Illinois blood evidence gets challenged on constitutional grounds, statutory foundation, and scientific reliability. Constitutional attacks target warrantless draws under McNeely. Statutory challenges under 625 ILCS 5/11-501.2 require proper preservatives, proper site preparation without alcohol swabs, qualified personnel, and chain-of-custody documentation. Scientific attacks target fermentation from insufficient sodium fluoride, hemolysis, contamination, and misidentification. Serum-to-whole-blood conversion errors overstate BAC. Retesting rights under Illinois law preserve independent analysis of the sample. Time between driving and draw affects retrograde extrapolation calculations. A Chicago DUI lawyer sequences motions to suppress, motions in limine, and expert testimony to attack the state's blood result at every layer before trial.
