During a DUI stop, the most common test which the police officer will ask the driver is to submit to a breath test. In some cases the police may take the driver to a nearest test center or a hospital, to submit a saliva, blood or urine sample, to get an accurate measure of the Blood Alcohol Concentration (BAC). However, if the breath test is not taken correctly, it can end up measuring the level of alcohol incorrectly, leading to a DUI charge. Due to this reason, alcohol breath tests are considered unreliable in most states, and your DUI defense lawyer can challenge a breath test report in court for inaccuracy.
Why are breath tests inaccurate?
There could be several reasons for a breath test to be unreliable, which are discussed below. Basically, a breath test measures the level of alcohol present in the lungs, and exhaled through breath. When a driver is asked to breathe into the breathalyzer or an Intoxilyzer, any residual air in the mouth can give a mistakenly high level of BAC. Other environmental factors can also affect the accuracy of a breath test, such as temperature, body weight and eliminating capability of the body etc.
Temperature of the breath
An accurate breath test works when the breath is at 34 degrees centigrade. However, studies show that breath temperature varies from 35.5 centigrade to as high as 37 centigrade from person to person, which can result in low or too high results on the breathalyzer. Normally, the results can vary from 10% to 20% from the actual reading due to a change in temperature.
Metabolism rate of the person
Every persons body has a different metabolism rate, which can end up giving high or lower levels of alcohol. Two people with varying metabolic rates will have different levels of BAC if a person has a slower metabolism, and the other one has a faster metabolism. Usually, people with slower metabolisms show higher levels of BAC than those with a faster metabolism, even if they took equal number of drinks. Similarly, the absorption rate of alcohol differs from person to person, and also if the drink was taken on an empty stomach or with some food.
Most breath tests assume that the person is “post absorptive” i.e. alcohol is no longer being absorbed into the blood stream from the person’s digestive tract. People with slower metabolism, or those who have had food along with the drink might still be absorbing alcohol into the blood stream at the time they are stopped as a suspect for DUI. People with slower metabolisms will get rid of alcohol slowly from their blood stream, and hence can end up with a very high BAC level.
Taking a breath test after belching, hiccupping or vomiting
In the case if the driver was hiccupping, belching or even vomiting prior to taking a breath test, chances are that he/she will have a higher level of alcohol on the breath. Therefore, it is the duty of the police officer to ensure and observe that the driver has not belched, hiccupped or vomited during the past 15 minutes before a breath test is carried out. If care is not taken in this regard, your DUI lawyer can defend you in court using this as the basis of defense.
Use of dentures and problems in the mouth
If the driver being tested for breath alcohol levels uses dentures or has any other problems associated with the mouth, it can trap alcohol in the mouth, causing the BAC results to be inaccurate and high. Again, this can be challenged in court and used as a defense strategy by your DUI attorney, to help you win the case.
Similarly, if a person has chemical compounds which are naturally present in the mouth, it can affect the BAC reading. The breathalyzer not only registers the level of alcohol molecules called ethyl alcohol, but it also measures other natural compounds present in the breath which can inflate the BAC reading.
How your DUI lawyer can defend you
If you have been charged with a DUI, your best DUI lawyer will be trained and knowledgeable about how to deal with the inaccuracies of breath tests. If the prosecutor uses the results of the breathalyzer as proof against you, it can be proved as unreliable and inaccurate.