Stoll and a friend were stopped after two sheriff's deputies observed that the SUV Stoll was driving had a "white light from the lamp illuminating the license plate." The deputies believed that "white light visible from a vehicle moving forward" violated a state statute, A.R.S. § 28-931(C). The deputies had followed the SUV from a convenience store where the deputies stated they had smelled "burnt marijuana" coming from the area where Stoll and his friend were in the store.
Stoll was arrested after the officers found evidence that he was intoxicated including "a breathalyzer test [that] measured his alcohol concentration at .165." Stoll "moved to suppress the evidence seized during the stop, arguing that the deputies' belief about white light from a license plate light was not supported by any statute." The trial judge agreed with Stoll, finding none of the state's proffered reasons to keep in the evidence compelling.
Later on, in December of 2014, the state asked the court to reconsider charges against Stoll because of a U.S. Supreme Court decision, Heien v. North Carolina, arguing the deputies made "a reasonable mistake of law in interpreting § 28-931(C) when they concluded Stoll's license plate lamp violated state law." Stoll contested this assertion, contending that "the statute clearly and unambiguously compels a conclusion that the lamp was not in violation, and the deputies' interpretation of the statute was not objectively reasonable." The lower court ruled in favor of the state, finding the deputies mistake reasonable because "any rear-facing white light on a vehicle other than a backup lamp violated § 28-931(C)." Stoll was also denied on a motion to reconsider and at trial was subsequently convicted and sentenced. Stoll then appealed.
The appellate court looked at whether or not the white light from the license plate lamp was in fact in violation of the code section in question, and would thereby give officers reasonable suspicion to stop the Stoll. The court found that the language of the code section permitted a white light on a license plate, stating "[b]ecause this lamp fell within an express exception in § 28-931(C)(2), there was no legally correct basis for the deputy to investigate a violation of § 28- 931(C)." The court also looked at whether the license plate lamp violated any other code section and concluded it did not.
The court then determined if the deputies mistake was reasonable. In the Supreme Court case that the state used to get Stoll's case reconsidered, the high court had ruled that "reasonable suspicion supporting a traffic stop can rest upon a reasonable mistake of law." The mistake must be objectively reasonable, however.
In Stoll's case, the state contended that "a reasonable reader could conclude the phrase 'the light illuminating the license plate' refers to the visible light shining on the license plate from the license plate lamp, rather than the license plate lamp itself." The court reject this stating that the "[t]he implication is that white light shining from the license plate lamp directly to the rear is in violation, whereas white light reflected off of the license plate before shining to the rear is not." In addition, the state argued that the white lamp could be mistaken for a backup lamp, but the court also found this reasoning unpersuasive because the license plate lamp is expressly allowed by the statute to be white. The court also pointed out that the section in question is called "Lamp colors," stating "[t]he statute regulates the color of lamps, not the trajectory of light emitted by particular lamps."
The court stated that "[w]e agree with the Seventh Circuit's reasoning that 'Heien does not support the proposition that a police officer acts in an objectively reasonable manner by misinterpreting an unambiguous statute.'" In addition, the court did not find the officer's incorrect training a compelling justification.
The court concluded the officers interpretation was not objectively reasonable. The appeals court then vacated Stoll's conviction, as well as his sentence. They also reversed the motion for reconsideration brought by the state and then they remanded the case back to the trial court.