Challenging Breathalyzer and Blood Test Results in DUI/OWI Defense

Challenging Breathalyzer and Blood Test Results in DUI/OWI DefenseWhen facing a DUI and the evidence against you involves breathalyzer and blood test results, it can be a challenging road to navigate. These tests, often perceived as irrefutable, play a significant role in DUI/OWI convictions. However, what many don’t realize is that these tests can be challenged and are not always an accurate representation of one’s level of impairment.

This article will explore the intricacies of these tests, common issues associated with them, and how your legal team can employ strategic defenses to challenge their validity.  This article will cover:

  1. DUI/OWI Laws in Milwaukee
  2. Understanding Breathalyzer and Blood Tests
  3. Common Issues with Breathalyzer and Blood Tests
  4. Legal Rights When Facing a Breathalyzer or Blood Test
  5. The Role of a Dedicated DUI Attorney in Your Defense
  6. Fenton Law: Your First Step Towards a Strong DUI/OWI Defense

1. DUI/OWI Laws in Milwaukee

Understanding DUI/OWI laws in Milwaukee is the first step in building a strong defense. Under Wisconsin law, having a blood alcohol content (BAC) over the legal limit of 0.08% is enough to be charged with violating the state’s OWI laws. For drivers with three or more prior OWI convictions, they cannot operate a motor vehicle if their BAC is greater than 0.02%.

Penalties for a first OWI/DUI in Wisconsin typically include no jail time unless the driver had a minor passenger, and fines ranging from $150 to $300. However, a fourth drunk driving offense could potentially result in a lifetime driver’s license revocation. This is why it’s crucial to have an experienced DUI attorney on your side to protect your rights and navigate the complexities of these laws.

2. Understanding Breathalyzer and Blood Tests

Breathalyzer tests are commonly used by law enforcement to measure a person’s blood alcohol concentration (BAC) during a DWI arrest. They are favored for their convenience and immediate results, but they may sometimes provide inaccurate readings

On the other hand, blood tests, which involve taking a sample of the individual’s blood to measure the amount of alcohol present, are considered more reliable and less likely to be contested in court. However, the accuracy of both tests can be influenced by a variety of factors, including the device’s calibration, the procedure’s administration, and the individual’s physiology.

3. Common Issues with Breathalyzer and Blood Tests

While breathalyzer and blood tests are often central to DUI/OWI prosecutions, they are not infallible. Several factors can influence their accuracy and reliability, leading to potential false positives. For instance, breathalyzers require regular calibration to ensure correct readings; failure to do so could yield inaccurate results.

Similarly, operator error, such as incorrect administration of the test, can also lead to skewed results. Medical conditions like diabetes, acid reflux, or even certain diets can affect the breathalyzer’s reading due to the presence of acetone in the breath.

Blood tests, although generally more accurate, may also be compromised due to improper storage, contamination, or errors in the lab analysis process. Furthermore, these tests only provide a snapshot of a person’s blood alcohol content at the time of testing, not necessarily at the time of driving. You can review our previous article “Exploring the 7 Most Common Defenses for DUI/OWI Cases” for more on possible defense strategies.

4. Legal Rights When Facing a Breathalyzer or Blood Test

When faced with a breathalyzer or blood test during a DUI/OWI stop, it’s essential to know your legal rights. While laws vary from state to state, the principle of implied consent often applies. This means that by virtue of holding a driver’s license, you have essentially said yes to  taking these tests if lawfully requested by an officer. Refusing to take a test can result in immediate penalties, including license suspension for up to a year, fines, and in some cases, jail time.

Generally, you cannot choose a blood test over a breathalyzer, and refusing a breathalyzer but then agreeing to a blood test may still result in an automatic license suspension. However, in some circumstances, officers may need a warrant to perform a blood test, especially if you are unconscious.

Refer to our article “The Do’s and Don’ts After Being Arrested for a DUI/OWI” for more on what steps to take after an arrest. Remember, it’s crucial to consult with a qualified OWI attorney to understand your rights and the best course of action in your specific situation.

5. The Role of a Dedicated DUI Attorney in Your Defense

A dedicated DUI lawyer plays a pivotal role in challenging breathalyzer and blood test results in your DUI/OWI defense. With their intricate understanding of DUI laws, they can scrutinize the circumstances of your arrest, the administration of the tests, and the handling of the results for any procedural errors or inconsistencies.

Breathalyzer and Blood Test Flaws For Your DUI/OWI CaseThey can also challenge the reliability of the devices used, the qualifications of the officer or lab technician, and even the validity of the initial traffic stop. Additionally, they can navigate the complexities of implied consent laws and help you understand the potential consequences of refusing these tests.

Their expertise allows them to present compelling arguments in court, potentially leading to reduced charges or even dismissal of the case. In short, a dedicated local OWI lawyer is essential in ensuring that your rights are protected and that every possible defense strategy is explored.

6. Fenton Law: Your First Step Towards a Strong DUI/OWI Defense

Choosing Fenton Law as your legal representation is the first step towards building a strong DUI/OWI defense. With a deep understanding of drunk driving laws, our criminal defense attorneys at Fenton Law can navigate the complexities of your case, scrutinizing every detail from the initial traffic stop to the administration of breathalyzer and blood tests.

We offer comprehensive criminal defense services, including appeals for DUI and OWI cases. By choosing Fenton Law, you’re not just hiring an OWI attorney; you’re securing a dedicated advocate who will tirelessly work to protect your rights and explore every possible defense strategy. If you’re looking for an OWI attorney in Milwaukee, contact Fenton Law today for a free consultation.


By Attorney Jay Fenton, Owner of Fenton Law Office

Jay Fenton is a top-rated criminal defense attorney in Milwaukee who goes above and beyond for his clients. He has successfully secured favorable outcomes in countless cases, from negotiating plea agreements to filing pre-trial motions and managing complex appeals. Attorney Fenton also has had tremendous success achieving not-guilty verdicts at trial. His dedication and aggressiveness make him one of the best attorneys around.