McMahon Law Offices
Facing a DUI charge in DuPage County? Get a former prosecutor who knows how the state builds DUI cases and how to beat them. Call for a free case review.
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"I prosecuted DUI cases for years. I know exactly how the state builds these cases, what evidence they rely on, and where every one of them is vulnerable."
— Mike McMahon, Former DuPage County ProsecutorDUI Defense Overview
A DUI charge in DuPage County is not just a traffic ticket. It is a criminal case that can cost you your license, your job, and your freedom.
McMahon Law Offices has defended over a thousand DUI cases in DuPage County. We handle first-time DUI, aggravated DUI, felony DUI, breathalyzer refusals, drug DUI, and every charge under 625 ILCS 5/11-501.
Mike McMahon spent years as a DuPage County prosecutor building DUI cases against defendants. He knows how officers are trained to build probable cause, how the state presents breath and blood evidence, and what weaknesses they hope defense attorneys never find.
We fight to get DUI charges dismissed, reduced, or beaten at trial. We challenge traffic stops, field sobriety tests, chemical testing procedures, and every piece of evidence the prosecution uses against you.
Illinois DUI Charges
| Charge | Classification | |
|---|---|---|
DUI Over 0.08 BAC Operating a vehicle with a blood alcohol concentration at or above the legal limit. 625 ILCS 5/11-501(a)(1) |
Class A Misdemeanor | |
DUI Under the Influence of Alcohol Charged based on officer observation of impairment, even without a breath test. 625 ILCS 5/11-501(a)(2) |
Class A Misdemeanor | |
DUI Drugs or Prescription Medication Driving while impaired by cannabis, controlled substances, or even prescribed medication. 625 ILCS 5/11-501(a)(4) |
Class A Misdemeanor | |
DUI Cannabis / THC Per se THC limit in blood while driving. Cannabis is legal in Illinois, but driving impaired is not. 625 ILCS 5/11-501(a)(7) |
Class A Misdemeanor | |
DUI with High BAC (0.16+) Enhanced mandatory penalties including community service and higher fines. 625 ILCS 5/11-501 |
Enhanced Misdemeanor | |
Aggravated DUI (Felony) Elevated to felony for 3rd+ offense, injury, child passenger, no license, or school zone. 625 ILCS 5/11-501(d) |
Class 4 to Class X Felony | |
Statutory Summary Suspension Automatic license suspension triggered by failing or refusing a chemical test. 625 ILCS 5/11-501.1 |
Administrative Penalty | |
DUI with Minor Passenger Enhanced penalties and potential felony charges when a child under 16 is in the vehicle. 625 ILCS 5/11-501(d)(1)(J) |
Aggravated Felony | |
Underage DUI (Zero Tolerance) Any detectable alcohol for drivers under 21. Zero tolerance suspension and criminal charges. 625 ILCS 5/11-501.8 |
Class A Misdemeanor | |
Second DUI Offense Mandatory minimum 5 days jail or 240 hours community service. No court supervision available. 625 ILCS 5/11-501 |
Class A Misdemeanor | |
Third DUI Offense (Felony) Automatic Class 2 felony. 3 to 7 years in prison and mandatory 10-year license revocation. 625 ILCS 5/11-501(d)(1)(A) |
Class 2 Felony | |
DUI Causing Bodily Harm DUI resulting in injury to another person. Elevated to aggravated DUI with enhanced prison time. 625 ILCS 5/11-501(d)(1)(C) |
Class 4 Felony | |
DUI with No Valid License Driving under the influence without a valid or suspended/revoked license. Automatic felony upgrade. 625 ILCS 5/11-501(d)(1)(H) |
Class 4 Felony | |
DUI in a School Zone DUI committed in a school zone or on school property. Enhanced sentencing and mandatory minimums. 625 ILCS 5/11-501(d)(1)(I) |
Class 4 Felony | |
Breathalyzer / Chemical Test Refusal Refusing a breath, blood, or urine test triggers a 12-month statutory summary suspension for first offense. 625 ILCS 5/11-501.1 |
Administrative Penalty |
DUI Case Results
Every result below is a real DUI case handled in DuPage County.
Why McMahon Law Offices
Former prosecutors who built DUI cases now use that knowledge to tear them apart.
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Mike McMahon built DUI cases for the state. He knows how officers are trained, what evidence the prosecution relies on, and where their case falls apart.
Breathalyzer calibration, blood draw procedures, field sobriety administration. We challenge every piece of evidence the state uses against you.
Judge Pierce spent years on the bench in DuPage County. He knows what arguments resonate with every judge hearing DUI cases in Wheaton.
We fight statutory summary suspensions, file hearing requests within the 90-day deadline, and pursue every option to keep you driving legally.
DUI arrests happen at 2 AM, not 2 PM. Call us anytime. Nights, weekends, holidays. We answer.
We prepare every DUI case as if it is going to trial. DuPage County prosecutors know this, and that reputation gets better plea offers before trial.
How To Get Started
A simple, straightforward process from your first call to your first court appearance.
Call us or fill out our contact form. The sooner we start, the more options you have. Your 90-day license suspension deadline is already running.
Tell us everything about the stop, the arrest, the tests, and the charges. We need every detail to find the weaknesses in the state's case.
We review police reports, dashcam footage, breathalyzer maintenance records, and every piece of evidence. We file motions and challenge the state's case.
Dismissal, reduced charges, not guilty verdict, or the most favorable resolution possible. We handle everything so you can get back to your life.
Your DUI Defense Team
A former prosecutor who built DUI cases and a retired judge who decided them.
Areas We Serve
We defend DUI charges throughout DuPage County and neighboring Illinois counties.
2150 McDonald Dr Suite 1608
Oak Brook, IL 60523
Available for in-person case reviews upon request. We defend DUI cases in all of DuPage County and neighboring counties throughout Illinois.
Do not make any statements to police beyond your name and basic identifying information. Do not consent to additional searches. Call an attorney immediately. You have 90 days from your arrest to challenge your statutory summary suspension, and your first court date is almost always scheduled after that deadline. The earlier you call, the more options we have to protect your license and your record.
Yes. DUI charges are dismissed regularly when the traffic stop lacked reasonable suspicion, when field sobriety tests were improperly administered, when the breathalyzer was not properly calibrated or maintained, or when blood draws violated proper procedures. Every DUI case has potential vulnerabilities. Our job is to find them.
If you fail a chemical test (BAC of 0.08 or higher), your license is automatically suspended for 6 months on a first offense. If you refuse the test, the suspension is 12 months. This is called a statutory summary suspension and it is separate from your criminal case. You have 90 days to petition the court to rescind the suspension. A monitoring device driving permit (MDDP) may allow you to drive during the suspension with a breath alcohol ignition interlock device.
A first DUI in Illinois is a Class A misdemeanor carrying up to 364 days in jail and fines up to $2,500. You also face a 6 to 12 month license suspension, mandatory alcohol evaluation, and possible community service. First-time offenders may be eligible for court supervision, which avoids a conviction on your record if you complete all requirements. A BAC of 0.16 or higher triggers enhanced mandatory minimums including 100 hours of community service.
A first or second DUI in Illinois is typically a Class A misdemeanor. A third DUI is automatically a Class 2 felony carrying 3 to 7 years in prison. A DUI can also be elevated to a felony on a first or second offense if it involves a crash causing great bodily harm, driving without a valid license, no insurance, a child passenger under 16, or driving in a school zone. Felony DUI carries mandatory prison time and license revocation.
There is no simple answer. Refusing the breathalyzer triggers a 12-month license suspension (versus 6 months for failing). However, it also means the state has less direct evidence of your BAC. Each situation is different. What matters most is that you call an attorney immediately after your arrest so we can evaluate your specific circumstances and advise you on next steps.
Most first-offense DUI cases in DuPage County resolve within 3 to 6 months. Cases involving felony charges, accidents, or contested evidence can take 6 to 12 months or longer. If the case goes to trial, add additional time for jury selection and proceedings. We give you a realistic timeline at your free consultation based on your specific charges and circumstances.
No. DUI convictions in Illinois cannot be expunged or sealed. This is one of the most important reasons to fight a DUI charge aggressively from the start. If your case is dismissed or you are found not guilty, the arrest record may be eligible for expungement. If you receive court supervision (not a conviction), the record may be eligible for expungement after a waiting period. Avoiding a conviction is always the best outcome.
Resources
Guides written to help you understand your DUI charges, rights, and options.
Get Started
Submit a contact form or call us to schedule your free DUI case review. Your 90-day license deadline is already running.
Your information is confidential and protected by attorney-client privilege. We will never share your information.
