Like other Wisconsin residents, you were probably led to believe that roadside breath testing machines give law enforcement officers an accurate indication of whether you drank too much before driving. The police officer who stopped you and administered the test certainly isn't going to tell you that the results may not be right.
Like any other technological device, these machines require maintenance, including calibration, in order to function as intended. If officers fail to keep the machines they use calibrated, they could easily return bad results, which could wrongly land you in jail after a DUI stop.
How do you know if the machine worked properly?
Many people accused of DUI ask this question, and so do the courts. Before a court will allow the prosecution to admit the results of a roadside breath test into evidence, it considers the following basic factors followed by most states:
- Departments receive a list of acceptable devices to use, and the one they use must be on that list.
- The officer who administered your test must receive certification in order to use the device.
- The device used must receive proper maintenance, along with regular accuracy checks on a set schedule.
- The officer must administer the test as trained to do so.
- The officer must end up with two results within .02 of each other.
- The officer must make sure that the person taking the test has not vomited, eaten, burped, smoked or regurgitated immediately prior to the test.
If the state can't prove the officer and/or the department followed all of these guidelines, the court may throw out the results. One of the most common issues when it comes to breath testing machines is calibration. You may gain access to the records for the particular machine used by the officer during your DUI stop. If the records indicate that it did not receive the proper, routine maintenance or did not undergo proper calibration prior to your test, that piece of evidence may not stand up in court.
The prosecutor will then have to find another way to prove beyond a reasonable doubt that you were, in fact, legally drunk when the officer stopped you. This is when subjective evidence such as your appearance, your speech and more come into play. In your case, you may be able to challenge other evidence as well, so a thorough examination of all evidence and the circumstances under which your stop occurred is in order.