COA affirms suppression order because officer’s mistake of law did not provide reasonable suspicion for traffic stop.
State v. Michael P. Bundy, 2025AP1072, 6/25/26, District IV (not eligible for publication); case activity
The COA affirmed the circuit court’s order suppressing the fruits of a traffic stop because an officer’s mistake of law regarding the driver’s suspected violation of the window tinting regulation did not provide reasonable suspicion to stop the vehicle.
A La Crosse police officer stopped a vehicle driven by Michael Bundy because he suspected its rear windows were too dark to comply with the Wisconsin Administrative Code requiring at least 35 percent of light to pass through. Wis. Admin. Code § Trans 305.32(5)(b) and (6). While talking to Bundy, the officer detected signs that he might be intoxicated and saw an open intoxicant in the vehicle. Bundy was arrested and charged with operating while intoxicated and with a prohibited alcohol concentration as third offenses. (¶¶ 2-5).
Bundy filed a motion to suppress the fruits of the traffic stop, arguing that the officer did not have reasonable suspicion of any equipment violation or driving offense. The officer testified at an evidentiary hearing that window tints must allow at least 35 percent of light to pass through the windows and that Bundy’s vehicle registered 20 percent on the tint meter. The officer was unaware that the Administrative Code allows tinting that provides less than 35 percent of light if the window is tinted by the manufacturer and is installed as part of the original manufacturing process. Wis. Admin. Code § Trans 305.32(5)(b) and (6). Bundy told the officer during the traffic stop that the tint on the windows was “factory tint.” (¶ 3). The officer testified he was not trained to differentiate between factory-installed and after-market tints and “appeared to assume that factory-installed tints would have to comply with the 35-percent transmission standard.” (¶ 10).
The circuit court granted the motion to suppress because the tint was factory installed and therefore legal. (¶ 11).
The parties did not dispute on appeal that Bundy’s windows allowed 20 percent of light to pass through and that the tinted windows were factory installed. However, the State argued that the possibility the window tint was factory installed provided an “innocent explanation” and an officer does not need to rule out an innocent explanation to have reasonable suspicion to stop a vehicle. (¶ 18).
The Court considered the State’s argument “compelling” but for caselaw establishing that an officer’s mistake of law regarding vehicle equipment violations does not support reasonable suspicion. (¶¶ 20-23) (citing Houghton and Lerdahl). The Court concluded:
Although the officer appeared to assume that the rear and rear passenger windows of all vehicles have to comply with the 35-percent transmission standard, that was an objectively unreasonable misinterpretation of Wis. Admin. Code. § Trans 305.32. And, it is undisputed that the officer did not observe any indicia that the windows in Bundy’s vehicle fell into the category of windows that are subject to the 35-percent transmission standard.
(¶ 24).