Challenging Breathalyzer Test Evidence

Arrested for a failed breathalyzer test in Fort Myers or Naples?

If you have been charged with driving under the influence on the grounds that you failed a breathalyzer test, you may be worried that there is no way to avoid a conviction. After all, it would appear that there is positive and irrefutable scientific evidence of your guilt, so how could you possibly hope to beat the charges? Fortunately, it is frequently possible to challenge breath test results, invalidating what may be the most important evidence in your case.

How does a breathalyzer machine work?

Breathalyzers are used to determine the blood alcohol concentration of a DUI suspect, because state law makes a conviction for drinking and driving possible when the defendant is either impaired by alcohol or has a BAC above .08 while driving. The machine does not, however, directly measure BAC, but rather estimates it based on how much alcohol is in the suspect's breath. After you have had a drink, the alcohol enters your bloodstream, and a certain amount of alcohol evaporates out of your blood as it passes through the tissues of your lungs. This is what a breathalyzer measures.

While a breath test may be a better measure of whether a driver is guilty of DUI than standards such as field sobriety tests or the subjective opinion of a police officer, they are still not perfectly accurate. The equipment has an inherent margin of error even when perfectly calibrated, but many police departments do not properly maintain their machines, which can increase this margin to a point where the test results simply should not be admitted as evidence in court. To further complicate matters, consider the fact that the test is normally administered in the police station approximately one hour after the traffic stop, rather than immediately after the driver was behind the wheel.

Problems with Breath Test Results

Another issue involved in using breath test results as evidence in a DUI case is the fact that the machine cannot tell the difference between alcohol which has evaporated from the lungs and mouth alcohol, a term for the residual alcohol which is often left in a person's mouth after drinking. Mouth alcohol from having a single glass of wine could potentially cause a reading of .08 or more, possibly leading to a wrongful conviction. Other physiological factors can throw off the test accuracy, such as stomach gases and acid reflux. Diabetes can cause a false reading, given that a diabetic's body produces a higher than normal amount of acetone, a substance which the breathalyzer machine will nearly always confuse with ethanol. Radio frequency interference from the police officer's radio can even interfere with the electronics inside the breathalyzer.

Given that there are so many potential problems with the operation of a breath test machine, it is in your best interests to hire a Fort Myers DUI attorney from Parks & Braxton, PA to help you attack the evidence. With careful preparation and effective courtroom argumentation, we may be able to invalidate the test results, making it possible to have the charges dismissed so that you can walk away from this situation without undergoing the harsh penalties of a DUI conviction.