful prolongation: Even assuming the initiating agent (Corthell) performed “detours” unrelated to the suspended-license mission (checking the vehicle/registered owner and discussing a dog), the district court did not clearly err in finding those actions occurred after or contemporaneously with Hayes’s detection of marijuana odor at 11:25:52 p.m.—an event that, under circuit precedent, supplied independent reasonable suspicion (indeed, probable cause) to expand the stop.
  • Frisk upheld: Under United States v. Sakyi, 160 F.3d 164 (4th Cir. 1998) and reaffirmed in United States v. Rooks, 596 F.3d 204 (4th Cir. 2010), reasonable suspicion that illegal drugs are in a vehicle permits officers to order occupants out and pat them down for weapons absent factors allaying safety concerns.

Judge Berner concurred in the judgment but criticized two aspects of existing doctrine: (1) Sakyi’s drug-to-gun presumption in an era of widespread marijuana legalization, and (2) the majority’s treatment of uncommunicated knowledge in light of United States v. Massenburg, 654 F.3d 480 (4th Cir. 2011).

III. Analysis

A. Precedents Cited

1. Standards of review and deference

  • United States v. Medley, 34 F.4th 326 (4th Cir. 2022): legal questions reviewed de novo; factual findings for clear error.
  • United States v. McBride, 676 F.3d 385 (4th Cir. 2012) (citing United States v. Edwards, 666 F.3d 877 (4th Cir. 2011)): evidence viewed in the government’s favor when suppression is denied.
  • United States v. Purks, 139 F.4th 388 (4th Cir. 2025) (quoting United States v. Pulley, 987 F.3d 370 (4th Cir. 2021)): strong deference to district-court credibility determinations.
  • United States v. Quarles, 330 F.3d 650 (4th Cir. 2003): de novo review of whether suspicion was sufficient to justify a frisk.

These cases mattered because Carson’s prolongation argument depended heavily on the timeline and on whether the district court credited Hayes’s testimony about the moment marijuana odor was detected. The panel emphasized that credibility calls belong primarily to the trial court.

2. Traffic stops, mission limits, and extensions

  • Delaware v. Prouse, 440 U.S. 649 (1979) (citing United States v. Martinez-Fuerte, 428 U.S. 543 (1976)): traffic stops are Fourth Amendment seizures.
  • Rodriguez v. United States, 575 U.S. 348 (2015): the “mission” of the stop sets its tolerable duration; unrelated inquiries are allowed only if they do not add time; extensions require independent reasonable suspicion.
  • Illinois v. Caballes, 543 U.S. 405 (2005): informs the “mission” concept adopted in Rodriguez.
  • United States v. Bowman, 884 F.3d 200 (4th Cir. 2018): officers may investigate unrelated matters so long as they do not lengthen the detention.
  • Arizona v. Johnson, 555 U.S. 323 (2009): traffic stops are “especially fraught with danger,” supporting certain safety-related checks.
  • United States v. Smart, 91 F.4th 214 (4th Cir. 2024) and United States v. Palmer, 820 F.3d 640 (4th Cir. 2016): a stop may be extended upon reasonable suspicion; Palmer is used for the temporal framing (defendant must show a constitutional violation before the moment reasonable suspicion/probable cause arises).
  • United States v. Frazier, 30 F.4th 1165 (10th Cir. 2022): offered a three-part framework for unlawful prolongation (diversion, prolongation, and lack of independent reasonable suspicion).

The majority used Rodriguez as the controlling principle and leaned on Palmer for the key move: once marijuana odor supplied independent suspicion (and probable cause), the “reasonable duration and mission of the stop evolved,” making later alleged detours constitutionally irrelevant to suppression unless Carson could show a pre-odor violation.

3. Marijuana odor and probable cause

  • United States v. Humphries, 372 F.3d 653 (4th Cir. 2004): “the odor of marijuana alone can provide probable cause” that marijuana is present.
  • United States v. Palmer, 820 F.3d 640 (4th Cir. 2016): after marijuana odor arises, the critical window for a prolongation claim is the period before the odor is detected.

Hayes’s claimed detection of marijuana at 11:25:52 p.m. was therefore a pivot point: it supplied the independent basis to expand the stop, and it provided the predicate for the drug-based frisk doctrine applied later.

4. Frisks during traffic stops; drugs-and-guns presumption

  • United States v. Robinson, 846 F.3d 694 (4th Cir. 2017) (en banc): to frisk, there must be a lawful stop and reasonable suspicion the person is armed and dangerous.
  • United States v. Sakyi, 160 F.3d 164 (4th Cir. 1998): when an officer reasonably suspects illegal drugs are in a vehicle during a lawful traffic stop, the officer may order occupants out and briefly pat them down for weapons absent factors allaying safety concerns.
  • United States v. Stanfield, 109 F.3d 976 (4th Cir. 1997): quoted in Sakyi for the premise “where there are drugs, there are almost always guns.”
  • United States v. Rooks, 596 F.3d 204 (4th Cir. 2010): reaffirmed Sakyi.
  • Brendlin v. California, 551 U.S. 249 (2007): passengers are seized during a traffic stop, so the stop’s lawfulness extends to them as detainees for Fourth Amendment purposes.

The majority applied Sakyi straightforwardly: because officers had reasonable suspicion that marijuana was in the Highlander, the weapon frisk of an occupant was permissible.

5. Collective knowledge doctrine and the Massenburg fault line

  • United States v. Massenburg, 654 F.3d 480 (4th Cir. 2011): limits reliance on uncommunicated information held by other officers when evaluating whether an individual officer had reasonable suspicion at the moment of action.

The majority included a footnote addressing Carson’s collective-knowledge argument, stating Hayes’s reasonable suspicion was “not imputed” to Corthell. Judge Berner’s concurrence counters that, despite the footnote, the majority effectively used Hayes’s uncommunicated observations to validate Corthell’s “detours,” in tension with Massenburg. This disagreement is significant for future Fourth Circuit prolongation litigation because it frames whether “independent reasonable suspicion” must be known to (or communicated to) the detouring officer, or whether its existence in the stop’s overall timeline suffices.

6. Judge Berner’s marijuana-legalization critique and cited authorities

  • United States v. Hemani, 608 U.S. -- (2026) (Alito, J., concurring, as quoted): invoked to highlight the federal government’s evolving tolerance and skepticism about equating marijuana use with dangerousness.
  • Short v. Hartman, 87 F.4th 593 (4th Cir. 2023): only en banc court may overrule prior panel precedent absent contrary Supreme Court authority.
  • United States v. Williams, 808 F.3d 238 (4th Cir. 2015): even de minimis prolongation can violate the Fourth Amendment absent suspicion or consent.
  • United States v. Sharpe, 470 U.S. 675 (1985): diligence and reasonable time frame in investigations.
  • United States v. Devaugh, 422 F. Supp. 3d 104 (D.D.C. 2019) (quoted): criticizes per se escalation of drug stops into intrusive encounters.
  • Selected sister-circuit cases discussed by Judge Berner: United States v. Garcia, 459 F.3d 1059 (10th Cir. 2006); United States v. Davis, 726 F.3d 434 (3d. Cir. 2013); United States v. Dubose, 579 F.3d 117 (1st Cir. 2009); United States v. Salazar, 945 F.2d 47 (2d. Cir. 1991); United States v. Colbert, 54 F.4th 521 (7th Cir. 2022).
  • Davis v. United States, 564 U.S. 229 (2011): exclusionary rule’s deterrence rationale, cited in the concurrence’s critique of incentives.

These authorities position the concurrence as an invitation to en banc reconsideration of Sakyi—especially as marijuana laws and social realities diverge from the factual assumptions underlying the “drugs imply guns” presumption.

B. Legal Reasoning

1. The “timing” rule for Rodriguez challenges (majority)

The majority treated the case as primarily temporal. Under Palmer, once an officer smells marijuana, the defendant must identify a Fourth Amendment violation that occurred before that moment. The panel accepted that Hayes’s detection of marijuana odor (credited by the district court) occurred at 11:25:52 p.m., only minutes into the stop, and that this observation supplied independent reasonable suspicion—indeed probable cause under Humphries.

Against that timeline, Carson’s claimed “detours” (vehicle/owner checks; discussing a dog) either occurred after 11:25:52 p.m. or could not be shown to have occurred before it, given the practical steps Corthell described (returning to the car, logging into CJLEADS with two-factor authentication, running standard driver checks first). Therefore, the panel concluded that any arguable detours did not “unconstitutionally extend” the stop because the stop had already legitimately evolved into a drug investigation.

2. The frisk analysis: Sakyi controls

On the frisk, the doctrinal path was direct:

  1. The stop was lawful as to Carson because passengers are seized in traffic stops (Brendlin v. California).
  2. Under United States v. Sakyi, reasonable suspicion that drugs are in the car authorizes ordering occupants out and patting them down for weapons absent factors allaying safety concerns.
  3. Because the officers had reasonable suspicion that marijuana was present (odor; scale with residue), Escobedo’s frisk was lawful under binding Fourth Circuit precedent (Sakyi; reaffirmed by Rooks).

3. The concurrence’s doctrinal cautions

Judge Berner’s concurrence underscores two pressure points:

  • Sakyi’s presumption under modern marijuana law: The concurrence argues that equating marijuana proximity with dangerousness is increasingly untenable, particularly given evolving state legalization, shifting enforcement practices, and the Supreme Court’s discussion in United States v. Hemani. While acknowledging panel constraint (Short v. Hartman), the concurrence flags Sakyi as ripe for en banc reexamination.
  • Massenburg and uncommunicated information: The concurrence would resolve the prolongation issue at the “prolongation” prong (no measurable extension) rather than by treating Hayes’s uncommunicated probable cause as “independent reasonable suspicion” justifying Corthell’s detours, warning that doing so risks incentivizing unconstitutional “roll the dice” searches contrary to Massenburg and the deterrent logic discussed in Davis v. United States.

C. Impact

1. Traffic-stop litigation: the primacy of the “probable cause moment”

For future Rodriguez challenges in the Fourth Circuit, Carson reinforces that suppression battles will often turn on (a) the precise time when independent suspicion arises (e.g., odor detection), and (b) whether the defendant can prove an unlawful extension before that moment. Practically, defendants will focus on contesting the credibility, timing, and documentation of odor testimony, while the government will emphasize contemporaneous body-worn camera timestamps and district-court credibility findings (bolstered by Purks/Pulley deference).

2. Doctrinal tension: Massenburg and the scope of “independent suspicion”

The split between the majority’s framing (failure at the “independent reasonable suspicion” prong) and the concurrence’s warning (uncommunicated knowledge and Massenburg) signals a developing fault line. Litigants can be expected to test whether Carson effectively permits a stop’s objective “evolution” based on any officer’s observations even if not communicated to the officer conducting allegedly unrelated tasks—and, if so, how that reconciles with Massenburg’s communication requirement in other Fourth Amendment contexts.

3. Frisks and marijuana: Sakyi remains binding but under mounting pressure

On frisks, Carson confirms that, for now, Sakyi continues to authorize pat-downs of vehicle occupants when officers reasonably suspect drugs in the car, including marijuana. But Judge Berner’s concurrence—grounded in changing legalization, enforcement discretion, and Hemani—invites renewed challenges aimed at en banc reconsideration or at narrowing the presumption (for example, limiting it to trafficking rather than personal-use indicators, as some sister circuits do).

IV. Complex Concepts Simplified

  • “Mission” of a traffic stop: The constitutionally permitted tasks tied to the reason for the stop (e.g., license status, warrants, registration). Under Rodriguez, officers may not add time for unrelated investigations unless there is consent or independent reasonable suspicion.
  • Reasonable suspicion vs. probable cause: Reasonable suspicion is a lower threshold requiring specific, articulable facts suggesting criminal activity; probable cause is a higher threshold suggesting a fair probability evidence of a crime will be found. In the Fourth Circuit, marijuana odor can supply probable cause (Humphries).
  • “Prolongation”: Any added time to the stop beyond what the mission requires. Even small extensions can violate the Fourth Amendment if unsupported (Williams).
  • Frisk (pat-down) for weapons: A limited search of outer clothing permitted when an officer reasonably suspects the person is armed and dangerous. In the Fourth Circuit, Sakyi supplies a presumption of danger when drugs are suspected in a vehicle during a traffic stop.
  • Collective knowledge doctrine: In some circumstances, one officer may act on another officer’s communicated instruction/knowledge. Massenburg limits using uncommunicated information to justify an officer’s action after the fact.

V. Conclusion

United States v. Carson (published) delivers two core takeaways for Fourth Amendment practice in the Fourth Circuit. First, in a Rodriguez prolongation challenge, the critical question is often when independent suspicion (here, marijuana odor) arose; once it does, later investigative steps—even if arguably unrelated to the original traffic mission—will not support suppression absent a proven pre-suspicion constitutional violation. Second, Sakyi remains controlling: reasonable suspicion of drugs in a vehicle permits frisking occupants for weapons, though the concurrence forcefully argues that marijuana’s changing legal status may warrant en banc reconsideration of the presumption’s continuing constitutional fit.