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Challenging Breathalyzer Results: Protecting Your Rights in a DWI Case

by | Oct 3, 2023 | Criminal Defense |

This morning I was reviewing over a new DWI case.  While reviewing over the police report, I noticed the police officer didn’t mention whether or not the breathalyzer machine had been properly calibrated or maintained.  This is a problem.  Now…there isn’t anything to say that the police officer will get up on the stand when questioned by the prosecutor and say that it was in fact properly maintained and calibrated… but it’s my job to make sure that is asked.   In a world where 90% of my clients have submitted to a breathalyzer test, it’s important to understand these machines.  What’s even more important is knowing how to fight them and make sure you aren’t getting the raw end of an otherwise faulty breathalyzer machine.  When it comes to DWI (Driving Under the Influence) cases, the most crucial piece of evidence used by Louisiana law enforcement is the breathalyzer test. But just how reliable are these devices from the perspective of a criminal defense attorney? Let’s take a closer look.

1. Calibration and Maintenance:

Breathalyzer machines must be calibrated and maintained regularly to ensure accurate results. Failure to do so can lead to skewed readings. As a defense attorney, I often scrutinize the maintenance records of these devices to check for any irregularities. If the breathalyzer was not properly calibrated, it could raise doubts about the accuracy of the test results.

2. Margin of Error:

No breathalyzer is completely error-free. These machines have a margin of error that can vary from device to device. This means that the reading you receive may not be an exact representation of your blood alcohol concentration (BAC). As a defense attorney, I question the reliability of breathalyzer results when the margin of error is significant, especially if it could tip the scales in a DUI case.

3. Environmental Factors:

Breathalyzer accuracy can be affected by various environmental factors, such as temperature and humidity. Additionally, certain medical conditions or medications may impact the results. As a defense attorney, I investigate whether these factors played a role in my client’s case, as it could provide grounds for challenging the breathalyzer’s reliability.

4. Operator Error:

The person administering the breathalyzer test must follow specific protocols to obtain accurate results. Any deviation from these procedures can compromise the reliability of the test. As a defense attorney, I investigate whether the arresting officer followed proper protocol when administering the test, as any errors or shortcuts can be used to challenge the results in court.

5. Rising Blood Alcohol Levels:

Alcohol absorption rates in the body can lead to rising blood alcohol levels, meaning your BAC may continue to increase even after you’ve stopped drinking. If the breathalyzer test is administered during this absorption phase, it can result in a higher reading than your actual BAC at the time of driving. This is a critical factor that I, as a defense attorney, consider when assessing the reliability of breathalyzer results.

Bottom line, while breathalyzer tests are a common tool used in DWI cases, their reliability is not absolute. It’s my duty to examine every aspect of a DWI case, including the accuracy and reliability of breathalyzer results. If there are doubts about the validity of these results, it can significantly impact the outcome of a case and may lead to reduced charges or even a dismissal. If you’ve been charged with a DWI, it’s essential to consult with an experienced attorney who can assess the evidence, including breathalyzer results, and determine the best strategy for your defense.  Call me today at 504-434-7000 for a confidential consultation.  We’ll discuss your case and make sure you don’t get the wrong end of a breathalyzer test.