The Field Sobriety tests were initially developed by the National Highway and Safety Administration (NHTSA) as a series of tests that the police could use to determine if drivers were impaired. However, these tests were initially designed to indicate impairment when a driver had a blood alcohol level of .10. The legal limit in the state of Florida is currently .08. The Field Sobriety Tests are NOT tests. They are not pass or fail and they are not graded (i.e. A, B, C, D or F). In fact, it is against the law for a police officer to refer to them as tests in court. Police officers can only refer to them as Field Sobriety Exercises (FSEs) or Field Sobriety Tasks (FSTs). Likewise, a police officer cannot testify in court that a person passed or failed them or received a specific grade for them.

This is the law because there is no standardized set of criteria that, if met, results in a DUI arrest. Studies have shown these test are not 100 percent reliable in detecting for impairment. They are merely a series exercises that a person under suspicion of DUI performs. The officer can only testify whether a person performed well or poorly on the field sobriety exercised and the basis behind their opinion.


The Field Sobriety Exercises (FSEs) are divided attention tasks. Meaning, they require a physical component and mental component at the same time. Police officers and prosecutors will try to make the argument that driving a car is a divided attention task and is, therefore, similar to the Field Sobriety Exercises (FSEs). However, the Field Sobriety Exercises (FSEs) and driving a car are nothing alike. Most people have never performed the Field Sobriety Exercises(FSEs) before, and the first time they perform them, it is on the side of the road, in front of a police car, in the dark. Meanwhile, people have been driving their car for years. To compare the two and say they are similar is blatantly misleading.

Police officers use the Field Sobriety tests because studies by the NHTSA have shown that the walk and turn was determined to be sixty-eight (68) percent accurate, and the one leg stand was determined to be sixty-five (65) percent accurate. However, these tests were not validated with people that have medical conditions, are sixty-five (65) years or older, or are fifty (50) pounds or more overweight. The police officers should use them only as a guide. Unfortunately, police officers tend to rely on them more than they should without factoring in other considerations.


There are several different ones used by police officers, but the most common ones include Horizontal Gaze Nystagmus (HGN), the Walk and Turn, the One Leg Stand, the Finger to Nose, and the Rhomberg Alphabet. There are other exercises that are used less frequently, such the Palm Pat and Hand Coordination exercise.

Horizontal Gaze Nystagmus (HGN) is sometimes also referred to as the Pen Light Task. This refers to the involuntary jerking of the eyes. There are some studies that suggest that when a person is under the influence of drugs or alcohol, their eyes will jerk involuntarily (out of the control of the person). However, when the person is not under the influence of alcohol, their eyes will not involuntarily jerk. It should be noted that there are nearly forty causes of nystagmus other than drug or alcohol. Some people even have natural nystagmus. Meaning their eyes jerk involuntarily every day for no reason. Since there are so many causes of nystagmus, officers must be specially trained in HGN to be allowed to testify in court about it. The officers must be qualified as a Drug Recognition Expert (DRE) to be able to testify about HGN. Over ninety-five (95) percent of all officers are not a Drug Recognition Experts (DREs). As such, there is a good chance that if an officer performed HGN, he will not be able to testify about it in court.

The Walk and Turn is where an officer requires a person to walk nine heel-to-toe steps in a straight line, turn around in a specific manner, and walk nine heel-to-toe steps back. This exercise can be extremely difficult for the elderly, a person with a leg or back injury, and anyone that is overweight. The mere fact that an in-shape twenty-year-old and eighty-year-old can perform the same exercise on its face is unfair. Moreover, in this exercise, the officer can and will hold even the slightest mistake against you, especially if you do not follow the instructions to the letter.

The One Leg Stand is an exercise where the person holds one leg up in a specific manner for thirty seconds. For the same reasons mentioned above with the Walk and Turn, this exercise can be extremely unfair. In certain instances, an arrest can be made even when the person holds their leg up for the entire thirty seconds.

The Finger to Nose exercise is where a person closes their eyes, tilts their head back, and touches the tip of their nose with their finger on the officer’s command. The officer will call out a hand, right or left, and the person will have to touch the tip of their nose with that hand. Usually, the officer will call out the hands in the order of left, right, left, right, right, left. Any small mistake noticed by the officer will be held against the person.

The Rhomberg Alphabet is where a person is recites the alphabet in a non-rhythmic, non-singing manner. Often times, a person will perform this exercise correctly, but an officer will state the person was swaying while they performed it. This is also an exercise that should not be performed if English is not the person’s first language or if there is any indication the person doesn’t know the alphabet.

In the end, all of the Field Sobriety Exercises (FSEs) are subjective, and it is up to the officer’s discretion whether to make a DUI arrest. A qualified DUI lawyer can thrive on cross-examining this subjectivity and the officer’s opinion.


An officer cannot ask a person to step out of the car and perform the Field Sobriety Exercises (FSEs) for no reason. However, the standard for an officer to request a person to perform the Field Sobriety Exercises (FSEs) is relatively low. It is usually met if the officer says they smelled an odor of alcohol.


The Field Sobriety Exercises are voluntary, and nobody can be required to perform them. Our clients are usually counseled to politely decline to perform them because they are subjective. A person can perform well on the Field Sobriety Exercises (FSEs) and the officer can disagree and make an arrest.


If a person refuses to perform the Field Sobriety Exercises(FSEs), the officer has a duty to tell the person that their refusal can have a negative consequence. For example, it could be used against them in court or the officer could arrest the person. If the officer does not tell the person of a negative consequence, then the fact a person refused to perform the Field Sobriety Exercises(FSEs) cannot be used against them in court. As stated above, we regularly counsel our clients to politely decline to perform the Field Sobriety Exercises (FSEs).

There is a lot of gray area with the Field Sobriety Exercises (FSEs) because they are subjective. An experienced DUI lawyer at your side is invaluable when evaluating and fighting these exercises in your case.

At Keller, Melchiorre & Walsh, we have three former prosecutors that have each handled thousands of DUI cases with field sobriety exercises. Call us at (561) 295-5825 for a free case evaluation and analysis of how you performed on the field sobriety exercises