Knowledgeable O’Fallon, MO DUI And DWI Lawyers
Last updated on March 12, 2026
When police suspect alcohol or drugs affected your driving, you may be charged in Missouri with driving while intoxicated (DWI), sometimes referred to as DUI. A DWI arrest can move quickly, and what happens early in the process can affect your options later. Even a first offense can create serious stress and uncertainty about what comes next.
A conviction can affect far more than your next court date. Depending on the situation, you may be facing the possibility of jail, significant fines, higher insurance costs and a lasting mark on your record. You may also be dealing with separate actions that impact your ability to drive, which can create immediate problems for work, school and family responsibilities.
At Suddarth & Koor, LLC, we bring nearly 40 years of combined experience to defending people in O’Fallon and throughout St. Charles County. Call 636-260-0132 or message us for a free consultation. In addition to DWI defense, our firm also handles broader criminal law matters.
On this page:
What Are The Penalties Of A DWI In Missouri?
Missouri treats DWI allegations seriously, and the consequences can extend well beyond a single court date. In many cases, you may be facing two tracks at the same time: a criminal case in court and an administrative action that affects your driver’s license.
The ranges below provide a snapshot of how penalties may increase for a first, second or third offense.
| Type of penalty | First offense | Second offense (within five years) | Third offense |
|---|---|---|---|
| Charge level | Class B misdemeanor | Repeat offender (Class A misdemeanor) | Persistent offender (Class E felony) |
| Fine | Up to $1,000 | Up to $2,000 | Up to $10,000 |
| Jail sentence | Up to six months (or two years probation) | 10 days minimum, up to 12 months | 30 days to four years |
| Community service | — | 30 days | 60 days |
| License suspension/revocation (administrative) | 90-day suspension | Five-year revocation | 10-year revocation |
| Ignition interlock device (IID) | Possible (discretionary) | Mandatory for repeat offenders | Mandatory for repeat offenders |
BAC-related minimum jail requirements: If your BAC is .15% to under .20%, you must serve 48 hours in jail. If it is .20% or greater, you will serve at least five days in jail.
Refusing a chemical test: Missouri’s implied consent law generally means that after a DWI arrest, you are expected to submit to a chemical test (such as breath, blood, saliva or urine). If you refuse, you can face an immediate one-year driver’s license revocation separate from the criminal case. In addition, the refusal may be used as evidence against you in court. A refusal can also add steps you must complete before you can get back on the road, including completing the Substance Awareness Traffic Offender Program (SATOP) and retesting.
Two Cases After A DWI Arrest: Your License And The Criminal Charge
After a DWI arrest, you are often dealing with two separate tracks at the same time: the court case and the driver’s license case. The criminal prosecution can lead to penalties such as fines, probation or jail time, and it can leave you with a permanent record. Separately, there may be a process that impacts whether you can legally keep driving while the case is pending.
Both tracks move on their own timelines, and what happens in one does not automatically resolve the other. We help clients address both strategically, with the goal of minimizing immediate damage and fighting for the best long-term outcome.
Administrative (License) Action: Deadlines, Hearings And Driving Privileges
You may have a limited amount of time (often as little as 15 days) to request an administrative hearing to challenge the suspension or revocation of your license. If you miss that window, you may lose an important chance to contest the action and protect your driving privileges.
Many DWI-related cases require completion of SATOP (the Substance Awareness Traffic Offender Program). SATOP typically involves screening/assessment and education or treatment, and completion may be necessary before your license is eligible for reinstatement.
Criminal Prosecution: Court Hearings And Case Strategy
In the criminal case, we focus on the evidence the state plans to use, including the reason for the stop, the officer’s observations, field sobriety testing and chemical test procedures. Depending on the circumstances, the defense may involve challenging how evidence was collected, negotiating for a reduction, or preparing to litigate the charge in court.
Building A Case Against DWI/DUI Charges
A DWI charge can feel like it is based on a single test result or an officer’s conclusion, but these cases are often built from many small pieces of information. That means the details matter. A strong defense starts with a careful review of what happened before, during and after the stop, including whether proper procedures were followed at every step.
Our approach is to dig into the evidence early, identify weaknesses, and build a strategy that matches your goals. In some cases, that may mean challenging the legality of the stop or the reliability of testing. In others, it may involve presenting mitigating information and negotiating for a reduction that helps you avoid long-term consequences.
Common DWI Defense Strategies
Depending on the circumstances, defenses may focus on issues such as:
- The traffic stop: Whether police had a lawful reason to stop you in the first place
- Officer observations: Whether conclusions about impairment are supported by the facts
- Field sobriety tests: Whether the tests were administered correctly and whether medical conditions, fatigue, weather or footing affected results
- Breath testing: Calibration, maintenance, operator error, timing and other reliability issues
- Blood/urine testing: Chain of custody, lab methods and whether results reflect impairment at the time of driving
- Constitutional issues: Unlawful searches, interrogation problems and other rights concerns
- Negotiation and mitigation: When appropriate, seeking reduced charges/penalties and building a plan to limit fallout (including other traffic matters like speeding tickets)
Just as important, we also look at any facts the prosecution may point to as aggravating circumstances. These details can influence how the case is charged, what penalties are on the table and how the court views the allegations.
Factors That Can Increase Penalties
Even when the charge is a first offense, the allegations can be treated more seriously depending on what the state claims happened. Understanding these aggravating factors early helps guide decisions about how to fight the charge and how to protect your license.
Certain factors can increase exposure even on a first offense, including:
- An alleged BAC of .15% or higher
- Having a passenger under the age of 17
- An accident causing injury or death
- Underage driving allegations
- Driving with a suspended or revoked license
- Commercial-driver allegations (which may involve different BAC standards)
Our objective is to pursue dismissal or reduction when possible and to help you avoid a result that follows you for years. When you contact us, we can talk through what happened, what deadlines you may be facing, and the next steps for both the court case and your driving privileges.
Contact Us Now For A Free DWI Defense Consultation
At Suddarth & Koor, LLC, we stand ready to help you if you are facing a DWI charge. We can review the circumstances of your arrest, explain what you are up against on both the criminal and license sides of the case, and help you understand the options available for defending your record and your driving privileges.
Call 636-260-0132 or message us for a free consultation about your case. The sooner you reach out, the sooner we can start preserving key details and helping you meet any time-sensitive deadlines.