Defending a Charge of Driving Under the Influence: Challenging a Breath Test

If you have been arrested for driving under the influence and a breath test was used to determine your blood alcohol content (BAC), it is important to be aware of possible defenses to the use of such a test to prove you guilty of a DUI. Possible defenses include, but are not limited to, the following:

1) Inadequate or broken observation period. In order to properly read your BAC by a breath test, the testing officer must observe you continuously for at least 15 minutes before taking a sample. If you belch, vomit, or regurgitate gas in your mouth before the test, your BAC may read inaccurately high. If the officer has not observed you continuously for 15 minutes prior to measuring your BAC, it will be impossible for him to say that you did contaminate your own breath test.

2) Something in your mouth causes an inaccurate reading. Common items such as cough drops, breath mints, or chewing tobacco may remain in your mouth when a breath test is administered and can contaminate the results.

3) Your own personal medical history. If diagnosed prior to your arrest for DUI, many conditions, such as gastric reflux disease, intestinal problems, diabetes, and respiratory problems, can be used to show the likelihood of an inaccurate BAC reading from a breath test.

4) Your own personal dental history. Gum disease, gingivitis, and pockets around the roots of your teeth, as well as dentures or bridgework may trap alcohol in your mouth and contaminate a breath sample.

5) Your behavior or actions do not match test results. If there are witnesses, video tape, or observations by officers that suggests you were not intoxicated, it may be possible to challenge the readings from a breath test.

6) Rising blood alcohol level. If your first breath sample registers slightly over the legal limit, and a second sample taken later is higher, it is clear your BAC is rising. If this is the case it may be possible to argue that, at the time you were driving, your BAC was not over the legal limit.

7) Inexperience or incompetence of the arresting or testing officer. If the officer who arrested you or took your breath sample is not trained in the proper procedure or fails to follow protocol it may be possible to have the results of the improperly administered breath test thrown out.

8) Accuracy of the breath test machine. An artificially high reading can result from interference with the circuitry of a machine due to radio interference, shared power sources, or smoking in or near the machine.

9) Irregular samples. Consecutive BAC readings that vary a great deal can be used to challenge the accuracy of breath samples.

10) Statutory time limit. The prosecution must prove that the breath sample was obtained within three hours of the time you were driving in order to invoke the presumption that you were intoxicated at the time you were driving.

These are just a few of the many defenses that may be available to you if you have been charged with a DUI on the basis of a breath test. Of course, countless more defenses are available depending on the circumstances of your case. Contact the Law Offices of Scott R. Ball today to discuss your case and determine what defenses may be available for you. As always, a consultation regarding your case is completely free and totally confidential.