Exploring the 7 Most Common Defenses for DUI/OWI Cases

For those caught in the complexities of a drunk driving charge, it’s important to understand the defenses available. The most common defenses often revolve around the specifics of the initial traffic stop, consent warnings, and the accuracy of blood alcohol concentration readings.

This article delves into these common strategies, shedding light on how they can be used and their potential impact on the case. By understanding these possible defense options, individuals caught in DUI/OWI cases can work with an experienced criminal defense lawyer on a robust defense strategy.

What is a DUI/OWI?

DUI (Driving Under the Influence) and OWI (Operating While Intoxicated) refer to driving with a blood alcohol content that is over the legal limit of .08%. This is more commonly known as drunk driving. A driver can also be charged if they are impaired by other substances such as drugs or medication.

Unlawful Traffic Stops

One of the more frequently utilized defenses in DUI/OWI cases is challenging the legality of the initial traffic stop. The Fourth Amendment of the U.S. Constitution protects individuals from unreasonable searches and seizures, including improper traffic stops.

For a traffic stop to be legally justified, law enforcement must have a valid reason, such as a traffic violation or suspicion of criminal activity based on observable facts. If it can be demonstrated that the stop was not warranted, any evidence obtained during the stop, including breathalyzer results or field sobriety test performance, could potentially be suppressed.

There’s a lot to unpack with unlawful traffic stops, so if this pertains to you we recommend referencing our past article about unlawful traffic stops in Milwaukee.

Lack of Probable Cause

Probable cause refers to reasonable grounds that a crime has been committed, which justifies an arrest. This is a higher standard than reasonable suspicion, which could lead to a stop but not necessarily an arrest. Essentially, for an arrest to be valid, law enforcement must have probable cause to believe that the individual was driving or operating a vehicle under the influence. If it can be established that the police lacked probable cause for the arrest, any evidence gathered subsequently could be deemed inadmissible.

Incorrectly Performed Tests

Field sobriety tests and chemical tests, like breath or blood tests, are frequently used by law enforcement to test for impairment. However, these tests can be subject to human error, equipment malfunction, or procedural inconsistencies.

Field sobriety tests, including the one-leg stand, walk-and-turn, and horizontal gaze nystagmus tests, heavily rely on the officer’s interpretation. Chemical tests also have their pitfalls. The breathalyzer device, for example, must be properly calibrated and maintained to yield precise results. If any aspect of the testing process is improperly executed, it could provide grounds for challenging the test results.

Calibration Issues

Calibration issues with breathalyzers form a crucial aspect of defense in DUI/OWI cases. Breathalyzers are intricate devices that need regular calibration to ensure their accuracy. The calibration is a process where the device is adjusted to measure the alcohol content correctly in a subject’s breath. If a breathalyzer is not properly calibrated, it can yield inaccurate results.

Improper Warning

Improper warnings can play a significant role in the defense strategy for DUI/OWI cases. For instance, during a DUI arrest, an officer is required to provide certain warnings to the suspect, known as Miranda warnings. These inform suspects of their right to remain silent and their right to an attorney. If these warnings are not given, any incriminating statements made by the suspect may be excluded from the evidence.

Moreover, officers must also provide implied consent warnings before administering chemical tests. Failure to do so could invalidate the results of these tests.

Prescription Drugs

Prescription drug use can be a viable defense in DUI/OWI cases. While it’s illegal to drive under the influence of drugs, including prescription medications, it isn’t unlawful to drive while taking prescribed medication as directed by a healthcare professional. If a person is charged with a DUI/OWI and their impairment was due to the use of prescription drugs taken as instructed, they may have a valid defense.

Interfering With Evidence

Evidence in DUI/OWI cases typically includes breathalyzer results, blood tests, field sobriety test results, or even video footage from a police dashcam. If it’s proven that the evidence was tampered with, mishandled, or improperly stored, it could impact its reliability and admissibility in court.

For example, if a breathalyzer device wasn’t properly calibrated or maintained, the results may not accurately reflect the suspect’s blood alcohol content. Similarly, if a blood sample wasn’t stored correctly, it could lead to degradation or contamination, thereby skewing the results. If a defense attorney can demonstrate that the evidence in the case was interfered with, they may be able to get it excluded, which could significantly weaken the prosecution’s case.

At Fenton Law Office, our Milwaukee criminal defense lawyers have extensive experience in DUI/OWI cases. Our knowledgeable team can help you navigate the legal system and explore your options for a defense strategy. Schedule your consultation today.