---
title: "What are the specific grounds for suppressing evidence in an Illinois DUI?"
description: "Illinois suppression motions in DUI cases attack constitutional and statutory foundation. Fourth Amendment challenges target stops made without reasonable suspicion and arrests made without probable..."
url: https://chicagoduilawyer.net/faq-items/what-are-the-specific-grounds-for-suppressing-evidence-in-an-illinois-dui/
date: 2026-07-08
modified: 2026-07-08
author: "Chicago DUI Lawyer"
type: faq
lang: en
---

# What are the specific grounds for suppressing evidence in an Illinois DUI?

Illinois suppression motions in DUI cases attack constitutional and statutory foundation. Fourth Amendment challenges target stops made without reasonable suspicion and arrests made without probable cause. Fifth Amendment issues arise when Miranda warnings are missing after custody attaches. Statutory grounds under 625 ILCS 5/11-501.2 include breath machine certification gaps, expired operator licenses, observation-period failures, and warrantless blood draws outside recognized exceptions. Chain of custody breaks suppress blood and urine results. A Chicago DUI lawyer files targeted motions supported by discovery, calibration logs, and video. If the motion is granted, the state often cannot proceed and the case gets dismissed or reduced on the courthouse steps.