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Field Sobriety Tests

Field Sobriety Tests

What should I do if I’m asked to take field sobriety tests?

There is a wide-range of field sobriety tests (FSTs), including heel-to-toe, finger-to-nose, one-leg stand, eye test called “horizontal gaze nystagmus” test, alphabet recitation, modified position of attention (Rhomberg), fingers-to-thumb, hand pat and others. In Arizona, most officers will use a set battery of six common tests.

Unlike the chemical test, where refusal to submit may have serious consequences, Arizona DUI law does not require you to take any of the Field Sobriety Tests (FSTs). The reality is that officers have usually made up their minds to make a DUI arrest when they give the FSTs; the tests are simply additional evidence which the suspect inevitably “fails.” Thus, in most cases a polite refusal may be appropriate and smart.

Why did the officer make me follow a penlight with my eyes to the left and right?

This is the “horizontal gaze nystagmus” test, a relatively recent development in DUI investigation. The officer attempts to estimate the angle at which the eye begins to jerk (“nystagmus” is medical jargon for a distinctive eye oscillation). If this occurs sooner than 45 degrees, it theoretically indicates a blood-alcohol concentration over .05%. The smoothness of the eyes tracking the penlight (or finger or pencil) is also a factor, as is the type of jerking when the eye is as far to the side as it can go.

This field sobriety test has proven to be subject to a number of different problems, not the least of which is the non-medically trained officer’s ability to recognize nystagmus and estimate the angle of onset. Because of this, and the fact that the test is not accepted by the medical community, it is not admissible as evidence in many states. Unfortunately, Arizona allows the test as evidence and it is widely used by law enforcement to get DUI convictions. We believe it is one of the least reliable tests and are very successful in discrediting this test in court.

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