In the majority of DUI cases, an important piece of evidence is the blood alcohol level of the accused at the time of the incident. However, in certain circumstances it is possible to challenge breathalyzer results in court.

Whether or not this is possible for you depends on your particular case. According to FindLaw, the two major ways to challenge a breathalyzer are to either question the machine itself or the training of the officer who used it.

What could be wrong with the breathalyzer? 

Breathalyzers are machines, which means that they have the potential to malfunction. For example, in a DUI case in Iowa a man was able to blow a “HI” reading on a breathalyzer in the courtroom while entirely sober.

Even if the breathalyzer itself is functioning, somebody must calibrate it in order to work properly. Usually, an officer will provide testimony to this fact. However, if the officer cannot do this it is possible that the courts will throw out the case.

What could be wrong with the officer’s training?

Just like with radar guns, police must be properly trained to use breathalyzers. Usually the officer will provide testimony that the police trained the officer in the use of breathalyzers. However, again, if the officer cannot do this it is possible the courts will not admit the results of the breathalyzer.

The police also must have had probable cause to make you submit to testing. Again, an officer must testify that you were exhibiting signs of drunkenness or erratic driving. Otherwise, the police performed the test in an illegal manner and the courts will not admit the results.