A breath test can become an important piece of evidence in a drunk driving case. Many people assume the number displayed on the device tells the whole story, but the circumstances surrounding the test can matter just as much.
Breath-testing devices are designed to help provide consistent results, but they still require proper equipment, procedures and handling. When something goes wrong, the accuracy or reliability of the result may become a question.
Factors that can affect breath test results
A breath test is done using Breathalyzer or similar device. It measures the amount of alcohol in a person’s exhaled breath. The device analyzes the alcohol-containing vapors and uses a chemical reaction to produce a reading that estimates the person’s blood alcohol concentration (BAC).
Breath-testing equipment needs to be properly maintained and calibrated to produce reliable results. If a device has not been maintained according to applicable requirements, has a mechanical problem or has not been properly calibrated, questions may arise about whether the reading was able to accurately reflect a person’s alcohol concentration. Records showing when the device was inspected, serviced or calibrated can be important when evaluating the test.
The way a breath test is administered can also affect the results. Officers generally need to follow established procedures when preparing someone for a breath test and operating the device. Issues such as improper operation, failure to follow required observation periods or problems with the testing process may provide reasons to examine the result more closely.
Other circumstances can also affect breath tests. Mouth alcohol, certain medical conditions and environmental factors may sometimes interfere with testing. The specific device, testing method and circumstances of the case all matter when determining how much weight should be given to a breath-test result.
The initial breath test number does not always equal guilt in a drunk driving case. Reviewing the testing records, equipment history and circumstances surrounding the test can help identify potential issues. If you are facing an OWI or other drunk driving-related charge, speaking with an experienced legal professional can help you understand the evidence and determine the best way to move forward.
