Due to the COVID-19 pandemic, we are conducting most of our consultations virtually, either on-line or over the phone. That said, if any of our clients or potential clients wish to visit our office in person, we are happy to see them, provided social distancing protocols are observed.

Frank, Juengel & Radefeld, Attorneys at Law

Local: 314-282-8657
Toll Free: 800-748-2105

Defenders Of The Accused
Matthew Radefeld & Dan Juengel

Felonious DWI convictions can lead to steep financial penalties, permanent revocation of a driver’s license, and even substantial prison time. When someone is pulled over under the suspicion of driving while impaired, there are a number of tests that a law enforcement officer may use to try and measure someone’s blood alcohol concentration, also known as BAC.

One of these tests is called the Breathalyzer, a machine that measures the amount of alcohol in someone’s breath and uses this as a surrogate for the estimation of BAC. If someone’s BAC is greater than 0.08 according to the Breathalyzer, a DWI conviction can result; however, there are numerous reasons that a Breathalyzer can return an inaccurate reading.

Is the Breathalyzer Properly Calibrated?

As stated above, the Breathalyzer will use the measured alcohol in the breath as a surrogate for the measurement of the BAC in the blood. In order for this reading to be accurate, it is important for people to understand that the Breathalyzer must be properly calibrated.

It is comparing the alcohol in the breath against a known measurement which the machine assumes is zero. By comparing this known zero to the alcohol on the breath, an estimation of BAC is generated. If the machine hasn’t been calibrated in a long time, the measurement can be thrown off. This can return an erroneous reading that could place an innocent person in jail.

Medical Conditions can Lead to Erroneous Breath Results

Another reason that the breath test could be thrown off is that there are other substances in the breath that could be misinterpreted by the machine. For example, some people have GERD (gastroesophageal reflux) or follow strict diets that could lead to an increase in the number of ketones in the stomach and in the breath. Because ketones are structurally similar to alcohol, there is always a chance that the Breathalyzer could misinterpret these substances as alcohol. This could lead to a faulty reading that could be used as evidence in court.

The Timing of the Breath Test is Important

When someone is pulled over, the breath test isn’t always administered immediately. For whatever reason, there could be a delay in administering the breath test. If this delay is substantial, the reading that shows up on the breath test may not accurately reflect the person’s condition when they were initially pulled over. The timing of the breath test matters.

It is important for people to understand that the breath test could be used as evidence that could lead to a conviction of a felonious DWI. This leads to strict penalties that can alter someone’s life. For this reason, it is important that individuals accused of drunk driving consult an experienced attorney who understands the reasons why a Breathalyzer reading may not be accurate and how to bring this information to light in court.