Contact Me for a Free Consultation 703-219-8220

Field Sobriety Tests

Fairfax DUI Lawyer explains Field Sobriety Tests in Virginia and how courts use them

Introduction to Field Sobriety Tests

Field Sobriety Tests (FSTs) are a series of exercises used by law enforcement officers to determine if a driver is under the influence of alcohol or other substances. They are designed to assess a person's physical and cognitive abilities, which may be impaired due to intoxication. In this article, a Fairfax DUI lawyer explains the different types of FSTs, how they are administered, and how Virginia courts use them in DUI cases.

Do I Have To Take Field Sobriety Tests?

No, there is no Virginia law that requires drivers to perform field sobriety tests. You can, and should, decline to take the tests. Further, while there are national standardized tests, Virginia itself has no set of standardized tests. Meaning, officers should, but are not required to, follow the national standards.

Types of Field Sobriety Tests

There are three standardized FSTs that are commonly used by law enforcement officers. These tests have been approved by the National Highway Traffic Safety Administration (NHTSA) and are considered reliable indicators of impairment when administered properly. However, failing a test does not mean a person is intoxicated. There are many reasons why someone could make a mistake while performing these tests other than alcohol. Medical conditions, injuries caused by a crash, and other factors can effect a person's ability to perform the tests.

Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus (HGN) test evaluates the involuntary jerking of the eyes as they move side to side. An officer will ask the driver to follow a stimulus (usually a pen or flashlight) with their eyes while keeping their head still. The presence of nystagmus, or jerking movements, may indicate intoxication. This test is generally not admissible in Virginia courts. However, a persons ability to follow the test instructions is admissible.

Walk-and-Turn Test

The Walk-and-Turn (WAT) test requires the driver to take nine heel-to-toe steps in a straight line, turn around, and take nine more steps back to the starting point. This test evaluates balance, coordination, and the ability to follow instructions. Errors, such as stepping off the line or not touching heel-to-toe, can be signs of impairment.

One-Leg Stand Test

In the One-Leg Stand (OLS) test, the driver is asked to stand on one foot and count aloud for 30 seconds. Officers look for signs of impairment, such as swaying, hopping, or putting the raised foot down.

How Field Sobriety Tests are administered

Officers administering FSTs must follow specific guidelines to ensure the tests are conducted fairly and accurately. If the tests are not administered properly, their reliability may be called into question. Any change to the tests or errors in their interpretation can bring into question the results.

Probable cause and Field Sobriety Tests

Before administering FSTs, an officer must have reasonable suspicion that the driver is under the influence. This suspicion may arise from observations such as erratic driving behavior, slurred speech, or the smell of alcohol. Failure to establish reasonable suspicion before administering FSTs can lead to the test results being deemed inadmissible in court.

How Virginia courts use Field Sobriety Tests

In Virginia, the results of FSTs can be used as evidence to support a DUI charge. However, it's important to understand how the courts evaluate this evidence.

Standardized vs. Non-Standardized Tests

As mentioned earlier, the NHTSA has approved three standardized FSTs: the HGN, WAT, and OLS tests. These tests are considered more reliable because they have standardized instructions and scoring criteria. Non-standardized tests, such as the finger-to-nose or alphabet recitation test, are less reliable and may not be given as much weight in court.

Weight of Field Sobriety Test Evidence

While FST results can be used as evidence of impairment, they are not considered conclusive proof. Judges and juries must evaluate the reliability and accuracy of the tests, taking into account factors such as the officer's qualifications, the driver's medical conditions, and the circumstances surrounding the tests. FST evidence is often combined with other evidence, such as blood alcohol content (BAC) tests, to establish a case for DUI.

Challenges to Field Sobriety Tests

A skilled Fairfax DUI lawyer, like Mr. Bezilla, can challenge the validity of FSTs on various grounds, potentially weakening the prosecution's case. If you are facing a DUI charge, call today for a free consultation.

Potential Errors in Test Administration

If the officer did not follow proper procedures when administering the FSTs, their results may be deemed unreliable. An experienced attorney can scrutinize the officer's actions and identify any deviations from the standard protocol.

Medical and Environmental Factors

Certain medical conditions, such as inner ear problems, neurological disorders, or injuries, can affect a person's performance on FSTs. Additionally, environmental factors, such as uneven surfaces or poor lighting, can also impact test results. A knowledgeable DUI lawyer can present evidence of these factors to challenge the validity of the FSTs.


Field Sobriety Tests play a significant role in Virginia DUI cases, but their results are not infallible. A competent Fairfax DUI lawyer can assess the circumstances surrounding the tests and challenge their validity, potentially leading to a better outcome for the accused. If you find yourself facing a DUI charge, it's essential to consult with an experienced attorney who understands the intricacies of FSTs and how Virginia courts use them.


  1. What are the three standardized Field Sobriety Tests? The three standardized FSTs are the Horizontal Gaze Nystagmus Test, Walk-and-Turn Test, and One-Leg Stand Test.
  2. Can a driver refuse to take Field Sobriety Tests in Virginia? Yes, a driver can refuse to take FSTs in Virginia.
  3. Are Field Sobriety Tests accurate indicators of intoxication? While FSTs can be reliable indicators of impairment when properly administered, they are not foolproof. Many factors can affect the results, including medical conditions, environmental factors, and errors in test administration.
  4. What happens if an officer did not follow proper procedures when administering Field Sobriety Tests?If an officer did not follow proper procedures when administering FSTs, a skilled DUI lawyer may be able to argue that the results are unreliable and should not be admissible in court.
  5. How do Virginia courts weigh Field Sobriety Test evidence in DUI cases? Virginia courts consider FST evidence as part of the overall case against a driver accused of DUI. The weight given to FST results depends on factors such as the officer's qualifications, the driver's medical conditions, and the circumstances surrounding the tests. FST evidence is often combined with other evidence, like blood alcohol content tests, to establish a case for DUI.

Contact Me Today

Mr. Bezilla is committed to answering your questions about Traffic Offenses, DUI, Criminal Misdemeanors, Domestic Abuse, Sex Offenses, Drug Offenses, Robbery, Burglary, Murder, Theft Crimes, White Collar Crimes, and Civil Matters in Virginia.

I offer a Free Consultation and I'll gladly discuss your case with you at your convenience. Contact me today to schedule an appointment.