Weed DWI/DUI Lawyer St. Louis

What Is a Weed DWI or DUI in St. Louis?

In Missouri, you can be charged with a DWI (Driving While Intoxicated) for marijuana if an officer believes you’re impaired — even without any alcohol in your system. Unlike alcohol-related DWIs, there’s no legal limit for THC. That means it comes down to subjective signs like how you’re driving, how you speak, and how you perform on field sobriety tests.

Under Missouri Revised Statutes § 577.010, a person commits a DWI if they operate a motor vehicle while in an intoxicated or drugged condition. That includes marijuana, even if you bought, possessed, and consumed the marijuana legally. The law doesn't care how much THC is in your system, it only matters whether the officer thinks you were “under the influence” (i.e. "high") at the time.

Important: You can be arrested for a marijuana DWI in St. Louis even if you weren't high at the time. If an officer believes your ability to drive was impaired — or if you admit to recent cannabis use — that’s often enough for an arrest and charges.

Can You Get a DUI in St. Louis for Marijuana Use?

Yes — you can absolutely be charged with a DUI in St. Louis for marijuana, even if you’re not visibly “high” or don’t feel impaired. Missouri law focuses on whether your ability to safely operate a vehicle appears impaired due to drugs, and police officers have wide discretion to make that call.

Common reasons drivers are arrested for weed DWI include:

• Admitting recent marijuana use during a traffic stop
• Failing field sobriety tests
• Showing signs of confusion, bloodshot eyes, or slow reaction time
• Being evaluated by a Drug Recognition Expert (DRE)
• Testing positive for THC in blood or urine

Even if you’re a valid medical marijuana patient, that won’t automatically protect you. There’s no “legal limit” for cannabis, and prosecutors don’t have to prove a specific amount of THC — only that you were impaired while driving.

Free book

Don’t “Blow” Your DWI/DUI Case: Key Mistakes to Avoid

Combs Waterkotte, Missouri's leading DWI/DUI law firm, has handled over 10,000 cases successfully. This ebook guides you through the DWI/DUI defense process and helps you avoid key mistakes.

Name *

Email

Please leave this field empty. Submit Form

Δ

---

Read Book Online

How St. Louis Police Detect Marijuana DUI

Unlike alcohol, marijuana doesn’t show up on a breath test. That means St. Louis officers rely on more subjective tools to decide whether a driver is “under the influence.” If you’ve been pulled over and suspected of driving high, here’s how that process typically unfolds:

• Field Sobriety Tests: Officers may ask you to walk a straight line, balance, or follow a pen with your eyes. These tests are based on physical coordination and can be influenced by nerves, injury, or fatigue — not just drugs.
• Drug Recognition Experts (DREs): Some departments call in DRE-certified officers who claim to detect impairment based on pupil size, muscle tone, and divided attention tests. Their opinions are often challenged in court.
• Blood or Urine Testing: If you're arrested, police may seek a warrant to test for THC. But a positive test doesn’t prove you were impaired — marijuana can stay in your system for days or even weeks.
• Statements or Odor: Admitting recent use or having the smell of cannabis in the vehicle can give police probable cause to arrest or search further.

The bottom line: Missouri police don’t need a scientific threshold to charge you. All it takes is their judgment — and our job is to challenge every assumption they made along the way.

Defenses to Marijuana DWI Charges in St. Louis

In Missouri, defending against a marijuana-related DWI (Driving While Intoxicated) charge requires a nuanced and strategic legal approach. Unlike alcohol-related DWIs, which are based on blood alcohol concentration (BAC), marijuana DWI cases often hinge on subjective indicators, officer observations, and questionable testing procedures. Our St. Louis weed DWI attorneys use a variety of targeted defenses depending on the facts of your case:

1. Challenging the Traffic Stop

• Unlawful Stop: If there was no clear traffic violation or reasonable suspicion, any evidence collected afterward — including sobriety tests or statements — could be suppressed.
• Profiling or Pretextual Stops: If you were pulled over without valid cause, the legality of the entire arrest may be in question.

2. Faulty Field Sobriety Tests (FSTs)

• Unlike alcohol cases, there’s no scientifically accepted field test for marijuana intoxication. Many FSTs used in weed DWI stops are non-standardized and highly subjective.
• Medical conditions, injuries, or anxiety can affect performance — and don’t prove impairment.

3. Drug Recognition “Expert” (DRE) Flaws

• DRE assessments are based on opinion, not hard science. Their conclusions can be challenged in court.
• We cross-examine DREs on their training, methods, and assumptions — often revealing inconsistencies or bias.

4. Blood or Urine Testing Problems

• THC levels don’t equal impairment. You can test positive days after use — long after the effects have worn off.
• We challenge tests based on residual presence, lab errors, or improper collection procedures.

5. No Evidence of Actual Impairment

• Marijuana DWI cases require proof you were impaired while driving — not just that THC was in your system.
• We highlight clear driving behavior, lucid speech, calm demeanor, and coherent responses from the bodycam and dashcam videos to undermine the prosecution’s theory.

6. Procedural and Constitutional Violations

• Miranda violations, improper searches, or illegal arrests can result in evidence suppression.
• Our team scrutinizes every step of the police interaction for mistakes.

7. Independent Video or Witness Testimony

• Dashcam footage or passenger testimony that contradicts officer claims can tip the balance in your favor.

If you’re facing weed DWI charges in St. Louis, the stakes are high — but so are the opportunities to fight back. At Combs Waterkotte, we use every available tool to challenge the evidence, protect your rights, and work toward the best possible outcome.

Can You Refuse a Marijuana Drug Test in Missouri?

Under Missouri’s implied consent law, if you’re lawfully arrested on suspicion of DWI — including for marijuana — you’re considered to have consented to chemical testing of your breath, blood, or urine. Refusing the test is legal, but it may come with consequences.

What Happens If You Refuse a Drug Test?

• Automatic license revocation: Refusing a blood or urine test results in a one-year license revocation under Missouri law — separate from any criminal DWI case. However, you have a right to request an administrative hearing within 15 days to challenge the suspension court. Our St. Louis weed DWI/DUI lawyers can fight for you to keep your license at the administrative hearing.
• Admissible in court: Your refusal can be introduced as evidence of guilt at trial.
• No protection from prosecution: Even without a test, you can still be charged and convicted based on officer observations or other evidence.

Should I Refuse a Drug Test for a Weed DWI?

Our weed DWI/DUI lawyers in St. Louis always recommend refusing all field and chemical tests until police acquire a warrant. By submitting to the tests, all you're doing is giving the state more evidence to use against you. Give the police as little evidence as possible, and let us do the heavy lifting from there.

Can You Be Forced to Give a Sample?

In most cases, officers must obtain a warrant to draw blood without consent. But under certain conditions — like serious injury or a fatal crash — Missouri law allows for a nonconsensual blood draw without a warrant. These cases can be challenged on constitutional grounds.