Many people in Missouri know the legal blood alcohol concentration (BAC) limit is 0.08%. It is often assumed that if you stay under that number, you cannot be arrested. Unfortunately, that is not true. Missouri law allows you to be charged and even convicted of driving while intoxicated (DWI) with a BAC below 0.08%. This is because the law focuses on whether your driving ability was impaired, not just the number on a breath test. If an officer believes alcohol, prescription medication, or drugs affected your ability to drive safely, you can still be facing a serious charge. Understanding how and why this happens can make a big difference in protecting your future.

How Missouri Defines DWI

Under Missouri Revised Statutes § 577.010, you commit DWI if you operate a motor vehicle while “in an intoxicated condition.” The law does not require a BAC of 0.08% or higher. There are two ways you can be charged:

• Per Se DWI – A BAC of 0.08% or above. The number itself is enough for the state to prosecute, even if you appear sober.
• Impairment-Based DWI – A BAC below 0.08%, but the officer believes you were impaired based on how you were driving, your behavior, or other evidence.

The second type of charge is the one that catches many drivers off guard. You might think a 0.06% or 0.07% result proves you are in the clear. The officer may see it differently.

What Officers Look for Below the Legal Limit

If your BAC is under 0.08%, the arrest decision often comes down to the officer’s observations. They may claim to have seen signs such as:

• Slurred or slow speech
• Bloodshot or watery eyes
• Unsteady balance or stumbling
• Confusion or trouble following directions
• Difficulty finding or handling your license and registration
• Struggling with roadside sobriety tests

The problem with these signs is that they can be caused by many things other than alcohol. Fatigue, stress, allergies, or medical conditions can produce similar symptoms. Even so, these observations are often used to justify an arrest.

Why Some People Feel Impaired at Lower BAC Levels

Not everyone reacts to alcohol in the same way. You might feel perfectly fine after two drinks, while someone else feels lightheaded or sluggish after one. Factors that influence how alcohol affects you include:

• Body size and weight
• Metabolism speed
• Food consumed before or during drinking
• Alcohol tolerance
• Mixing alcohol with medications

Because of these differences, an officer may believe you were impaired even though your BAC is under the legal limit.

DWIs Involving Prescription or Over-the-Counter Medications

Missouri law treats impairment from prescription drugs the same as alcohol impairment. Even medications you are legally allowed to take can lead to a DWI charge if they affect your ability to drive safely. Examples include:

• Anti-anxiety medications like Xanax
• Prescription sleep aids such as Ambien
• Strong painkillers
• Cold or allergy medicines that cause drowsiness

In these cases, there may be no BAC reading at all. Instead, the charge is based on driving behavior, physical symptoms, and sometimes the opinion of a Drug Recognition Expert (DRE).

Consequences of a Low-BAC DWI

A DWI charge under 0.08% can still result in serious penalties. Depending on the facts of your case, you could face:

• Significant fines
• Suspension or revocation of your driver’s license
• Mandatory alcohol or drug education programs
• Higher car insurance premiums
• Jail time

If there were aggravating factors—such as a minor in the car, an accident, or prior offenses—the penalties can be even harsher.

Why Low-BAC DWI Charges Can Be Challenged

One advantage in these cases is that the state’s evidence is often more subjective than in a per se DWI. Without a BAC of 0.08% or higher, the prosecution must rely heavily on the officer’s observations and field sobriety tests. An experienced defense attorney can challenge these types of evidence by:

• Pointing to medical or environmental reasons for your appearance or behavior
• Questioning whether the traffic stop was legally justified
• Reviewing whether field sobriety tests were conducted properly
• Examining whether the breath test equipment was maintained and used correctly
• Challenging the training and conclusions of a Drug Recognition Expert

By exposing weaknesses in the case, it may be possible to have the charges reduced or dismissed.

What You Should Do If You Are Charged Under 0.08%

If you are facing a DWI charge despite being under the legal BAC limit, take these steps immediately:

• Write down every detail you remember about the stop, including what the officer said and did.
• Save receipts, credit card statements, or other records showing what you ate or drank before driving.
• Avoid talking about your case with anyone other than your attorney.
• Contact a defense lawyer as soon as possible.

The earlier you involve an attorney, the better your chances of building a strong defense.

Call Denise Kirby Today to Protect Your Future

A DWI under the legal limit can be confusing, frustrating, and frightening. You may feel like the situation is unfair, but you do have options. We have helped many clients successfully fight low-BAC DWI charges in Missouri. We know how to identify problems in the state’s case and use them to your advantage. If you are facing this situation, contact us today. We will review your case, explain your options, and work to protect your rights, your license, and your future.