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If you were pulled over and asked to complete a series of field sobriety tests, you’re probably worried about your future. The criminal penalties for a DWI can be harsh, and the collateral consequences on your life can be even more concerning. But you don’t have to deal with this situation alone. Even if you failed standardized field sobriety tests, there is a chance that a skilled DWI defense lawyer can have your charges reduced or thrown out. Call Swate Attorney at Law for more information about how we can help you.


In the mid ’70s the Stockton, California city conducted a survey regarding DWI arrests. Thereafter, the Stockton Police started conducting intensive DWI enforcement and recording the results. They tried to develop ‘programs’ to detect intoxicated drivers.

Thereafter, other agencies began conducting studies, which led in time to the creation of the SFSTs by the National Highway Traffic and Safety Association (NHTSA). The SFSTs were adopted by every State in the United States, including Texas through the Texas Department of Transportation and the Commission on Law Enforcement Officer Standards and Education.

It is now the goal (and usually the requirement) that every law enforcement officer become certified as a SFST Practitioner. The purpose is to equip the officer to be able to better determine if a citizen is intoxicated.


There are two ways to determine legal intoxication: a ‘scientific’ test (breath or blood) (please see the pages on Breathalyzer Test and Alcohol Blood Test), or the classic standard of ‘having lost the normal use of mental or physical ability’. If the citizen refuses to perform a ‘scientific’ test, the officer must rely totally on the citizen’s appearance and performance on the SFST. It is then an officer’s subjective decision whether the citizen has actually lost the normal use. Therefore, this is the purpose of the SFSTs.

I call the SFSTs the ‘balance tests’, for that is exactly what they are. But they are not fair. Actually, if analyzed, NHTSA designed these tests for failure. (Even by their standards the tests are only 77% accurate. So, about one in four will be a citizen wrongfully arrested.) There is more detail on other pages, but in a nutshell a citizen is required to do abnormal balance functions for the officer to determine the citizen’s normal behavior! While doing the tests, the citizen is required to watch his or her feet. This does two things to one’s internal ‘gyroscope’…sense of balance.

First, by watching his or her feet, the eyes are taken off the horizon, which limits a person’s depth perception, thereby increasing ‘vertigo’, or dizziness.

Second, this same process tilts the head down. Normally, throughout the day, we keep our heads level. Our inner ear has fluid in it to stabilize our ‘vertigo’, or balance. When tilted down, that fluid is ‘upset’, which again increases ‘vertigo’, or imbalance.

There are several other factors which will affect the ‘accuracy’ of these tests which would be better discussed together. Call me and I’ll tell you more about the SFSTs.


Although there are multiple different kinds of field sobriety tests, there are three primary tests that are commonly used by police officers.


The horizontal gaze nystagmus (HGN) test is one of the field sobriety tests that looks at the movement of your eye. “Nystagmus” is the jerking or bouncing activity of the eye as it follows an object. A normal, healthy eye will smoothly follow an object from right to left and up to down. However, a person who is impaired by drugs and/or alcohol may show more pronounced jerking or bouncing of the eye. There are many other conditions, medications, and other causes that will produce a stronger nystagmus.

When a police officer decides to administer field sobriety tests, they usually ask you to exit your car and stand at the side of the road. An officer should move you away from other lights and sounds that may distract you. Police officers administering an HGN test may ask about any conditions that may impact the outcome of the test. The officer may hold an item, such as a pen or stylus, around a foot from. Your face. You will be asked not to move your face, but to follow the item with your eyes.

While conducting the HGN test, the officer will be looking for the following:

If you fail an HGN test, that does not mean that you will be convicted of a DWI. There are many reasons that you may have had pronounced nystagmus, including health conditions, contacts, and more.


Another one of the common field sobriety tests is the walk-and-turn test. This test requires you to stand heel-to-toe and walk a straight line, then return walking the same line. Oftentimes, an officer will have you count aloud as you walk the line. The walk-and-turn test is supposed to tell the officer if your mental and physical abilities are impaired.

During a walk-and-turn test, the officer may ask you to follow several directions, including:

The officer will be watching you as you complete the walk-and-turn test. If you step off the line or miss a heel-to-toe step by more than a half inch, it may indicate intoxication. If you pause your steps or stop completely, the officer may also make note of your behavior. Failing to follow any of the directions given by the officer may also indicate intoxication.

If you fail a walk-and-turn test, you can still avoid a DWI. There are many health conditions that affect this test, such as an ear infection and over the counter medications.


The one-leg stand test is one of the field sobriety tests that can indicate you are intoxicated by drugs or alcohol. However, many other causes can result in failing this test. The test involves you standing straight with one foot lifted around six inches off the ground. You should not be asked to stand in this position or longer than 30 seconds.

When asked to complete a one-leg stand test, you will also be asked to look at your raised foot. You must keep your arms at your side and keep the foot raised until you are directed to stop. You may also be asked to count. While standing, the officer will be looking for swaying or use of your arms for balance. If you hop, stumble, or put your foot down, the officer may think you are intoxicated.

Field sobriety tests such as the one-leg stand test are extremely flawed. You may have an inner ear infection or just find it difficult to balance. If you are wearing shoes with heels or uncomfortable clothing, your test results may be inappropriate. A DWI defense lawyer can help you fight field sobriety test results.


It’s important to work with an attorney who is familiar with field sobriety tests and can help you avoid the harshest penalties for a DWI. Contact Swate Attorney at Law today.