Yes, it is possible to challenge breathalyzer results, particularly if you believe you were not operating a vehicle while over the legal limit when an officer pulled you over.
Usually, whether an OWI sticks depends heavily on the breathalyzer results. If you can convince a jury that the breathalyzer was faulty or the police used it outside of the bounds of the law, you may be able to avoid OWI conviction. According to FindLaw, in order for breathalyzer results to be valid, the breathalyzer must be calibrated, reliable, delivered by an officer with breathalyzer training and the breathalyzer must not have been part of an illegal search.
What are some potential issues with the breathalyzer itself?
Breathalyzers are machines, and, as such, they may not always produce reliable results. In the past, juries and judges have found that certain breathalyzers are not scientifically reliable or not producing accurate readings. Even if the device itself is reliable, the device must be properly calibrated to produce accurate readings. As such, the state must provide testimony that the breathalyzer was properly calibrated prior to your arrest.
What are some potential issues with the use of the breathalyzer?
In the exact same way that you can challenge a speeding ticket if an officer has not been properly trained in the use of a radar gun, you can challenge a breathalyzer test. If an officer has not been properly trained in the use of a breathalyzer, the jury may find the results unreliable. Plus, in order to validate the breathalyzer results, there must have been probable cause to pull you over. Testimony must exist to prove that you were driving erratically, or producing slurred speech when the police pulled you over.