Explaining Field Sobriety Tests in Arizona

Common Field Sobriety Tests

If a police officer stops you and believes that you are driving under the influence (ARS 28-1381), they may ask you to complete field sobriety tests. There are five different tests that are commonly given to people in Arizona, only three of which are standardized. When a DUI lawyer works with a client who is charged with a drunk driving offense, one of the things they will do is review any field sobriety tests to which their client submitted. Here are some common questions and answers about field sobriety tests often asked of a Phoenix DUI lawyer.

1. What are field sobriety tests?

Field sobriety tests are a battery of assessments derived from those developed by the National Highway Traffic Safety Administration, or NHTSA. Of the tests that are commonly given in Arizona, only three are standardized. Standardized field sobriety tests, or SFSTs, are those that are considered to be reliable according to the NHTSA. The SFSTs include the following:

• Horizontal gaze nystagmus, or HGN
• The walk-and-turn
• One-leg stand

In the HGN, the officer uses a pen and, while moving it back and forth, asks you to follow it with your eyes. While you do this, the officer will watch your eyes for a slight jerking motion known as nystagmus at specific visual degrees. These are called "clues." There are three per eye for a total of six possible clues.

The walk-and-turn involves the officer asking you to walk down a straight line using nine heel-to-toe steps. At the end, they have you turn and walk back to them, again in a straight line with nine heel-to-toe steps.

In the one-leg stand, the officer will ask that you stand with your hands at your sides while you lift one leg six inches off of the ground. They will ask you to estimate 30 seconds while you hold it in the air. Failing this test can include putting your foot down, incorrectly estimating 30 seconds, hopping or even raising your arms out further than 6 inches from your sides. 

2. When can they be requested?

If an officer believes that you may be driving under the influence, they can ask you to take field sobriety tests. Your DUI lawyer Phoenix will review the officer's reason for stopping your vehicle as well as any other indicators that would amount to reasonable suspicion under the law.

3. Can you refuse field sobriety tests?

In State ex rel Verburg vs. Jones, the Arizona Court of Appeals held that people do not have the right to refuse roadside tests. Practically, this means that if you do refuse them, then the prosecution can tell the jury that you did so. A refusal to do roadside tests does not provide conclusive proof that you were, in fact, driving drunk, however. If you do refuse, you will not face additional penalties for doing so, unlike when people refuse to take a breathalyzer test. 

If you are ever in a situation where you are being asked to perform field sobriety tests, your best decision is to immediately request to speak to a lawyer. 

4. Are the tests accurate?

While the NHTSA claims that the SFSTs are highly reliable, there are many reasons people who are sober will fail them. Some people have various eye conditions that give them a natural nystagmus, such as glaucoma or others. Others might have back or leg problems that make it nearly impossible to walk heel-to-toe in a straight line. There are also many people who have conditions that cause balance problems, such as inner-ear infections and others.

The National District Attorneys Association, or NDAA, has created a report called the “Admissibility of Horizontal Gaze Nystagmus Evidence”, which also discusses the accuracy of HGN.

When you are stopped by an officer and asked if you'll consent to roadside sobriety tests, remember that you cannot be forced to do so. If you politely refuse, it may help your case by lessening the amount of evidence the prosecutor will have to use against you. If you are charged with a DUI, finding the best DUI attorney in Phoenix, AZ may help you to defend against your charges.