If you are arrested for driving under the influence of alcohol in Illinois, there are several defenses that you could pursue. If you did consume alcohol before getting behind the wheel, you may be able to mount an affirmative defense in certain situations. When a defendant in a criminal case mounts an affirmative defense, they introduce evidence that explains and mitigates their actions.
Common drunk driving defenses
Most defenses in drunk driving cases either challenge the validity of toxicology evidence or question the actions of the police officers involved. Breath test results may be excluded if the equipment used by law enforcement was not properly maintained and calibrated, and a blood test result could be challenged if the prosecutor cannot provide a complete chain of custody for the sample that was tested. DUI defenses that question the behavior of police officers usually challenge the legality of traffic stops. Police officers violate rights protected by the Fourth Amendment when they pull vehicles over without the requisite reasonable suspicion.
Affirmative DUI defenses
The most common affirmative DUI defenses are necessity and involuntary intoxication. A DUI defendant could mount an affirmative defense based on necessity if they drove while impaired to prevent greater harm. This could happen if a drunk driver gets behind the wheel to rush a badly injured person to an emergency room. A person becomes intoxicated involuntarily if they consume drugs or alcohol without knowing it. This often happens when drinks get mixed up at a party or gathering or food or drinks are “spiked” with drugs.
Proving guilt is not always easy in DUI cases
The penalties for driving under the influence are severe, but proving guilt beyond reasonable doubt can be challenging for prosecutors in DUI cases. DUI charges may be dismissed when toxicology tests were conducted improperly or with defective equipment. In some situations, drivers who get behind the wheel after drinking may mount affirmative defenses that explain their actions.