Chicago’s DUI enforcement is active, aggressive, and often unpredictable. Officers conduct patrols near Wrigley Field, The West Loop, River North, Hyde Park, and the entire Lake Shore Drive corridor. DUI arrests occur on quiet residential streets, expressway interchanges, and late-night entertainment areas where police maintain constant visibility. Under 625 ILCS 5/11-501, Illinois treats driving under the influence as a misdemeanor for first offenders, but certain situations escalate the charge to an aggravated felony.

Even though Chicago police receive training on how to conduct DUI investigations, many arrests end up shaped—and weakened—by preventable mistakes. Officers may misinterpret nervous behavior as impairment, skip mandatory steps during testing, forget to activate body-worn cameras, or record observations that video evidence later contradicts. While some defendants assume “the officer’s word is enough to convict,” the reality is very different once the case reaches the courtroom. Judges expect officers to follow Illinois law, constitutional protections, and standardized DUI protocols. When they don’t, the state’s case begins to lose its foundation.

As a Chicago DUI attorney with decades of courtroom experience, I routinely see how police mistakes open the door to strong defenses. What starts as a seemingly overwhelming case can become entirely different after the evidence is carefully reviewed. Small errors create reasonable doubt, procedural violations lead to suppressed evidence, and inconsistencies in reports damage officer credibility. These mistakes do not excuse impaired driving—but they absolutely matter for defendants who were wrongfully accused or unfairly charged.