Updated on December 6th, 2022 at 07:58 pm

How your lawyer will evaluate a field sobriety test

When you hire a Milwaukee DUI defense lawyer, one of the first things he or she is going to do is evaluate the results of your field sobriety tests—not just your performance on the tests, but how they were administered. There are strict protocols for how field sobriety tests are supposed to be given, but police do not always observe these protocols. A test that was not properly administered does little to prove that you were intoxicated. Your Milwaukee DUI defense lawyer will look for testing errors such as the following:

Balance test – Coordination tests

The walk-and-turn test and the one-leg stand test are both supposed to be performed in a dry, level, well-lit location. If you performed the test by the side of the road, it can be helpful to revisit the scene to see if anything about the location rendered it less than optimal. Your physical condition can also make it difficult for you to perform these tests. A back or leg injury or an ear infection can limit your ability to stand or balance. If you are overweight, that may also negatively affect your performance.

Milwaukee DUI defense lawyers will sometimes ask their clients to recreate balance and coordination tests in court. If you are unable to perform the test in such a setting, it can be effective in countering the prosecution’s contention that your poor performance at the time of your arrest was due to intoxication.

Horizontal gaze nystagmus test

The most frequent problem that arises with the horizontal gaze nystagmus test (which measures the involuntary jerking of your eye) is that HGN is a phenomenon that occurs whether or not a person is intoxicated, and different people naturally display HGN to different degrees. The arresting officer will not have observed your normal performance on the test, so he will have no baseline with which to compare his observations at the time of your arrest.

Another problem with this test is that while intoxication affects horizontal gaze nystagmus, it is not the only factor that does so. Coming home tired after a long day at work could cause you to “fail” the test, as could allergies or eye irritants. Your Wisconsin defense lawyer will look for these and other weaknesses to present in court.