Fourth Circuit Clarifies Vehicle Protective Searches and Bounds on Traffic-Stop Extensions

Introduction

United States v. Joseph Dadisman is a 2025 decision of the Fourth Circuit that refines two critical aspects of Fourth Amendment traffic‐stop jurisprudence: (1) the scope of a “protective search” for weapons when a suspect is free to move around his vehicle, and (2) the proper analysis for determining whether a brief investigative detention has been unlawfully prolonged by unrelated law‐enforcement inquiries such as a drug‐detection dog sniff. In Dadisman, a West Virginia sheriff stopped the defendant’s motorcycle for an invalid registration, frisked him, retrieved a handgun from a side bag, then waited to conduct a canine sniff that uncovered over 500 grams of methamphetamine. Dadisman challenged the validity of the stop, the protective search of his motorcycle, and the extension of the detention beyond the time needed to complete the traffic‐violation mission. The Fourth Circuit affirmed the weapon‐search ruling but vacated and remanded on the duration issue, instructing the district court to apply the two‐step framework laid down in Rodriguez v. United States and its own precedents to determine whether the detention was unduly prolonged.

Summary of the Judgment

The Fourth Circuit’s unpublished opinion, authored by Senior Judge Keenan, addressed three issues on appeal:

Pretext for the traffic stop: The court held that Dadisman waived any challenge to the stop’s inception by failing to object to the magistrate judge’s report. Even under plain‐error review, the stop was lawful because the motorcycle displayed an invalid registration.
Protective search for weapons: The court affirmed the district court’s conclusion that once Dadisman admitted to storing a loaded firearm in a mesh bag on his motorcycle—while standing unrestrained ten feet away—Sheriff Carpenter lawfully conducted a limited search of the bag under Terry v. Ohio and Michigan v. Long to secure the weapon and ensure officer safety.
Length of detention and dog sniff: The Fourth Circuit concluded that the district court erred by assuming, without analysis, that the roughly ten‐minute stop (three–and–a–half minutes to remove the gun plus about six–and–a–half minutes of conversation before the K-9 arrived) was inherently reasonable because the motorcycle could not lawfully depart the scene. The appellate court vacated the suppression ruling on this point and remanded, instructing the district court to apply the “diligent pursuit” test for the traffic‐stop mission and then to determine whether any additional delay constituted an impermissible extension absent reasonable suspicion of drug activity.

Analysis

Precedents Cited

Terry v. Ohio, 392 U.S. 1 (1968): Established the protective‐search exception allowing frisks for officer safety when a suspect is reasonably believed to be armed.
Michigan v. Long, 463 U.S. 1032 (1983): Extended Terry to vehicle compartments when officers suspect the arrestee may access weapons.
Whren v. United States, 517 U.S. 806 (1996): Held that subjective officer motives do not invalidate a stop based on an objectively valid traffic violation.
Rodriguez v. United States, 575 U.S. 348 (2015): Articulated the two‐step analysis for traffic‐stop extensions: (1) compare time taken to complete the stop’s “mission” with reasonable diligence, and (2) if exceeded, ask whether a new reasonable‐suspicion justification arose for the added detention.
United States v. Hill, 852 F.3d 377 (4th Cir. 2017): Applied Rodriguez and upheld a 20‐minute stop where officers diligently handled the traffic tasks while awaiting a drug dog.
United States v. Perez, 30 F.4th 369 (4th Cir. 2022): Reaffirmed that a dog sniff is lawful if it does not extend the stop beyond the time needed to issue citations, tow the vehicle, and otherwise complete the traffic mission.

Legal Reasoning

The Fourth Circuit’s reasoning unfolds in three parts:

1. Waiver of the Pretext Challenge

Because Dadisman did not object below to the magistrate judge’s finding that the invalid registration rendered the stop lawful, he waived appellate review under Federal Rule of Criminal Procedure 59 and §636(b)(1)(C). The court noted that even if plain‐error review applied, Whren forecloses invalidating a stop when an objectively valid basis exists.

2. Protective Search under Terry/Long

After removing Dadisman from the motorcycle and frisking him, Sheriff Carpenter saw loose ammunition in a mesh pouch. When Dadisman admitted the pouch held his handgun, Carpenter reached into the pouch—while Dadisman stood ten feet away—and secured the weapon. The court held that Terry and its vehicular branch in Long permit this limited “protective search” because (a) the officers reasonably believed Dadisman was armed and dangerous, and (b) the search was narrowly tailored to locating the weapon and eliminating the risk to officers.

3. Duration of the Stop and the Dog Sniff

Applying Rodriguez, the court explained that the district court must first determine the time reasonably required “to complete the mission of the stop”—here, verifying registration, licensing, and arranging towing. If the actual detention (approximately ten minutes) exceeded the diligently required time, the court must then ask whether the additional delay was for a purpose unrelated to the stop (the canine sniff) and, if so, whether officers had reasonable suspicion of drug trafficking. Because the district court assumed reasonableness without walking through these steps, the Fourth Circuit vacated and remanded for a full “diligent pursuit” analysis on the existing record.

Impact

United States v. Dadisman has far‐reaching implications for law enforcement and defense practice:

Traffic‐stop training must emphasize strict timelines: officers should document the start and end of each “mission‐related” task (e.g., computer checks, writing citations, authorizing towing) to show diligence.
Prosecutors and trial courts will apply the two‐step Rodriguez framework more rigorously, particularly in close cases where drug‐dog requests coincide with routine traffic procedures.
Courts will likely require more precise time accounting during suppression hearings, reducing factual ambiguity concerning “unaccounted‐for” periods.
The decision confirms that vehicular Terry searches extend to non‐passenger compartments—here, detachable motorcycle bags—when officers reasonably believe weapons are present.
Defense counsel should preserve objections to all aspects of a stop (inception, scope, duration) at the suppression‐hearing stage to avoid waiver on appeal.

Complex Concepts Simplified

Traffic-Stop Mission: All tasks necessary to enforce the traffic violation—running registration and license checks, preparing tickets, arranging to tow an unregistered vehicle.
Protective Search (Terry Frisk): A limited pat‐down or grab of compartments to discover weapons when an officer reasonably suspects a detainee is armed and dangerous.
Dog Sniff: A canine’s external examination of a vehicle’s surfaces and containers for narcotics odors; considered “non‐intrusive” if it does not prolong the stop.
Reasonable Suspicion vs. Probable Cause:
- Reasonable Suspicion—a minimal quantum of objective justification, based on specific facts, to briefly detain for investigative purposes.
- Probable Cause—a fair probability that evidence of a crime will be found, authorizing arrests and full searches under a warrant or recognized exception.
Waiver vs. Plain Error:
- Waiver—failure to object at trial forfeits the right to raise the issue on appeal (absent extraordinary circumstances).
- Plain Error—appellate courts may correct a serious legal mistake not preserved below, but only if the error affected substantial rights and the fairness or integrity of judicial proceedings.

Conclusion

United States v. Dadisman affirms that protective searches for weapons during lawful traffic stops extend to vehicle compartments—even on motorcycles—so long as officers reasonably fear for their safety. More significantly, it reinforces Rodriguez’s two‐step framework for assessing whether a dog sniff (or any unrelated inquiry) unlawfully prolongs a stop: courts must first measure the time reasonably needed to complete the stop’s traffic‐related mission with diligence, and then ask whether any additional delay was justified by new reasonable suspicion. By vacating the suppression ruling on duration grounds and remanding for a proper analysis, the Fourth Circuit sends a clear message that traffic‐stop timelines and purposes will be scrutinized—and evidence obtained during questionable extensions may be suppressed.