Phoenix DUI Lawyer Blog

Arizona DUI police and prosecutors use breath, blood and urine to prove its case to the jury and seek an AZ drunk driving conviction. The breath test is usually given at the police station or in the AZ DUI van. This breath test is not without its faults and is highly susceptible to error. If the breath test is not given properly, then it will not accurately measure your blood alcohol concentration. A good Arizona DUI Lawyer may be able to file the appropriate motion to ask the judge to throw it out.

Below are some factors that can impact the accuracy and reliability of breath test results:

Temperature of Your Breath
The breath test works on the assumption that your breath is 34 degrees centigrade. Studies done with this equipment have shown that the real average breath temperature for people who have been arrested on a DUI/DWI is closer to 35.5, with some as high as 37. Thus, any error in quantification of the person breath temperature could provide incorrect blood alcohol content (BAC) results.

How Fast the Body Eliminates Alcohol
Another assumption on the part of the breath testing machine. Not all persons metabolism is the same, but the breath test machine assumes that everyone is the same. A person whose body gets rid of alcohol slower will have a higher BAC than someone with a faster metabolism. If you have a slow metabolism, you might still be absorbing alcohol by the time you take the test. If so, the machine will read your BAC higher than it actually is.

Belching, Hiccupping or Vomiting Prior to a Test
Part of the breath test mandates the officer to constantly observe you to verify that you have not belched, hiccupped or vomited within 15 minutes of taking the test. Constant observation is a rule that the officer must follow. If it is not followed, the results of the test may be called into question.

Inherent Margin of Error The breath machines have an acknowledged + 10% margin of error. Therefore, even when the device is calibrated and operating properly, it will still have a 20% range of error.

Mouth Alcohol The breath testing machines are frequently having difficulties distinguishing between alcohol in a person's mouth and blood alcohol. Contaminants in a person's mouth, such as, smokeless tobacco, denture adhesives, mints, and lip balm may also result in erroneous BAC results.

Operator Error Arizona DUI police often lack proper training in the use of the DUI breath test machines. Officers generally receive minimal training in the use of the device for purposes of AZ DUI Testing, and are not provided adequate written materials.

Despite efforts by the breath test machine manufacturers to detect these problems, they continue to result in many unjust Arizona DUI convictions, despite the fact they were innocent of Arizona Drunk Driving. Thus, another reason, to retain AZ legal representation from an experienced Arizona DUI Attorney who can provide you with the best AZ DUI defense possible.