This is a common question. It is directly related to the presumptive legal limit of .08 blood alcohol concentration. Section 625 ILCS 5/11-50(a)(1) of the Illinois traffic code states that any person with an alcohol concentration in their blood or breath above 0.08 is guilty of Driving Under the Influence. Section 625 ILCS 5/11-50(a)(2) simply states that if a person is "under the influence of alcohol" he or she is guilty of Driving Under the Influence. If you are charged under both these sections, we can assume you took the "breathalyzer." The State, however, can try to prove you guilty two ways: (1) that your blood or breath alcohol concentration was at or over .08 — in which case there is a presumption that you are under the influence; or (2) that you were under the influence. For the second proposition the State must offer other evidence to show you were under the influence — such as bad driving, poor field sobriety test, or erratic behavior. The second section is obviously harder for the State to prove, which is why in many cases it is better not to have taken a blood or breath test.
© 2019 Casey Nelson LLP