What You Need to Know About Challenging Breath Test Results in Maryland

Nov 12, 2017

The officer has pulled you over, but you wonder whether or not he or she really had probable cause to continue with a claim that you were under the influence. Perhaps the breath test said you were breaking the law, but you hadn’t had enough or anything to drink and you want to challenge the breath test results. If you’re thinking about this, you’re not alone.


In all drunk driving cases in Maryland, the prosecution bears the burden of proof to illustrate that the defendant’s blood alcohol concentration or BAC at the time of the offense was either at or higher than the statutory limit. The use of a breath test is one of the most popular methods for establishing that drunk driving has indeed occurred. However, some defendants wonder whether or not they can challenge the results of these tests in court successfully and prevent a conviction and the resulting consequences


There are several different bases through which a breath test result can be challenged. The breath test result for drunk driving involves measuring the amount of alcohol in a sample of the defendant’s exhaled air. While the test seems relatively simple to perform, there are major weaknesses in that this is considered an indirect method and is highly variable. The atmospheric pressure, the aerophysical activity level, the chemical composition of your blood, the temperature and possible hyperventilation are some factors that can influence the very ability of such a test. This means that your breath test results may be highly questionable and if these are used to pursue criminal charges against you, your Maryland DUI lawyer may bring this up in the pursuit of your case.


Test results could also be challenged due to the circumstances of the testing at issue such as the experience and skill of the tester, and whether the equipment used was of the highest quality and had been calibrated recently. Breath testing machines, like all machines, are subject to error when the person being tested has recently been exposed to particular substances. Consulting with an experienced Maryland DUI lawyer can help you figure out whether you have grounds to challenge the results.

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