In Michigan, police officers are trained to use Field Sobriety Tests “SFST” to detect impairment during a drunk driving investigation. These divided attention tests are used to determine whether there is probable cause to arrest someone for DUI/OWI. These tests were created by the National Highway Traffic Safety Administration (NHTSA). The three standard tests include:
1. Horizontal Gaze Nystagmus (HGN)
This test involves an officer checking the eyes of the suspected drunk driver to determine if nystagmus occurs. Nystagmus is an involuntary jerking of the eye, typically a side effect of alcohol intoxication. The officer must conduct this test exactly as he was taught, otherwise the test results are meaningless.
The officer moves an object smoothly (pen or finger) across the person’s field of vision. They are looking for “clues” in three separate stages. One of the clues is distinct and sustained nystagmus at maximum deviation. This test is often subject to dispute due to an officer’s failure to properly perform the test. However, if conducted properly, this test gives the most correlated result to impairment.
2. Walk-and-Turn (WAT)
People are most familiar with the walk-and-turn test. A person is told to take nine heel-to-toe steps, turn around, and take nine heel-to-toe steps back. All of this must be accomplished with arms at the sides and staying in a straight line. Officers are looking for 8 “clues” on this test.
The police are notorious for exaggerating someone’s results on these leg stand tests. A thorough review of the dash-cam video can show defects in the instructional phase of this test. Also, it can be great for showing the officer “misremembered” something. If someone exhibits less than 2 clues on this test, it indicates their BAC is not over .08.
3. One-Leg Stand (OLS)
Even on our best days, few people can pass this test sober. A person is instructed to raise a leg of their choosing six inches off the ground and hold it until told otherwise, usually 30 seconds. Essentially, they are standing on one foot. The police are looking for 4 clues here.
Usually, a person will put their foot down early or “hop/sway”. It takes very little to “fail” this test, as two clues gives the officer some evidence that your BAC may be over .08.
Challenging the SFSTs
While these tests may seem easy, numerous outside influences can cause a false positive. People with head injuries are set up to fail on the HGN. Individuals with back/leg/knee problems will struggle with the WAT and OLS tests. It is crucial to give your attorney a thorough history of your medical conditions to provide them viable defenses.
Most importantly, it is important to remind the judge/jury that the officer was taught to do these tests properly during the academy. This could have occurred 5,10 or even 15 years prior. A dedicated OWI attorney takes an SFST class at least once every two years. Therefore, picking apart their instruction, evaluation, and documentation of the SFSTs can lead to suppression of the results and dismissals of the case.
It should be noted that you are NOT required to participate in these field sobriety tests. There is no penalty for refusing to walk the line or lift your leg. An officer will usually then administer a preliminary breath test (“PBT”) roadside. If your breath sample is .08 or above, you will be arrested for OWI. You may also refuse the PBT, which carries only a civil infraction and a small fine.
Essentially, your performance on the SFSTs and the PBT are the cornerstones for the evidence against you. If you agree to perform the tests, you must hire an attorney who is qualified to evaluate the officer’s administration of the tests. Remember, these tests are set up to make you fail. Fighting back against their evidentiary value is the key to winning your case.