Designed by the National Highway Traffic Safety Administration (NHTSA), standardized field sobriety tests are often used by law enforcement agents at a DUI stop to determine if an arrest should be made. Michigan police officers may use the one-leg stand, the walk-and-turn, and the horizontal gaze nystagmus tests to decide if there is probable cause for a drunk driving arrest. Both the one-leg stand and walk-and-turn tests are known as divided attention tests, which means that they measure both your physical performance and ability to understand and follow instructions.
The one-leg stand test consists of an instruction and performance stage. During the instruction phase, the officer will ask you to stand with your feet together and arms at your side while he or she explains and demonstrates how you should perform the test. After confirming that you understand the directions, you will be instructed to stand on one leg while raising the other six inches off the ground and counting one-one thousand, two-one thousand, and so on until asked to stop.
The officer will look for four clues during the test:
If you exhibit two out of four clues, you can be arrested for OWI.
The walk-and-turn test also includes an instruction and performance stage. To perform this test, you will be asked to take nine heel-to-toe steps on an imaginary line, pivot, and then take nine steps back while counting each step aloud. There are eight clues for this test, which include:
If the officer sees two of these clues, you may meet the criteria for arrest.
The horizontal gaze nystagmus test measures the jerking of your eyes, which become more pronounced when a person is intoxicated. To administer the test, an officer will ask you to keep your head still and follow a small stimulus with your eyes. The officer will look for a lack of smooth pursuit, distinct jerking while your eyes are at maximum deviation and the onset of jerking before your eyes reach 45 degrees. If you exhibit these clues in either of your eyes, the officer can place you under arrest.
Nystagmus can be an indicator of alcohol or drug impairment, although it is also associated with several medical conditions, including:
Other legal substances, such as aspirin and caffeine, can also cause nystagmus. Additionally, a small percentage of people have naturally occurring nystagmus.
Standard field sobriety tests are standardized, which means there is one way to instruct, one way to demonstrate, one way to score, and one way to perform. The standardized method is to ensure reliability and accuracy. The National Highway Traffic Safety Administration implemented these tests based upon studies concluding reliability or correlation of subjects under the influence or impairment of alcohol, and the number of clues associated with the particular test.
If an officer deviates from standardized instruction or demonstration or the scoring, it compromises the reliability of the conclusion. We, our attorneys at the Barone Defense Firm, have all completed the same training for standard field sobriety tests that officers receive, and we know exactly how it’s supposed to be done.
Now if we contrast that with other common field tests, the significant difference is reliability. ABCs, the counting test, finger-to-nose have absolutely no scientific and no correlation to impairment of alcohol. They have, however, been used by law enforcement for so long that it continues today, almost by tradition versus any scientific reliability.