If you are facing charges for driving while intoxicated, chances are one piece of evidence includes the results of a roadside test. But, despite what the advocates of these tests may claim, they are not always accurate. In fact, you may be able to convince the judge to reduce your charges or dismiss your case altogether by showing the test results are unreliable.

There are several tests for a DWI, the two most notable ones being a field sobriety test and a Breathalyzer test. Here are some reasons why both of these tests may not hold up in court.

Field sobriety tests

First, it is important to understand the components of a field sobriety test:

  • Walk-and-turn: The police officer asks you to walk heel-to-toe in a straight line for nine steps. Then, the officer instructs you to turn on one foot and walk back in the same manner.
  • Horizontal gaze nystagmus: The police officer observes your eyes as you follow a moving object, such as a flashlight or pen.
  • One-leg stand: The police officer has you stand on one leg and balance.

These tests are often simply inaccurate. Studies show that field sobriety tests only provide 81% to 91% accurate results.

Other times, the police officer may not execute the tests correctly. If the officer does not perform these tests according to the strict guidelines from the National Highway Traffic Safety Administration, you may be able to challenge the tests in court.

Mental and physical conditions may also impact the accuracy of these tests. Common conditions that may skew the results include ear infections, neurological injury and skeletal disorders.

Breathalyzer tests

There can be a margin of error of up to 50% in Breathalyzer results. Factors that may cause issues with Breathalyzers include improper calibration, software glitches, human error and the presence of other alcoholic substances such as mouthwashes.