Arizona Sobriety Tests – Should you take them?

When talking to people in Arizona about DUI matters, I’m often asked about Standard Field Sobriety Tests, also known as SFSTs.

The most commonly asked question is, “should I take these tests?”. Usually I advise No. In Arizona, the SFSTs are not required by law. They are voluntary and, more often than not will result in “cues” that show impairment, even if you are completely sober.

Horizonal Gaze Nystagmus (HGN) test

Here’s what usually happens. If an Arizona police officer stops you for a traffic infraction, they will often ask you if you are willing to take some tests, so they can be sure you are safe to drive. The tests are the SFSTs, which include a Horizonal Gaze Nystagmus (HGN) test. In this test, the officer will use a pen, finger or other object and ask you to follow that “stimulus” with your eyes. They are primarily looking for your eyes to “jump”, which may or may not be an indication of alcohol impairment. They will likely also count it against you if you move your head to follow the object. Many Arizona drivers think that because they can see the stimulus, or follow it, they have passed the test. In reality, that is only a small part of the test. The officer is looking at your eyes to see if there is any nystagmus. Nystagmus, is the involuntary jerking or bouncing of the eyeball.

Other Standard Field Sobriety Tests

In Arizona, the HGN test will usually be followed by other SFSTs like a Walk and Turn, One Leg Stand, and others. These are designed to give cues of impairment. If you have a few cues, you will likely be arrested. To say these tests are only to make sure the driver is able to drive is a real misstatement. In reality, these tests also are used to compile evidence of impairment, and help the officer make s decision about whether he will arrest the driver.
Many of the tests are designed contrary to natural movement. For instance, since you were a child you’ve likely walked a straight line with ease. You put one foot in front of the other, arms spread to assist in balance and walk forward pretending you were a tight-rope walker. However, in SFSTs, you need to put heel to toe and are instructed to keep your arms at your side. If you raise your arms, the police will count that against you. If your feet are more than .5 inches from heel to toe, the police will count that against you. These are not traditionally things that we associate with impairment. So, it’s possible to be sober, or under the legal limit and fail these tests.

Many people are certain they did well or “passed” the SFST, but police officers don’t tell you what will be counted against you and record cues that make it appear as a failure. Officer’s rarely report things a driver did well. There are many reasons besides impairment that one might present with cues. If one is overweight, non-athletic, wearing bifocals, has previous injury or joint replacement, is elderly, hard of hearing or many other reasons, it’s likely one will present with cues of impairment while completely sober.

In some Arizona jurisdictions, law enforcement officers have body worn cameras that will record video of your performance on the SFSTs. Not all police have body cameras. Cities like Scottsdale and Mesa are more likely than other cities to have the SFSTs recorded by body cameras.
Generally, if the officer does not have video, you probably should not take the tests. Any cues or errors reported by the officer will likely stand as there is no evidence to refute the officer’s findings. If there is video, and you perform very well on the SFSTs, you could be assisted by having taken them. If you have had a few drinks, this is likely not worth the gamble.


While it’s tempting to comply with the officer’s request, so you don’t appear to be uncooperative, there is too much risk involved to take a test that is not legally required. In Arizona, Failure or refusal of the tests is admissible, but you can and should politely exercise your rights and decline these tests, under most circumstances.

If you have or have not submitted to SFSTs and were arrested for DUI in Arizona, I can help. I have years of experience in reviewing video and reports that indicated failure of the SFST and won cases in which the police indicated my client failed. I was able to point out that the officer made mistakes, gave incorrect or confusing instruction or other problems. If you’ve been arrested and charged with an Arizona DUI, give me a call for a free consultation. I can help.

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