Two Denver police officers did not have reasonable suspicion of criminal activity when they boxed in a driver with their patrol car, the Colorado Supreme Court decided, deeming the officers’ actions an unconstitutional seizure under the Fourth Amendment.

The decision on Monday upheld a lower court’s ruling that suppressed evidence from Alexander Brown’s February 2020 encounter with police. Prosecutors charged Brown with possession of a weapon by a previous offender after he admitted that a gun discovered during the interaction was his.

Although District Court Judge Jay S. Brown determined that officers seized Brown at the point when they threatened to call a drug-detection dog, he decided the initial contact with Brown in the parking lot of an apartment complex was consensual. The Supreme Court disagreed, finding that the seizure actually happened earlier, when the officers pulled their car behind Brown’s and prevented him from leaving.

“No reasonable person in Brown’s position would have felt free to leave at that point,” wrote Justice Maria E. Berkenkotter in the March 7 opinion. “And it is undisputed that the officers did not have reasonable suspicion of criminal activity when they blocked in the Ford in order to approach its occupants.”

Under the Fourth Amendment, which prohibits unreasonable searches and seizures, police have “seized” a person by restraining their movement, such as through an arrest. Although arrests require probable cause of a crime, an officer may initiate a briefer investigatory stop based only on reasonable suspicion. A consensual encounter with police, in contrast, is not a seizure.

Officers Jesus Galvan and Christina King had spotted a vehicle involved in a hit-and-run and two others without license plates in an apartment complex’s parking lot on the evening of Feb. 18, 2020. While they were checking out the parked cars, they noticed a Ford Focus with two occupants inside. Although they ran the license plate and found nothing amiss, the officers pulled their vehicle behind the car and saw smoke coming from the windows.

Galvan and King walked up to the car, where Brown was sitting in the driver’s seat and a woman was in the passenger’s seat. Galvan smelled marijuana inside.

“Anything illegal in the car? Can I get your permission to check the car?” Galvan asked. Brown declined to allow the search.

“OK, if I call a dog over here he isn’t going to hit on narcotics?” Galvan asked. Brown said no. Galvan then indicated he would summon a drug-detection dog and returned to his car.

However, Galvan realized there was no dog available. Upon returning to the car, Brown admitted that he had marijuana. Despite his prior comments about narcotics, Galvan responded he was “not worried about the weed,” but instead firearms. Brown did grant Galvan permission to check for weapons.

Brown’s passenger eventually asked to return to her apartment. While Galvan agreed to let her, King patted her down and found a handgun. Brown quickly took responsibility for the gun, and the officers placed Brown in handcuffs.

The defense asked Grant to suppress the evidence from the illegal seizure of Brown. Grant agreed, finding the interaction began as a consensual encounter but escalated to an investigatory stop that implicated Brown’s constitutional rights when Galvan indicated he would call a drug-sniffing dog.

Although the Denver District Attorney’s Office argued that the officers had reasonable suspicion that a crime was occurring — public consumption of marijuana — Grant noted that Galvan explicitly said he was not concerned with cannabis.

On appeal, the prosecution claimed that Grant improperly considered Galvan’s intent not to pursue a marijuana-related arrest. Because the officers saw Brown and his passenger smoking marijuana in public, they had not only reasonable suspicion, but probable cause of a crime. As such, the officers were “objectively reasonable in detaining Brown, who then consented to a search of his person and vehicle,” the district attorney’s office argued.

Brown, meanwhile, argued that the trial judge was correct to find an unconstitutional seizure had taken place, but that it actually began when the officers boxed in his car and prevented him from leaving.

“No reasonable person placed in that position would feel that they were free to leave when placed in that position, and certainly a young black man such as Mr. Brown would not feel free to leave,” Deputy State Public Defender K. Alexis Sheek wrote to the Supreme Court.

The justices agreed with Brown. Although the officers had reasonable suspicion of a crime once they smelled marijuana at the window of Brown’s car, they had already seized Brown and violated his Fourth Amendment rights by blocking his vehicle.

“All the officers knew at that point in time was that the car was occupied and that some type of smoke was coming out of the cracked windows,” Berkenkotter wrote. “It was not until they contacted Brown that Officer Galvan smelled burnt marijuana and then had reasonable suspicion that the occupants were engaged in the open and public consumption of marijuana.”

In February, the court held oral arguments in the district attorney’s appeal, which focused largely on the procedural issue of whether defendants could raise challenges to a lower court’s suppression ruling at the same time prosecutors were pursuing their appeal to the Supreme Court. Berkenkotter briefly explained that if the defendant’s arguments were “intimately related to or interwoven with” the subject of the appeal, the justices were allowed to consider those.

Because the timing of Brown’s seizure was closely related to the suppression order, she added, the court elected to decide the issue he raised.

The case is People v. Brown.