United States v. Munoz (8th Cir. 2025)

Federal Case – Eighth Circuit Court of Appeals

In United States v. Munoz, the Eighth Circuit Court of Appeals addressed a familiar issue in K9 case law—how far is too far when a drug dog sniffs (and touches) a car during a traffic stop?

The case involved three defendants—Ashley Chacon, Emiliano Nava Munoz, and Valentin Nava Munoz—who were stopped and ultimately charged with distributing massive amounts of methamphetamine. Chacon was pulled over for speeding in Iowa. During the stop, an officer asked her to sit in his patrol vehicle while he completed the usual paperwork and asked about her travel plans. Within five minutes, a second officer arrived with a trained K9. The dog performed an open-air sniff and alerted to the back of the car. During the sniff, the dog made brief contact with the car’s exterior. This prompted a full vehicle search that uncovered more than 50,000 grams of meth.

Chacon challenged the search, arguing that the stop was unlawfully prolonged to allow time for the K9 to arrive and that the dog’s contact with the car amounted to an unconstitutional search. The court rejected both claims.

On the timing issue, the court found that the stop wasn’t impermissibly extended. The officer was still engaged in tasks directly related to the traffic violation when the dog sniff occurred. This fell squarely within the guidelines set by Rodriguez v. United States (2015), where the Supreme Court held that a traffic stop becomes unlawful when it is prolonged beyond the time needed to handle the reason for the stop.

But it was the second issue—whether the K9’s physical contact with the car violated the Fourth Amendment—that’s particularly worth highlighting. Chacon argued that this brief contact constituted an unlawful trespass and thus an illegal search. The Eighth Circuit didn’t agree.

The court emphasized that not all dog contact is created equal. In this case, the dog wasn’t commanded or prompted to make contact; it acted on its own. This matters because, under Eighth Circuit precedent, a dog’s instinctive behavior during a lawful sniff doesn’t trigger constitutional protections unless the contact results from police misconduct.

In fact, the court referenced video footage that showed no indication the officer directed the dog to touch the car. The dog’s actions were quick and consistent with its training. The court leaned on its prior decision in United States v. Lyons, where a dog that poked its head into an open window was found not to have conducted a search because it acted instinctively, not at the officer’s direction.

While acknowledging that newer cases—like United States v. Pulido-Ayala—have cast doubt on the significance of whether a dog’s actions are “instinctive” or “directed,” the court said it didn’t need to settle that issue here. Why? Because even if the brief contact were problematic, the dog’s alert alone gave officers probable cause to search the vehicle. So either way, the evidence would have been lawfully discovered.

On appeal, Emiliano and Valentin Munoz also challenged sentencing enhancements that labeled them as supervisors in the drug operation and as people who maintained drug premises. Both enhancements were upheld. The court found that Emiliano used two different houses to store cash and drugs and to coordinate trafficking activity, including recruiting others. Valentin, too, played a leadership role—at one point instructing Emiliano on how much meth to bring to a deal and where to meet.

In the end, the court affirmed the convictions and sentences for all three defendants.

What This Means for K9 Cases

This decision is a reminder that courts are still willing to uphold K9 sniffs—even when the dog makes brief contact with a vehicle—as long as the stop itself is lawful and the contact isn’t caused by officer misconduct. It also illustrates how courts rely heavily on video evidence to determine what actually happened during a sniff. If the dog acts on its own and the officer stays hands-off, the courts are unlikely to see a Fourth Amendment violation.

Binding Jurisdiction:

This case is now binding precedent in all states within the Eighth Circuit: Arkansas, Iowa, Minnesota, Missouri, Nebraska, North Dakota, and South Dakota.