What is a Field Sobriety Test in Arizona?

Arizona traffic officers have several ways to determine if a driver might be operating an automobile while under the influence of alcohol or drugs. Such initial screenings are rooted in law, physiology and training. As soon as an officer observes a traffic infraction such as a faulty brake light, he or she has legal grounds to conduct a traffic stop. The officer will ask the driver questions if it appears as though he or she is impaired. The officer can also invite the driver to participate in a field sobriety test.

Though drivers can refuse to comply with an invitation to participate in such a sobriety screening, there is the potential for the refusal to lead a suspension of the driver’s license for a year. If this is the driver’s second offense, his or her license can be suspended for upward of two years.

Pre-arrest Sobriety Testing

A driver who is stopped based on the suspicion of driving while impaired will be subjected to multiple field sobriety tests. The police offer will provide nuanced verbal instructions that the driver is to adhere to during the tests. There is a good argument to be made that the driver should politely refuse to participate in such pre-arret field sobriety tests.

As an example, a driver might be asked to perform the pre-arrest sobriety test dubbed “walk and turn” in which he or she is to take nine steps forward, putting the heel in front of the toe, then nine steps backward along a straight line. The suspect is to verbally count the steps as they are taken. Such a test gauges the suspect’s memory recall and muscle control. If the officer observes the suspect can’t properly balance, begins walking too soon, stops walking or steps to the side, it is an indication the driver might be drunk or high.

The One Leg Stand

The one leg stand test requires the suspect to stand with his or her feet together and raises a leg half a foot off the ground while looking at that foot with the arms dangling at the sides of the body. The suspect is to hold this position while listening to the officer’s instructions. The test gauges whether the suspect is sober enough to follow the officer’s instructions, properly balance and count verbally until the police officer says it is time to stop.

This test has the suspect standing on a single leg for 30 seconds. If the driver hops, requires the use of the arms to maintain balance, sways or lowers the raised leg, it is a sign he or she is above the legal BAC limit.

The HGN Test

HGN is an acronym short for horizontal gaze nystagmus. Nystagmus is the involuntary movement of the eyes. A police officer will move a pen left and right a couple inches in front of the driver’s eyes, gauging whether he or she follows its movement properly. If the officer sees the suspect has involuntary eye movement and concludes the driver is impaired, he or she is tasked with determining if there is the probable cause necessary to proceed with compiling incriminating evidence. The failure of this test sets the stage for the police officer to perform a blood test or use a breathalyzer to test the suspect’s breath.

Are Field Sobriety Tests Reliable?

Arizona’s DRE program, short for Drug Recognition Experts, trains police officers to recognize the signs of inebriation caused by the consumption of alcohol or drugs. Such DRE officers can be called to the site of a traffic stop by a police officer who has not passed through similar training. The reliance on a DRE officer bolsters the state’s DUI charge all the more.

However, field sobriety tests are not flawless. A savvy attorney will pick apart these tests, highlighting their weaknesses and flaws. As an example, an individual who sits at a desk all day and has poor balance due to the lack of standing time will find it inherently difficult to stand on one leg during a field sobriety test. Furthermore, a neurological condition might cause the suspect to fail the eye test. Add in the fact that the suspect’s nervousness might prevent him from passing the field sobriety test and there is even more reason to fight a DUI charge resulting from a failed pre-arrest field sobriety test.