Calibration issues can affect breath test results

On Behalf of | Jan 14, 2021 | Firm News

Wisconsin has implied consent laws, so if a police officer suspects you of OWI and pulls you over, you may find yourself facing a breath test.

Although courts often rely on the outcome of these tests, accuracy issues might cast doubt on breath test results, which, in turn, may help your case.

Wisconsin law

A breath testing device measures the blood alcohol concentration level in your system, and if your result is 0.08% or higher, you may face an OWI charge.

As a first offender convicted of OWI, you are looking at least at a fine, and possibly even license revocation for up to nine months. A second offense onward may result in fines, jail time, license revocation and the installment of an ignition interlock device.

Common issues with accuracy

A breath test device converts data produced by your exhaled vapor into a BAC measurement in order to arrive at your level of intoxication. However, breath test devices are not perfect as illustrated in 1988 when a court in New Jersey called out problems with the device. For example, design flaws caused readings that were too high, the temperature of the device was capable of causing a variance in the testing results and the calibration of a machine could be inaccurate for various reasons.

The Philadelphia example

In the summer of 2016, a private attorney notified the Philadelphia Police Department that the calibrations on all their breath test devices had expired. The solution that establishes the accuracy of BAC readings required replacement, and the machines needed proper recalibration.

This seemingly simple problem had an unforeseen effect on the results for hundreds of DUI cases in the previous six months. Attorneys could go back to court on behalf of their clients and argue that the results of the breath tests with the expired solution could be inadmissible in a court of law.

Issues with test refusal

Some drivers stopped on suspicion of OWI refuse to take the breath test, which can result in further legal problems. While there may be a way to challenge the results, the refusal results in an automatic license suspension, and you can receive an OWI conviction without the breath test results.