The U.S. Court of Appeals for the Eighth Circuit reversed a federal drug conspiracy conviction after finding that police violated the Fourth Amendment by unreasonably prolonging a traffic stop. In *United States v. Alex Olin Johnson* (8th Cir. 2026), the court agreed with the defendant's argument that evidence obtained during the extended stop should have been suppressed.
Alex Johnson had pleaded guilty to conspiring to distribute a controlled substance under 21 U.S.C. §§ 841(a)(1) and 846 after the U.S. District Court for the District of South Dakota denied his motion to suppress evidence. However, Johnson maintained his appeal, arguing that the district court erred in refusing to suppress evidence gathered during what he characterized as an unconstitutionally prolonged traffic stop.
The case originated from a multi-state drug trafficking investigation conducted by the South Dakota Division of Criminal Investigation. As part of this operation, investigators asked Officer Stevens to conduct a traffic stop on a vehicle leaving a surveilled apartment building. Officer Stevens initiated the stop on a nearby residential street, citing excessive window tint as the basis for the stop.
During the stop, Johnson informed Officer Stevens that his driver's license was suspended. Officer Stevens had Johnson exit his vehicle and join him in the patrol car. According to dash camera footage presented in the case, dispatch confirmed Johnson's suspended license status by the six-minute mark of the encounter.
Officer Stevens told Johnson he would receive a citation for driving without a valid license but only a warning for the window tint violation because the vehicle belonged to Johnson's brother. However, the officer stated they needed to wait for another officer equipped with a working window tint meter to obtain a reading for his report.
This waiting period became central to the circuit court's analysis. The court noted that while the officers waited, Officer Stevens possessed all the information and time necessary to complete the citation for driving without a license, which the court described as a task that typically requires minimal time to complete.
The Eighth Circuit's opinion, written by Circuit Judge Kobes, focused on the Fourth Amendment's protection against unreasonable searches and seizures. Under established precedent, traffic stops must be limited in scope and duration to the purpose that justified the initial stop. Once the objectives of the stop are completed or reasonably should have been completed, continued detention becomes constitutionally problematic without additional reasonable suspicion of criminal activity.
The court's ruling appears to align with Supreme Court precedent in cases like *Rodriguez v. United States* (2015), which held that authority for a traffic stop ends when tasks tied to the traffic infraction are completed or reasonably should have been completed. The high court has consistently held that prolonging a stop beyond this point violates the Fourth Amendment's protection against unreasonable seizures.
In this case, the circuit court determined that Officer Stevens unreasonably extended the duration of the stop beyond what was necessary to address the traffic violations that justified the initial encounter. The court found that waiting for another officer to obtain a window tint reading was not justified when the officer had already decided to issue only a warning for that violation.
The ruling has significant implications for similar drug enforcement operations that rely on pretextual traffic stops. Law enforcement agencies conducting drug trafficking investigations must ensure that any traffic stops remain within constitutional bounds and do not extend beyond the time reasonably required to complete the traffic-related objectives.
The case also highlights the importance of dash camera evidence in evaluating the constitutionality of police conduct during traffic stops. The detailed timeline provided by the video footage allowed the court to precisely evaluate when the stop's original purpose was fulfilled and when the continued detention became unreasonable.
Johnson's successful appeal demonstrates that defendants can challenge the admission of evidence even after entering guilty pleas, provided they preserve their right to appeal suppression issues. The case serves as a reminder that Fourth Amendment protections remain robust even in the context of drug enforcement operations.
The Eighth Circuit's decision reverses the district court's denial of Johnson's suppression motion and remands the case for further proceedings. This means Johnson's guilty plea may be withdrawn, and the government will need to proceed without the evidence obtained during the unconstitutionally prolonged portion of the traffic stop.
The ruling reinforces that law enforcement officers must adhere to constitutional limitations on the scope and duration of traffic stops, even when conducting investigations into serious crimes like drug trafficking. Courts will continue to scrutinize whether stops extend beyond their original justification and whether officers have reasonable suspicion to support any extension of the detention.