A DWI charge can have serious consequences in Missouri, including jail time, fines, and a suspended license. However, being charged does not mean you’ll be convicted. Prosecutors must prove beyond a reasonable doubt that you were operating a motor vehicle while intoxicated, and much of that case relies on the evidence collected during the traffic stop and arrest.
Experienced defense attorneys focus on challenging this evidence. Here are the most common ways attorneys can advocate for their clients.
Challenging the Traffic Stop
The Fourth Amendment of the U.S. Constitution protects us against unlawful searches and seizures. This includes improper traffic stops. A police officer must have a legitimate legal reason to stop your vehicle before they can arrest you for DWI.
If the officer lacked reasonable suspicion to initiate the stop (such as if they pulled you over without observing any actual traffic violation), that arrest might be unlawful. Your attorney may file a motion to suppress any evidence obtained after an unlawful stop, which could include field sobriety tests, breath or blood test results, and any statements you made. If the court agrees the stop was unlawful, the evidence may be excluded, often resulting in dismissal of the case.
Attacking Field Sobriety Test Reliability
Standardized field sobriety tests (SFSTs) are often used to determine whether a driver is impaired. These include the one-leg stand test, the walk-and-turn test, and more. However, these tests are notoriously subjective and often improperly administered.
The National Highway Traffic Safety Administration (NHTSA) has strict guidelines for how SFSTs must be conducted. If an officer deviates from their training, your attorney can challenge the results.
For example:
- Uneven pavement can impact balance-based tests
- Certain medical conditions, medications, or age can mimic signs of impairment
- Officers may misinterpret nervousness or fatigue as signs of intoxication
Attorneys may review bodycam footage, police reports, and cross-examine the arresting officer to uncover inconsistencies. If successful, the court may rule the tests inadmissible—or give them little weight.
Questioning Chemical Test Result Accuracy
Breath, blood, and urine tests are common evidence for DWI cases, but they are not foolproof. Skilled attorneys can challenge their accuracy, calibration, and administration. For example, breathalyzers must be properly maintained and calibrated. If records show improper maintenance or expired certifications, the results can be thrown out.
Attorneys may also challenge whether the officer observed the appropriate waiting period before administering the test or whether acid reflux or other medical conditions could have skewed the result.
Similarly, blood and urine tests must follow a strict chain of custody. Contamination, improper storage, and processing delays can compromise the results.
If chemical tests are suppressed or questioned, a skilled DWI defense attorney can significantly weaken the case.
Learn About Your Legal Options from a Missouri DWI Defense Attorney
Whether a traffic stop, field sobriety testing, or chemical test, every part of the prosecution’s case must meet legal standards. If any part falls short, it can result in reduced charges, a plea deal, or case dismissal.
If you’ve been charged with DWI in Missouri, contact the skilled DWI attorneys at Travis Noble, P.C. today.