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Challenging Breathalyzer Tests in Wisconsin OWI Cases

 Posted on December 08, 2020 in DUI/OWI

Milwaukee County criminal defense attorney OWI

When you are stopped for driving under the influence of alcohol or drugs in Wisconsin, you will generally be given a breathalyzer test, and its results will then be used as evidence to determine whether you should be charged with operating a motor vehicle while intoxicated (OWI) or not. However, what many are not aware of is that very often, breathalyzer test results are inaccurate. If you believe this has happened in your case, an experienced DUI defense attorney can help you ensure that your rights are protected. 

Several Reasons for Error

There are several different possible reasons that a breathalyzer test could be inaccurate. Some include: 

  • Improper calibration: If a machine is not recalibrated every so often, its accuracy will begin to falter. Wisconsin law sets out benchmarks that must be performed before a breathalyzer’s results can be deemed accurate, and your arresting department might not have performed this maintenance.

  • Residual alcohol in the mouth: A police officer must wait for at least 20 minutes after the driver has eaten or had anything to drink before administering the test because testing any sooner creates too high a risk that alcohol will be leftover in the mouth. Similarly, if a person has gastrointestinal reflux (GERD, or acid reflux), residual alcohol may be brought up in stomach acid.

  • False positives: It has been noticed in studies that certain substances, such as acetone, can produce false positives if present in the mouth. People with hypoglycemia or diabetes may particularly suffer from this, given that both conditions are known to deposit high levels of acetone in a person’s breath.

In addition to all these reasons for an inaccurate reading, it is of course possible that the arresting officer simply made a mistake or used the wrong procedure. 

Be Careful Of Admitting Alcohol Use

Challenging the result of a breathalyzer test is not an easy thing to do, because Wisconsin courts will generally accept breathalyzer evidence as valid as long as a reasonable person would be able to trust it. However, it is very possible as long as there is supporting evidence or you are able to conclusively demonstrate the possibility of error. Attempting to simply assert any type of defense in order to stave off consequences is something that the court will not take well. 

Keep in mind that if you made any kind of admission to the arresting officer about alcohol usage, you may begin even further behind the proverbial eight ball. While you may not have been arrested at the time of your admission, law enforcement is permitted to use anything you say during a stop against you. You are not required to provide any information beyond your name, address, and date of birth, as well as your driving record. Saying anything else can make your case more difficult. 

Call Our Waukesha County Criminal Defense Attorneys

If you are arrested for operating while intoxicated, you have the right to be treated fairly and to have your rights protected at all times. A false positive breathalyzer test can cause serious upheaval in your life. A dedicated Delafield OWI defense lawyer from Bucher Law Group, LLC can work with you to ensure that you get your fair day in court. Contact our offices today at 262-303-4916 for a free consultation. 



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