Here’s What Really Happens
Cannabis may be legal in Illinois, but that doesn’t mean you can drive high. Law enforcement across Chicago and the state has cracked down hard on cannabis-impaired driving since legalization took effect in 2020. And make no mistake—being charged with a marijuana DUI is not a slap on the wrist. It’s a serious crime under Illinois law, and it can change the course of your life.
If you’ve been accused of driving under the influence of cannabis in Illinois, you probably have questions: Can they actually prove I was impaired? What if I used marijuana hours ago? Will I lose my license? Do I need a lawyer?
Let’s break down what actually happens in these cases—from the moment you’re pulled over to what it means to be convicted under Illinois criminal law.
Legal Cannabis, Illegal Driving: What the Law Really Says
Under 625 ILCS 5/11-501, Illinois makes it illegal to drive or be in “actual physical control” of a motor vehicle while under the influence of alcohol, drugs, or any combination. This includes cannabis, whether it was smoked, vaped, eaten, or used medicinally.
The law allows for two ways to prosecute:
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Impairment Standard: Police testify that you were too impaired to drive safely based on their observations and your behavior.
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Per Se Standard: Prosecutors claim your THC level exceeded the legal threshold—5 nanograms per milliliter of whole blood or 10 nanograms per milliliter of another bodily substance within two hours of driving.
Here’s where things get complicated. Unlike alcohol, THC doesn’t pass through the body quickly. It can linger in your system for days, even weeks. That means you could test over the legal limit without being high at all when pulled over.
This disconnect is one reason marijuana DUI charges are so aggressively contested—and why many result in dismissal or acquittal when properly defended.
The Typical Scenario: How a Marijuana DUI Begins
It usually starts with a simple traffic stop. You’re pulled over for speeding, forgetting a turn signal, or a broken taillight. Once the officer approaches your window, the situation can escalate fast if they smell cannabis or believe you appear “out of it.”
The officer may ask whether you’ve used marijuana. If you admit to using it—even hours earlier—you’ve just helped build their case. You may be asked to perform field sobriety tests. If you show signs of poor balance, lack of coordination, or confusion, the officer may decide to arrest you for DUI.
After the arrest, police will ask for a chemical test—typically a blood or urine sample. Refusing the test doesn’t mean you walk away. It triggers an automatic statutory summary suspension of your driver’s license under 625 ILCS 5/11-501.1.
Charged with DUI of Cannabis: What the State Must Prove
To convict you of a marijuana DUI, prosecutors must establish one of two things:
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That you were actually impaired by cannabis while driving, based on officer testimony, field sobriety tests, or other evidence.
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That your THC level exceeded the legal limit, confirmed by a lab test, and the test was performed within the legal two-hour window.
But there are gaps and weaknesses in these cases. Field sobriety tests are notoriously unreliable for cannabis. And even if a blood test shows THC above the limit, that doesn’t automatically mean you were impaired.
Prosecutors must also prove that police followed proper procedures. Did they have legal grounds for the traffic stop? Was the arrest based on probable cause? Was the chemical test administered correctly and on time? Any mistake or rights violation may render the evidence inadmissible.
Consequences of a Marijuana DUI Conviction in Illinois
Being convicted of a cannabis DUI in Illinois is more than a traffic ticket—it’s a criminal record that can follow you for life. For a first offense, you’re looking at a Class A misdemeanor that carries:
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Up to one year in jail
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Fines of up to $2,500
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Mandatory drug treatment or education
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License revocation for one year
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Court costs, probation fees, and increased insurance rates
If you have a prior DUI, the penalties increase substantially. A second DUI within five years brings mandatory jail time or community service, and your license may be revoked for five years.
A third DUI offense is usually a Class 2 felony, which means potential prison time of 3 to 7 years and license revocation for 10 years. Felony charges may also apply if:
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You were involved in an accident causing injury
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A child under 16 was in the car
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You were driving on a suspended or revoked license
Even after serving any sentence, you may need to attend hearings with the Secretary of State, install a Breath Alcohol Ignition Interlock Device (BAIID), or participate in monitoring programs to regain driving privileges.
Why Fighting a Marijuana DUI Is Worth It
Many people think their only option is to plead guilty and move on. But the truth is, cannabis DUI cases are among the most defensible criminal charges. The science is not on the prosecutor’s side. Field sobriety tests? Subjective. Blood test? May not reflect current impairment. Officer observations? Can be biased or inaccurate.
That’s why our team pushes hard at every stage. We challenge the traffic stop, the arrest, the test, and the testimony. We use toxicologists, motion hearings, and forensic review to expose weaknesses in the case. And when necessary, we take the case to trial.
Case Example: Acquittal for Client Accused of High Driving After Party
One of our clients was pulled over in suburban Cook County after allegedly swerving lanes on the expressway. The officer said he smelled cannabis and noted bloodshot eyes. Our client admitted to using marijuana the day before. A blood test showed 4.7 nanograms of THC—not quite over the legal limit but close.
We filed motions to suppress the stop and the arrest. At trial, we presented a toxicologist who explained that THC at that level is consistent with past use—not active intoxication. We also raised questions about the officer’s training and the field sobriety test administration. The judge returned a not guilty verdict, citing insufficient evidence of impairment.
Don’t Make These Mistakes If You’ve Been Arrested
Many people dig a deeper hole after a marijuana DUI arrest. Don’t make these common errors:
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Admitting to recent use: You don’t have to answer that question. It may hurt your case later.
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Assuming the blood test seals your fate: THC levels are not reliable indicators of impairment.
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Delaying in hiring an attorney: Evidence disappears fast, and deadlines for license hearings are tight.
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Relying on a public defender if you want personalized, in-depth defense attention.
You Need a Criminal Defense Lawyer Who Understands Marijuana DUI Law
At The Law Offices of David L. Freidberg, we’ve spent decades defending clients in Chicago and surrounding counties. We understand both sides of the courtroom—how prosecutors think and how judges rule. We stay on top of the latest case law, testing standards, and defense strategies.
We take the time to explain your options, protect your rights, and give you an aggressive defense. Our goal is to keep you out of jail, preserve your license, and avoid a permanent record whenever possible.
We Serve Clients Across Chicago and Northern Illinois
Our office handles cannabis DUI cases in:
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Chicago (Cook County)
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DuPage County (Naperville, Wheaton, Elmhurst)
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Lake County (Waukegan, Mundelein)
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Will County (Joliet, Bolingbrook, Plainfield)
We’ve appeared before dozens of judges and understand the courtroom dynamics in each venue.
Call for a Free Consultation 24/7
If you’ve been arrested for DUI of marijuana in Illinois, don’t wait to act. Time is critical—your license could be suspended even before your first court date.
Whether you’re charged in downtown Chicago, Skokie, Maywood, Bridgeview, or Rolling Meadows, we’re ready. We appear regularly in courtrooms throughout Cook, DuPage, Will, and Lake Counties. And we don’t treat aggravated speeding as just another moving violation.
If you were arrested in Chicago, protect your future by contacting The Law Offices of David L. Freidberg. We have decades of experience handling DUI cases in Illinois. Our firm is available 24/7 to provide the legal defense you deserve.
Contact us today at (312) 560-7100 or toll-free at (800) 803-1442 for a free consultation. We’re available 24/7 to serve clients throughout Illinois, Cook County, DuPage County, Will County, and Lake County.