Reeder & Brown, P.C.


Are Breathalyzers Ever Wrong? 

 Posted on April 04, 2023 in Criminal Law

Will County Criminal Defense LawyerBreath alcohol tests, or "breathalyzer tests," as they are sometimes called, measure the amount of alcohol on a person's breath. This information is used to calculate the person's blood alcohol concentration (BAC). Often, a police officer asks a person to take a breathalyzer test during a traffic stop because they suspect the person is driving under the influence. While breathalyzers are commonly used to measure BAC levels, they are not always accurate.

If you or a loved one were arrested for DUI, you might be able to get the charges dropped or secure an acquittal by challenging the validity of the breathalyzer test results.

Roadside Breath Tests Versus Evidentiary Breath Tests

One of the most common misconceptions regarding DUI traffic stops involves the breath test period most people are not aware that there are two different types of breath tests used by police officers in Illinois. The first is a roadside, preliminary breath test. This test is used to demonstrate probable cause for a DUI arrest. However, the results of this breath test are not admissible in court. After somebody is arrested for drunk driving, they are taken to the police station and given a second, more accurate breath test. This is an evidentiary breath test. The results of this breath test can be used in a DUI case.

Problems with Breath Tests Can Lead to Invalid Results

Breathalyzers are machines, and like all machines, they can malfunction. This could lead to inaccurate readings. One of the most common problems with a breath testing device occurs when the device is not properly calibrated. Illinois law requires police officers to follow certain rules regarding the calibration, operation, and maintenance of breathalyzers. If the device was not properly calibrated, maintained, and operated in accordance with state laws, the results might be considered invalid.

Another possible cause of inaccurate readings is mouth alcohol contamination. This occurs when a person belches, regurgitates, or vomits before taking the breath test. This puts alcohol back in their mouth, which can lead to a falsely high reading. Specific medical conditions or medications can also make breathalyzer results inaccurate. Diabetes and acid reflux are two of the most common medical conditions that can interfere with breath tests.

Contact our Joliet Criminal Defense Lawyers

Inaccurate breath tests can be challenged in court. If you or a loved one were arrested for drunk driving, contact our Joliet DUI defense lawyers for help. Call 815-885-5980 for a free consultation.



Share this post:
Back to Top