An Illinois motorist walked away from a drunk driving conviction last week after the state's second highest court rejected the police account of events. Amy Lynn Mueller had been passing through McHenry County on US Route 12 on February 11, 2017, when her Jeep drew the attention of sheriff's deputy Trent Raupp.

She turned left (after signaling) onto Illinois Route 31, and the deputy followed. On a dark, twisty stretch of road, her tires briefly grazed the inside and outside lines of her lane over the course of a mile without ever crossing over the line. The deputy thought the three instances of touching the lane lines constituted illegal lane usage, so he ordered her to pull over. That led to her arrest for driving under the influence of alcohol (DUI), but that charge could not stick if the initial reason for the traffic stop turned out to be illegal. On this score, the trial judge found Deputy Raupp's testimony "problematic," especially since he did nothing to fix his dashcam which had been out of commission for four months prior to this stop.

"He either didn't remember important details or was flippant with [defendant's] attorney," McHenry County Circuit Court Judge Joel D. Berg explained. "In any event, Deputy Raupp never saw the Jeep's tires cross over either the yellow center line or the white fog line, nor did he observe any jerky or erratic driving corrections. The three lane-line touches occurred over a mile-long twisting and turning stretch of road."

Under the Illinois lane usage law, a car shall be driven "as nearly as practicable entirely within a single lane" until it is ready to move safely into another after a signal. The appellate judges pointed out that the courts have only held it a crime to cross over the lane lines. They supported the trial judge's observations.

"We conclude that the statute is unambiguous," Judge Robert D. McLaren wrote for the appellate panel. "Moreover, the meaning of the statute was or should have been within Raupp's knowledge; he was on notice of the rules of the road. Therefore, Heien and Gaytan do not apply and the stop cannot be validated as based on a reasonable mistake of law."

Weaving within a lane without an "obvious" reason could be worth investigating, the judges noted, but three brief touches of the lane line on a twisty road is not unusual.

A copy of the ruling is available in a PDF file at the source link below.