How Can DWI Tests Be Inaccurate?

Texas DWI attorney Stephen Hamilton discusses how the police can misinterpret DWI tests to think you have committed a DWI offense.

Horizontal gaze nystagmus is typically the first of the DWI tests an officer will perform, and it is meant to test for an involuntary jerking of the eye. The officer moves a pen back and forth in front of your face to see if your eye moves at certain angles when the pen is held at certain distances. If your eye twitches horizontally, the officer will claim it’s a sign that you’re intoxicated. There are several problems with this.

The Walk-and-Turn and One-Leg Stand are balancing and dexterity DWI tests. Essentially, this is about a police officer who has known you only minutes while under very stressful circumstances, with no knowledge of your medical history, making a judgment call about your normal physical faculties of balance and dexterity. There are several fairly obvious problems with these tests.

How did the officer conduct the test? How long did they make you walk away before instructing you to turn and come back? Sometimes they tell you to not start the test too soon, or they will tell you to stay in a certain position until they say to start. If you start too soon because you’re nervous or uncomfortable in that position, they’ll count that against you.

A DWI charge does not guarantee a conviction, not if you have a defense attorney trained in field sobriety and Breathalyzer tests, with extensive knowledge of the science behind these tests, and access to experts who know even more about them can make a huge difference.

Talk to your lawyer immediately so he can take photos of the location of your tests and look into any medical conditions you have that could affect your performance. The sooner you get started building your defense, the better.