Odor of Burnt Marijuana Justifies Prolonged Detention and Automobile-Exception Search; Credibility Findings Control Suppression Review

1. Introduction

In United States v. Antoine Gaither (6th Cir. Apr. 28, 2026) (unpublished), the Sixth Circuit affirmed the denial of a motion to suppress a handgun discovered after a traffic stop that began with a stop-sign violation. The central Fourth Amendment disputes were (1) whether the deputy lawfully ordered the driver out of the vehicle, and (2) whether the deputy had a sufficient basis—based on the odor of marijuana—to extend the stop and search the vehicle without a warrant.

The key factual pivot was the district court’s finding that Deputy Danielski credibly testified that he smelled burnt marijuana emanating from Gaither’s car before and during the encounter. That credibility determination drove the Fourth Amendment analysis: once the odor finding stood, Sixth Circuit precedent supplied both reasonable suspicion to extend the stop and probable cause to search the vehicle under the automobile exception.

Procedurally, Gaither pleaded guilty to one count of felon-in-possession under 18 U.S.C. § 922(g)(1) (Count II), while reserving the right to appeal the suppression ruling. The appeal thus focused narrowly on the legality of the officers’ conduct leading up to the discovery of the firearm.

2. Summary of the Opinion

The Sixth Circuit held:

Ordering the driver out of the car was lawful because officers may always order drivers out during a lawful traffic stop.
The stop was permissibly prolonged because the odor of burnt marijuana provided reasonable suspicion of criminal activity.
The vehicle search was lawful because the odor of marijuana supplied probable cause, triggering the automobile exception.
Gaither’s contrary arguments largely attacked credibility, and appellate courts generally do not revisit district-court credibility findings.

Accordingly, the court affirmed the district court’s denial of suppression.

3. Analysis

A. Precedents Cited

1) Authority to order a driver out during a lawful stop

The panel treated the “order-out” question as settled:

United States v. Fellmy, 165 F.4th 501, 505 (6th Cir. 2026) (per curiam) — reiterated that “officers may always order drivers out of their car during a lawful police stop.”
Pennsylvania v. Mimms, 434 U.S. 106, 111 n.6 (1977) — foundational Supreme Court authority permitting officers to order drivers out as a minimal intrusion justified by the inherent safety risks of traffic stops.
Whren v. United States, 517 U.S. 806, 813 (1996) — supports the objective Fourth Amendment framework: the legality of the stop does not turn on officers’ subjective motives when there is an objective basis for the stop.

Gaither argued for a narrowing construction—i.e., that an officer must have individualized safety concerns before ordering a driver out. The court rejected that invitation as inconsistent with Pennsylvania v. Mimms, which treats the safety rationale as categorical in the traffic-stop setting.

2) Limits on prolonging traffic stops and the reasonable-suspicion gateway

On the “extended stop” issue, the panel relied on the familiar mission-based framework:

United States v. Lott, 954 F.3d 919, 923 (6th Cir. 2020) — restated that a stop may not be prolonged beyond the time required to complete the traffic mission, while recognizing that drug-related indicators can supply reasonable suspicion supporting extension.
Illinois v. Caballes, 543 U.S. 405, 407 (2005) — provided the quoted principle that an otherwise lawful stop cannot be prolonged beyond the time reasonably required to complete its mission.
United States v. Stepp, 680 F.3d 651, 661 (6th Cir. 2012) — supplied the standard for permissible extension: “a reasonable and articulable suspicion that criminal activity is afoot.”

The court then treated the marijuana odor finding as supplying that “reasonable and articulable suspicion,” allowing investigative steps beyond the traffic infraction.

3) Appellate treatment of credibility determinations

The court characterized Gaither’s argument—questioning whether the deputy truly smelled burnt marijuana—as an attack on the district court’s credibility finding. It cited:

United States v. Reid, 357 F.3d 574, 582 (6th Cir. 2004) — credibility determinations are “ordinarily unreviewable.”
Matthews v. Abramajtys, 319 F.3d 780, 788 (6th Cir. 2003) — appellate courts cannot “reweigh the evidence or redetermine the credibility of the witnesses whose demeanor has been observed by the trial court.”

These cases were decisive because once the district court found the deputy credible, the legal consequences of marijuana odor followed under binding Fourth Amendment doctrine in the circuit.

4) Probable cause, the automobile exception, and marijuana odor

The court then applied automobile-exception precedent:

United States v. Lyons, 687 F.3d 754, 770 (6th Cir. 2012) — stated the automobile exception rule: a warrantless vehicle search is permitted with probable cause to believe the vehicle contains contraband or evidence.
United States v. Elkins, 300 F.3d 638, 659 (6th Cir. 2002) — held that the smell of marijuana from a vehicle “can by itself establish probable cause for a search.”

By reaffirming United States v. Elkins, the panel treated marijuana odor as sufficient—standing alone—to satisfy probable cause and thus to justify a full vehicle search under the automobile exception.

B. Legal Reasoning

1) The “order-out” rule applied categorically

The court’s first step was to identify the stop as lawful (a stop-sign violation; undisputed). Under Pennsylvania v. Mimms, an officer may order the driver out of the vehicle as a routine safety measure. United States v. Fellmy reinforced that this is always permissible during a lawful stop, and Whren v. United States foreclosed any attempt to reframe the legality around the officer’s subjective intent.

2) Prolongation: odor as reasonable suspicion

The panel then addressed the line of cases restricting extensions of traffic stops. Under Illinois v. Caballes and United States v. Lott, a traffic stop cannot last longer than its mission without additional justification. Under United States v. Stepp, however, reasonable suspicion of additional criminal activity permits extension.

The court held that the deputy’s detection of burnt marijuana odor provided that reasonable suspicion, legitimizing the continued detention and investigation even if those steps moved beyond writing a traffic citation.

Notably, the court rejected Gaither’s “end-run” framing. The panel reasoned it would be anomalous to allow officers to order drivers out during a stop for a traffic violation but to prohibit the same order when there is reason to suspect broader criminal activity. In the court’s view, the Fourth Amendment does not require such an inversion.

3) Probable cause: odor as a sufficient basis for a vehicle search

After accepting the district court’s factual finding that the deputy smelled burnt marijuana, the panel treated the probable-cause question as straightforward. Under United States v. Elkins, marijuana odor from a vehicle can itself establish probable cause. Under United States v. Lyons, probable cause triggers the automobile exception, permitting a warrantless search of the vehicle for contraband or evidence.

Thus, the vehicle search was upheld. And because the suppression challenge was framed as the handgun being the “fruit of an unlawful search,” once the underlying detention and search were deemed lawful, the derivative-evidence argument collapsed as well.

4) Credibility as the linchpin on appeal

Gaither attempted to undermine the odor finding by arguing that “burnt” marijuana was a post-hoc embellishment because the deputy initially said only “weed” on scene and used “burnt” later in a report. The district court rejected this as a matter of common sense, and the Sixth Circuit found no clear error—emphasizing that appellate courts do not second-guess credibility determinations under United States v. Reid and Matthews v. Abramajtys.

C. Impact

1) Reinforcement of marijuana-odor doctrine in the Sixth Circuit

This opinion reaffirms that, at least within the Sixth Circuit’s existing framework, marijuana odor remains powerful Fourth Amendment currency:

It can supply reasonable suspicion to extend a stop.
It can supply probable cause to search the vehicle under the automobile exception.

While unpublished and “not recommended for publication,” the decision signals continuity: the panel applied United States v. Elkins without qualification and treated the issue as doctrinally settled once the odor finding was credited.

2) Litigation focus shifts to factual development and credibility

The decision illustrates a recurring suppression dynamic: when the governing legal rules are clear, outcomes often hinge on whether the district court credits an officer’s account (here, the claimed smell of burnt marijuana). Because credibility findings are highly insulated on appeal, suppression litigation in similar cases is likely to concentrate on:

body-worn camera audio/video context,
consistency between on-scene statements and reports,
cross-examination on training/experience detecting odors, and
objective corroboration (e.g., later discovery of marijuana, as occurred here).

3) Practical effects on roadside encounters

The court’s reaffirmation of Pennsylvania v. Mimms and its rejection of a safety-concerns limitation strengthens officers’ discretion to control the scene during traffic stops. Combined with the marijuana-odor rule, the decision supports a broader enforcement pathway: traffic stop → odor detected → extended detention → vehicle search.

4. Complex Concepts Simplified

Reasonable suspicion: A specific, articulable basis to suspect criminal activity—less than probable cause. Here, the odor of burnt marijuana supplied reasonable suspicion to extend the stop beyond the traffic mission.
Probable cause: A fair probability that contraband or evidence will be found. Under United States v. Elkins, marijuana odor can itself establish probable cause to search a vehicle.
Automobile exception: A rule allowing warrantless searches of vehicles when probable cause exists, recognized in this opinion via United States v. Lyons.
“Mission” of a traffic stop: The tasks tied to addressing the traffic violation (license, registration, citation). Under Illinois v. Caballes and United States v. Lott, officers generally may not extend the stop beyond that mission absent additional justification.
Clear error vs. de novo review: Factual findings are reviewed for “clear error,” while legal conclusions are reviewed “de novo.” The opinion quotes this standard from United States v. Fellmy.
Credibility determinations: Trial courts’ decisions about whether to believe a witness, especially based on demeanor. The Sixth Circuit stressed these are “ordinarily unreviewable” under United States v. Reid and cannot be reweighed under Matthews v. Abramajtys.
Fruit of the poisonous tree: Evidence may be suppressed if it is derived from an illegal search or seizure. Here, because the stop, extension, and vehicle search were upheld, the handgun was not treated as tainted fruit.

5. Conclusion

United States v. Antoine Gaither underscores three doctrinal takeaways in Sixth Circuit Fourth Amendment practice: (1) under Pennsylvania v. Mimms and United States v. Fellmy, officers may order a driver out of a vehicle during a lawful stop; (2) the odor of burnt marijuana can provide reasonable suspicion to extend a stop under United States v. Stepp; and (3) marijuana odor can supply probable cause for a warrantless vehicle search under the automobile exception, consistent with United States v. Elkins and United States v. Lyons. The opinion also highlights a practical appellate reality: when suppression turns on an officer’s sensory observations, the district court’s credibility findings often determine the case, and are rarely disturbed on appeal.