Challenging the Breath Test

Challenging the Breath Test in a DUI Case

Chicago DUI Lawyer

Many DUI charges are filed based upon a failed breath test. Although there are three different methods law enforcement will use to test for the presence and amount of alcohol and drugs in a driver's system, a breath test is typically the most frequently used method.

There are two primary reasons a driver will need to consult with an attorney after taking a breath test. A defense attorney can assist a driver who has "failed" or "refused" a breath test. Failing a breath test would mean that the driver showed a result of .08% or greater, or .02% or greater if the driver is under the age of 21. A driver may also face license suspension and possibly other penalties if he or she refuses to take a breath test after an arrest for suspected DUI. Under Implied Consent laws, drivers are considered to have given consent to alcohol testing after a drunk driving arrest (to obtain your driver's license in Illinois you sign a paper that includes a clause to this extent).

Arguments to Contest the Breath Test

Although you may have been accused of failing a breath test, there are ways that an experienced criminal defense lawyer may still be able to help you avoid a conviction. This may include bringing about such defenses as:

  • The breath test operator was not licensed. In Illinois, a breath test operator must have a valid license for test results to be admissible.
  • The Breathalyzer machine malfunctioned. If a breath test device is improperly calibrated or maintained, it may malfunction.
  • The breath test device used was not listed on the Federal List of Approved Breath Evidential Instruments.
  • The breath test was not administered properly.
  • The test was carried out with a portable breath test device, the results of which are inadmissible as evidence in court.
  • Breath test results are invalid due to an interfering substance – another substance that contains alcohol (cough syrup, asthma medicine, etc.) that may have led to a false positive.

Free Consultation

Email Us About Your Case


Make a Payment

Please click the below button to begin your online payments

Get the Help You Need—Now!

Work with an effective and experienced law firm in Chicago to resolve your legal matters.

Free Case Evaluation
Excellent representation!
- M. V.
Read more comments