Being pulled over on suspicion of drunk driving can be a humiliating experience, especially when you are asked to get out of your vehicle and perform some field sobriety tests at the side of the road. Iowa law enforcement officers use three standard tests: the walk-and-turn, the one-leg stand and the horizontal gaze nystagmus (HGN) test.
The first two tests are basically tests of coordination and balance. In the walk-and-turn test, the driver is told to walk a certain number of steps heel-to-toe in a straight line, then turn around and walk back the same way. If the driver fails to keep a straight line or uses their arms to maintain balance, the officer can use that as evidence of impairment.
The one-leg stand test involves raising one foot off the ground while counting to 30. If the driver puts the foot down, hops on one foot or uses their arms to stay balanced, the officer will consider that a sign of intoxication.
In the HGN test, the officer has the suspect follow a moving flashlight or pen with their eyes. An involuntary jerk of the eyes can be used as evidence that the driver is intoxicated.
However, regardless of the police officer's assertions, all of these tests can be challenged in court. Each test can be affected by variables, such as an individual's medical condition, physical fitness, weight and age. For the HGN test, the officer must be properly trained and follow a strict testing protocol.
At our law firm, we are familiar with the standard field sobriety tests and their weaknesses. We thoroughly review the evidence in every case and look for inconsistencies that could call the officer's opinions into question. For more on how we can help Iowa drivers accused of OWI, please visit our web page.