Call to Schedule a Free Consultation


Breathalyzers: What Every Illinois Resident Should Understand About Breath Tests During DUI Stops

 Posted on November 08, 2022 in DUI

Wheaton DUI defense lawyerMost people are familiar with the handheld alcohol breath tests used by police officers to check for drunk driving. However, many people do not fully understand how, when, and why these devices may be used. Whether you or a loved one are facing charges for driving under the influence (DUI), or you simply want to be well-informed of your rights, understanding breathalyzers is crucial.

Portable Breath Tests Are Not the Same as Evidentiary Breath Tests

Illinois police officers carry portable breath testing devices in their patrol vehicles. These are called “preliminary tests” because they occur before an individual is charged with DUI. The purpose of a preliminary breath alcohol test is to provide justification for a drunk driving arrest. A police officer may ask a driver to breathe into the machine if the driver is slurring his or her words or smells like alcohol. The preliminary test will show a result. If the result is 0.08 percent blood alcohol concentration or greater, the driver is arrested for drunk driving.

Once someone is arrested, they are taken to the police station and asked to breathe into a second breath testing device. This evidentiary test is larger and more accurate than the preliminary tests officers carry around with them. Only the results of the evidentiary breath test may be used as evidence during a DUI trial. The preliminary test results are not admissible.

Breath Tests Can Be Thrown Off by Many Different Factors

Anything from using mouthwash to suffering from diabetes can throw off a breathalyzer. These tests are not foolproof. An evidentiary breath test may also be unreliable if the device is not properly calibrated, was not cleaned properly, or is defective in some way. The timing of a breath test can also cast doubt on the accuracy of the results. Blood alcohol concentration rises significantly after someone drinks. A person may be under the legal limit while driving but over the legal limit by the time police administer the second breath test.

A DUI Defense Lawyer May Question the Validity of a Breath Test

Fortunately, we are innocent until proven guilty in the United States. For someone to be convicted of drunk driving, his or her guilt must be proven beyond a reasonable doubt. A criminal defense lawyer may be able to help a defendant avoid conviction by demonstrating that the breath alcohol test was faulty or unreliable.  

Contact a Wheaton DUI Defense Lawyer

If you were charged with driving under the influence, you need a lawyer who will advocate on your behalf and protect your rights. Call DuPage County DUI defense lawyer Stephen A. Brundage at 630-260-9647 for a free consultation.



Share this post:
Back to Top