When Does a DUI Become an Aggravated DUI in Illinois?

 Posted on July 10, 2025 in DUI

Most charges for driving under the influence (DUI) are misdemeanors, but any element that classifies it as a felony turns it into an aggravated DUI charge. Under Illinois law, an aggravated DUI can be charged as anything from a Class 4 felony up to the most serious charge, a Class X felony. If you have questions about the charges you face, a Wheaton, IL DUI defense attorney can help.

What Is a Class 4 Felony DUI in Illinois?

In Illinois, a DUI becomes a Class 4 felony under specific circumstances, elevating it from a misdemeanor to a serious criminal offense. Although a Class 4 felony is the least serious felony classification, it can still carry harsh penalties. A conviction can result in up to three years in prison and a substantial fine, according to Section 4.5-45 of  730 ILCS 5/5. For example, a Class 4 felony DUI may result from a drunk driving car accident involving an injured child under 16 or a DUI while driving a school bus with a child on board. If you were driving under the influence when an accident occurred and someone suffered a serious injury, disfigurement, or permanent disability, you could face an aggravated DUI charge.

What Are the Most Serious DUI Charges in Illinois?

Illinois categorizes felony DUI charges based on severity, prior offenses, and aggravating circumstances. Beyond Class 4 felonies, DUIs may rise to higher felony levels with significantly harsher penalties:

• Class 3 felonies: A DUI becomes a Class 3 felony if you have a prior conviction for reckless homicide involving a DUI or an aggravated DUI involving death. Under 730 ILCS 5/5-4.5-40, a Class 3 felony can carry sentences of two to five years in prison and up to $25,000 in fines.

• Class 2 felonies: Class 2 felony DUIs include offenses such as a second DUI conviction involving bodily harm to a child passenger under 16, a third or subsequent DUI conviction, or a DUI resulting in death. Under 730 ILCS 5/5-4.5-35, penalties range from three to seven years in prison and a potential $25,000 fine.

• Class 1 felonies: A fifth DUI conviction elevates the charge to a Class 1 felony, punishable by four to 15 years in prison and a $25,000 fine, according to 730 ILCS 5/5-4.5-30.

• Class X felonies: The most severe DUI offense in Illinois is a Class X felony, typically charged for a sixth or subsequent DUI conviction. A Class X felony carries a mandatory prison term of six to 30 years and fines of up to $25,000, governed by 730 ILCS 5/5-4.5-25.

How Do You Fight a Felony DUI Charge in Illinois?

The potential defenses for aggravated DUI vary based on the specific charges you face and the details of your arrest. Your attorney may challenge the legality of the traffic stop or dispute the accuracy of breath or blood tests. They may question whether proper procedures were followed during the arrest and testing. The validity of field sobriety tests and chemical tests can be questioned, and your attorney may be able to negotiate for reduced charges or alternative sentencing under certain circumstances.

Contact a Wheaton, IL Aggravated DUI Defense Attorney Today

If you are facing felony DUI charges, you should not attempt to navigate the legal system alone. The experienced DuPage County, IL DUI defense lawyer at Davi Law Group, LLC will analyze the details of your case and fight for your rights. Call 630-580-6373 today to schedule your free consultation.