Blood alcohol tests are often treated as strong evidence in Illinois DUI cases, but they aren’t as foolproof as you’d think. Errors in testing, handling, and storage can all affect the accuracy of the results. If you’re facing DUI charges based on a blood test in 2026, our Chicago DUI defense lawyer can help you understand whether the results in your case can actually be trusted.
How Does Blood Alcohol Testing Work in Illinois DUI Cases?
When someone is arrested for DUI in Illinois, police may request a blood test to measure blood alcohol concentration (BAC). Under 625 ILCS 5/11-501.2, Illinois law sets rules for how chemical tests, including blood tests, must be administered and how the results can be used in court.
A blood sample is typically drawn at a hospital or by a trained professional, then sent to a lab for analysis. The lab measures the amount of alcohol in the blood and reports this as a percentage. In Illinois, a BAC of 0.08 percent or higher is considered legally intoxicated for most drivers.