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Virginia DUI Field Sobriety Tests

If a law enforcement officer makes a DUI arrest, he has to have a reasonable, articulable suspicion in order to make the initial traffic stop. He must establish probable cause before he places you under arrest. In other words, the officer cannot pull over a driver to “cherry pick” for drunk drivers. Rather, he or she must witness a traffic violation or other evidence of impaired driving. Furthermore, the driver cannot be arrested for DUI without evidence of impairment.

The Standardized Field Sobriety Tests developed by the National Highway Traffic Safety Administration (NHTSA) are designed to provide law enforcement officers with a tool to confirm the suspicion of impairment and to give them probable cause for a DUI arrest.

If you have been arrested for DUI following a failed sobriety test, it is helpful to have a defense attorney who is a member of the National College for DUI Defense and one who is trained in the administration of the Standardized Field Sobriety Tests.

Analyzing a sobriety test is subjective, and an officer’s failure to properly administer or evaluate a field sobriety test could result in an unlawful arrest and dismissal of the charge. Consult an experienced

Consult an experienced Virginia DUI lawyer for more information.

NHTSA Standardized Field Sobriety Tests

understandingvafieldsobrietytestAccording to the National Highway Traffic Safety Administration (NHTSA), “The Standardized Field Sobriety Test (SFST) is a battery of three tests administered and evaluated in a standardized manner to obtain validated indicators of impairment and establish probable cause for arrest.”

This battery consists of three specific tests, each intended to expose impairment through analysis of a subject’s performance. Following are the three tests of the SFST:

  • Horizontal Gaze Nystagmus (HGN)
  • One-Leg Stand (OLS)
  • Walk-and-Turn (WAT)

These tests are intended to reveal problems with coordination that are often associated with impairment by drugs or alcohol; however, if medical conditions and other factors are not considered in the evaluation of the test, a person could “fail” a field sobriety test even without intoxication.

Horizontal Gaze Nystagmus (HGN)

In the HGN test, an officer evaluates the smoothness and fluidity of a subject’s horizontal gaze nystagmus, or the way the eye tracks from side to side. In general, an unimpaired person will be able to smoothly follow a stimulus with his or her eyes; however, in an impaired subject, the movement of the eyes will likely be jerky.

During the HGN test, an officer will ask a subject to follow an object, such as a pen or small flashlight, with his or her eyes as the object moves from side to side. The officer will then look for signs of impairment which may include:

  • The inability of the subject’s eye to smoothly follow the stimulus;
  • Nystagmus begins before the eye is 45 degrees from the object’s starting point;
  • The involuntary jerking of the eye (nystagmus) occurs for four seconds or more at the furthest peripheral angle.

If the officer observes these signs of impairment, the driver will likely be arrested under suspicion of DUI. The NHTSA claims that the HGN is effective in determining impairment in 88 percent of suspects.

One-Leg Stand (OLS)

Another measure of balance and coordination, the One-Leg Stand, requires a subject to stand on one foot with the other raised six inches above the ground. During the one-leg stand, the subject must count by thousands (“one thousand one, one thousand two,” etc.) for 30 seconds before the officer asks the subject to lower the raised foot to the ground. Indicators of impairment include:

  • Noticeable swaying or difficulty maintaining balance.
  • The subject’s arms are raised more than six inches from his or her side to help maintain balance.
  • The subject hops on one foot to maintain balance.
  • The subject lowers his or her foot to the ground before the officer instructs him or her to do so.

According to a 1998 study published by the NHTSA, 83 percent of test subjects who demonstrate two of the above indicators will have a BAC of 0.08 percent or greater.

Walk and Turn (WAT)

The Walk and Turn test is intended to demonstrate a lack of balance and coordination associated with impairment by drugs and/or alcohol. It is also a “divided attention” test that requires a subject to listen to directions while performing a task. During this test, the subject will be asked to take a number of heel-to-toe steps along a straight line before turning on one foot and returning to the starting point in the same fashion. Signs of impairment include:

  • The subject beginning the test before instructions are completed.
  • The subject cannot maintain balance while listening to instructions.
  • The subject does not walk heel-to-toe, leaving a space of more than ½-inch between the feet.
  • The subject stops walking before the test is completed.
  • The subject cannot walk in a straight line.
  • The subject does not turn on one foot, does not turn on the line, or is off-balance in the turn.
  • The subject takes more or fewer than the steps required.
  • The subject raises his or her arms more than six inches from their sides in order to maintain balance.

The NHTSA considers the test to be effective in determining DUI in 79 percent of those tested who exhibit two or more of the above signs.

Virginia Field Sobriety Test Defenses

Despite NHTA’s national standards, remember that field sobriety tests are not universally accurate. If the officer has not been trained to administer the test properly, or if the test is not given in an appropriate environment (level, dry ground with adequate lighting), the results can be flawed. In such instances, your field sobriety test results may be found inadmissible in court, which sometimes means the charge against you must be dismissed.

This is why drivers should carefully consider whether to respectfully decline any SFST. It is their right, and they should be mindful if they have any condition that could give the police officer a false impression.

One important point to remember is that the officer administering the test has made an initial judgment that the driver might be under the influence of some form of intoxicant.  With this pre-formed judgment, it is possible the officer could misread clues simply because he or she might be looking for something that isn’t really there.  The results of the SFSTs are compromised if the officer deviates from the standardized procedures, and mistakes are easily – and often – made.

Additionally, during their training, memorizing all the details of how to properly administer field sobriety tests is just one of many procedures that officers must accomplish.  So, it is not unusual for them to forget details of administering SFSTs.  When that happens, it’s usually done unintentionally.

However, the NHTSA training manual is clear that any deviations from standard testing procedures compromise the validity of the tests.  But mistakes are still mistakes, and the law cannot allow mistakes in procedure to compromise evidence.

Remember, failing a field sobriety test does not always mean you were intoxicated.  Unlike blood and breath alcohol testing, sobriety tests are highly subjective.  There’s really no scientific way to determine whether or not you were actually under the influence of drugs or alcohol at the time the test was administered because they’re based on personal subjectivity rather than factual data.

DUI Defense Representation

Clearly, field sobriety tests are not completely accurate in determining alcohol impairment—even the NHTSA indicates room for error in these tests. If you are pulled over and suspected of DUI, it is important that you understand that these tests are intended to provide probable cause for an arrest. In other words, they are used to confirm suspicion, not to exonerate you.

You have the right to refuse field sobriety tests. You will likely be arrested for DUI anyway. But the officer will not have confirmation of his or her suspicions, which could later be used to demonstrate an unlawful arrest without probable cause.

To learn more about the DUI defense strategies which may be effective in your specific case, call today for a free, initial case consultation.