Omaha DUI Lawyers Explain Field Sobriety Tests

Jan 24, 2018 | By Petersen Criminal Law | Read Time: 4 minutes |

No one expects to be the subject of a traffic stop turned into a driving under the influence (DUI) investigation. In fact, most people who are ultimately arrested and charged with DUI are otherwise law-abiding citizens who had a momentary lapse in judgment when they got behind the wheel after consuming alcohol. Because you don’t think you will ever be stopped, you will likely not know how to handle the situation if it does occur. Most people who find themselves the target of a DUI investigation are unsure what they should and shouldn’t do, particularly when the officer asks them to step out of the vehicle and perform a series of “Field Sobriety Tests.” To help you feel prepared, should you be asked to perform them, the Omaha DUI lawyers at Petersen Law Office explain Field Sobriety Tests (FSTs).

Why Are Field Sobriety Tests Administered?

The results of FSTs are not admissible as evidence that a motorist was driving under the influence at a trial. Why do police officers ask motorists to perform the tests then? Law enforcement officers ostensibly ask a motorist to perform FSTs so that the officer can determine if the motorist appears to be driving under the influence. In reality, however, most of the time an officer has already concluded that the motorist is intoxicated. The FSTs, therefore, are used predominantly as a way for the officer to achieve the probable cause necessary to make an arrest. Although the results of an FST cannot be used as evidence at trial, that same result can be used to establish probable cause for an arrest.

What Are Field Sobriety Tests?

Not all that long ago, law enforcement officers used a seemingly never-ending number of tests to determine if a motorist was under the influence. Many of these tests had absolutely no basis in science and even less objective criteria by which to determine if a subject passed the test. Not surprisingly, this led to much confusion and numerous attacks by defense attorneys on the validity of the tests. In response, the National Highway Transportation Safety Administration, or NHTSA, officially approved three FSTs, now referred to as the “standardized” FSTs because there are guidelines for performing and evaluating the tests. Although the law does not prevent an officer from using other tests, most law enforcement agencies now mandate the use of these three Standardized Field Sobriety Tests which include:

Horizontal Gaze Nystagmus test — according to the NHTSA, “Horizontal Gaze Nystagmus is an involuntary jerking of the eye that occurs naturally as the eyes gaze to the side. Under normal circumstances, nystagmus occurs when the eyes are rotated at high peripheral angles. However, when a person is impaired by alcohol, nystagmus is exaggerated and may occur at lesser angles. An alcohol-impaired person will also often have difficulty smoothly tracking a moving object.” The HGN test involves the officer using a penlight, or similar instrument, and asking the subject to track it as it is moved from the center of the subject’s field of vision over to one side and back. When administered properly, and graded objectively, the HGN test can be relatively accurate at detecting impairment. The examiner looks for three indicators of impairment in each eye:
- if the eye cannot follow a moving object smoothly
- if jerking is distinct and sustained nystagmus when the eye is at maximum deviation
- if the angle of onset of jerking is prior to 45 degrees of center.
Walk and turn – a subject is required to take nine steps, heel-to-toe, along a straight line. After taking the steps, the suspect must turn on one foot and return in the same manner in the opposite direction. The examiner looks for eight indicators of impairment:
- if the suspect cannot keep balance while listening to the instructions
- begins before the instructions are finished
- stops while walking to regain balance
- does not touch heel-to-toe
- uses arms to balance
- steps off the line
- takes an incorrect number of steps
- makes an improper turn.
One leg stand – a subject must stand with one foot approximately six inches off the ground and count aloud by thousands until told to put the foot down. The officer times the subject for 30 seconds. The officer looks for four indicators of impairment including:
- swaying while balancing
- using arms to balance
- hopping to maintain balance
- putting the foot down.

Do I Have to Perform the Field Sobriety Tests?

No. You are not required to perform the FSTs and there are no adverse consequences for refusing the tests, unlike refusing a chemical test. The reality is that most officers have already made up their mind to make an arrest before the first FST begins. Therefore, agreeing to perform the tests accomplishes nothing more than providing the officer with the probable cause necessary to make an arrest. Unless you are absolutely sober, have no physical or mental conditions that could impair your ability to perform the tests, and are certain your nerves will not cause you to fail, it is in your best interest to respectfully decline to perform the tests.