When a police officer asked you to perform a breath test during a traffic stop, you didn’t hesitate. You either knew you had nothing to drink or consumed far less than it would take to intoxicate you.
Somehow, however, the breath test showed that you were over the legal limit, and the police officer arrested you. You may have started to second-guess yourself if you thought that you had been responsible about your drinking. After all, you probably put a lot of faith into forensic and chemical evidence.
Despite how reliable chemical testing can be, there’s a noteworthy chance that the test results were inaccurate. What are two possible reasons why a chemical breath test would show an inaccurately high blood alcohol concentration?
The test misidentifies other substances
Collecting and analyzing the exhaled breath of a person for certain kinds of molecules is a quick and efficient way to check for alcohol-impaired drivers, but many innocent people can also fail those tests.
The way that chemical breath tests work does create a significant risk of false-positive results. Acetone in the exhaled breath of someone with uncontrolled diabetes or residual asthma medication could both cause false-positive results when someone provides the chemical breath sample.
The device needs calibration, maintenance or software updates
Breath tests are delicate scientific equipment. To return an accurate result, the test needs frequent calibration. Sometimes, the manufacturer may release software updates or patches that are necessary for reliable performance. Frequent maintenance is the only way to ensure that test results are accurate.
Exploring what may have caused a failed breath test could give you options for different defense strategies against drunk driving charges.