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Standardized Field Sobriety Tests

The following is an excerpt from an interview with Maryland DUI lawyer Kush Arora, where he answers questions about field sobriety tests.

What are Standardized Field Sobriety Tests (SFSTs)?

When it comes to field sobriety tests, there is a set of rules that are outlined by the National Highway Traffic Safety Administration (NHTSA). Before standardized sobriety testing, it was more difficult for officers to determine if they had enough probable cause to arrest someone for driving under the influence. For example, if someone’s vehicle was stopped and the officer found that there was enough of a basis to suspect that the driver might be under the influence of alcohol based on indications like the odor of alcohol, slurred speech, bloodshot watery eyes, or an open container in the vehicle, that was not enough for an officer to deduce that a person was driving under the influence of alcohol.

The officers had to develop some kind of an objective to use to decide whether or not there is probable cause to place somebody under arrest, take them to the station, and ultimately give them a chemical breath test that’s admissible in court. The Standardized Field Sobriety Tests (SFSTs) are the way that an officer achieves that objective standard. The standard is objective because the tests are standardized, meaning the test that somebody is taking in Maryland is the same as the test somebody is taking in Virginia, Florida, New Mexico, California, or anywhere else in the United States.

These tests are regulated and mandated by the NHTSA, which is funded by the federal government and gives officers the training and guidelines that they need to administer field sobriety tests and record certain results. The results have been scientifically studied by the NHTSA and give an officer different clues to demonstrate that the person was driving under the influence of or driving while impaired by alcohol.

Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus (HGN) test is usually the first test administered by a police officer. This is a test in which the officer asks the driver to follow a stimulus, such as a flashlight or a pen, with their eyes. The stimulus is usually followed from left to right or up and down. This particular test is used to observe a couple of things. It measures whether or not the person is able to follow instructions the officer is giving, because if someone is unable to follow the simple instructions of the test, they might be impaired. The officer is also searching for nystagmus. Nystagmus is an involuntary jerking of a person’s eyes at a certain degree.

Usually, a person who has not consumed any alcohol is able to track a stimulus smoothly without any interruption, but when a person has even a small amount of alcohol in their system, they display this involuntary jerking, also called nystagmus, and that serves as a clue to the officer that the person might have some alcohol in their system. This test is a standard one that is administered by officers. However, courts are moving away from the reliability of this test because despite the fact that alcohol does impact a person’s ability to display nystagmus, there are several conditions that are neurologically based that can also impact a person’s ability to perform this test. Therefore, the test is deemed to be somewhat unreliable and many courts have stopped using it for a purpose other than to say that a person has some alcohol in their system.

One-Leg Stand Test

The other two tests are divided attention tests. One of them is called the One-Leg Stand (OLS), where an officer asks an individual to stand on one foot and raise the other off the ground for a particular period of time. Usually, the person has to keep their foot about six inches off the ground and either the officer or the individual counts out loud while keeping their arms at their sides. The most important thing the officer is looking for is balance, but an ability to follow the instructions that the officer is giving is also a component. A person who puts their foot down, sways from side to side, or raises their foot for balance might be displaying intoxication or impairment.

Walk-and-Turn Test

The final, and perhaps the most complicated, test that an officer administers under the NHTSA rules is the Walk-and-Turn (WAT) test. This test requires an individual to listen to instructions from an officer, take nine steps heel-to-toe in one direction, turn around in a particular fashion, usually by taking a series of small steps, and then take nine steps back the other way while walking on an imaginary or a printed line on the road. This test is the most complicated because there are up to eight clues that an officer is looking for to determine whether or not a person is under the influence of alcohol, including the ability to follow instructions, walk heel-to-toe for each step and in both directions, stay balanced, take a proper turn, stay on the line, and take the correct number of steps. Because of how many tasks there are, including the person keeping their arms at their sides while they’re doing this test, there are various clues that could demonstrate whether or not probable cause exists to place a person under arrest for driving under the influence of alcohol.