When a breath test is administered, the goal is simply to measure a driver’s blood alcohol concentration (BAC). This determines if they are over the legal limit of 0.08%. If they are, it can be presumed that they are impaired. If they are not, the police may still argue that they are impaired, but they will have to provide other proof of this allegation before they can justifiably arrest the driver for drunk or otherwise impaired operation of a motor vehicle.
Many people assume that breath tests are inherently accurate. After all, they’re very commonly used and they often serve as strong evidence in court. But are there some reasons that a breath test could actually be inaccurate? How could someone fail a breath test and appear to be over the legal limit when they actually were not?
The test wasn’t calibrated
One potential issue is that breath tests need to be calibrated at certain times to make sure they’re still working properly. If the breath test has been neglected and ignored, how sure can authorities be that the readings are correct?
The officer made a mistake
Additionally, a breath test is only a tool. It is only as useful as the person administering it. If a police officer makes a mistake in how they perform a test, then the results that they get may not actually be accurate. Similarly, police officers need to be trained prior to using breath tests. Lack of training can call the accuracy of the test into question.
Something else triggered the test
In some cases, a positive breath test result will actually be triggered by something that may not be a violation of the law. An example of this could be if the person taking the test recently used mouthwash. They could still have a high alcohol concentration in their mouth, which is going to give them a higher reading on the test, even though mouthwash doesn’t actually lead to any impairment.
These are just a few examples of why breath tests are not as dependable as people assume. Those who are facing drunk driving charges need to know about all their legal defense options, including the possibility of calling a breath test into question. Speaking with a legal professional about defense strategy is usually the best first step forward.