Standardized Field Sobriety Tests (SFSTs) were developed as a means to assess impairment in drivers suspected of driving under the influence (DUI). These tests have been widely adopted by law enforcement agencies across the United States, thanks to the guidelines established by the National Highway Traffic Safety Administration (NHTSA).
How SFSTs Were Developed
The development of SFSTs was based on scientific research and empirical studies. The NHTSA conducted extensive research to determine which tests would provide the most reliable indicators of impairment. Through this research, they identified three tests that have become the standard for assessing impairment in DUI cases:
The Horizontal Gaze Test (HGN)
The Horizontal Gaze Test (HGN) is a commonly used field sobriety test that helps determine if a driver is under the influence of alcohol. It does this by measuring their eye movements.
These indicators are believed to be more pronounced in people who have consumed alcohol.
It's important to note that the HGN test has its limitations and can be challenged in court. Some common challenges include:
If you're facing DUI charges and have undergone an HGN test, it's crucial to understand how this test works and its potential weaknesses. Consulting with an experienced criminal defense attorney can provide you with valuable insights, help identify any flaws in HGN evidence, and develop effective strategies for challenging its reliability in court.
2. The Walk-and-Turn Test
The Walk-and-Turn Test is a standardized field sobriety test used by law enforcement to assess a driver's level of impairment. This test helps determine if a person is under the influence of alcohol or drugs by evaluating their divided attention and physical coordination.
During the Walk-and-Turn Test, the driver needs to perform the following steps:
The police officer will closely observe how well you follow these instructions while maintaining balance and coordination.
Procedural Errors That Can Invalidate the Accuracy of the Walk-and-Turn Test
Several factors can affect the accuracy of the Walk-and-Turn Test:
These factors can lead to potential misinterpretation of the results by law enforcement, making it important to understand how they may impact your case.
Challenging the accuracy of the Walk-and-Turn Test requires a thorough understanding of its administration and potential sources of error. An experienced DUI defense attorney can analyze your specific situation and identify any procedural errors that may have compromised the validity of this field sobriety test.
3. The One-Leg Stand Test
The One-Leg Stand Test is another standardized field sobriety test (SFST) used by law enforcement to assess impairment in drivers suspected of driving under the influence (DUI). This test focuses on the individual's balance and stability, requiring them to stand on one leg while following specific instructions.
Understanding the balance and stability requirements of the One-Leg Stand Test
During the One-Leg Stand Test, the driver is instructed to raise one foot approximately six inches off the ground and maintain balance while counting out loud for a specified duration, typically 30 seconds. The individual is expected to keep their arms at their sides and maintain their balance without swaying, hopping, or putting their foot down.
This test aims to assess the driver's ability to divide attention between physical coordination and mental tasks. Impairment caused by alcohol or drugs can affect an individual's balance and stability, making it difficult for them to successfully complete this test.
Key defense strategies for challenging the One-Leg Stand Test results
There are several defense strategies that can be employed to challenge the validity of One-Leg Stand Test results:
Just like any other SFST, the One-Leg Stand Test must be administered correctly by law enforcement officers. Any procedural errors or deviations from the established guidelines can compromise the accuracy and reliability of the test results. For example, if the officer fails to provide clear instructions or does not properly demonstrate the test, it can lead to inaccurate interpretations of impairment.
Certain physical conditions or injuries can impact an individual's ability to perform the One-Leg Stand Test, even if they are not under the influence of alcohol or drugs. Conditions such as inner ear problems, leg injuries, or other medical issues may affect an individual's balance and stability, leading to false indicators of impairment during this test.
The conditions in which the One-Leg Stand Test is conducted can also affect the results. Uneven surfaces, poor lighting, inclement weather, or other external factors can make it more challenging for an individual to maintain their balance and stability during the test, potentially leading to inaccurate assessments of impairment.
By challenging the administration and interpretation of the One-Leg Stand Test, a skilled DUI defense attorney can raise doubts about the accuracy and reliability of the evidence presented against their client. This underscores the importance of consulting with a knowledgeable attorney who specializes in field sobriety testing issues to build a strong defense strategy.
Other Field Sobriety Tests Used by Law Enforcement
When it comes to assessing a driver's impairment during a DUI stop, law enforcement officers may use a variety of field sobriety tests to gather evidence. While standardized tests like the Horizontal Gaze Nystagmus (HGN), Walk-and-Turn, and One-Leg Stand are commonly recognized, there are other non-standardized tests that can still carry evidentiary weight in DUI cases. These additional tests include:
Navigating the legal complexities of DUI cases requires expert guidance. By consulting a skilled DUI defense attorney, you can ensure that your rights are protected and increase your chances of achieving a favorable outcome in court.
Contact Provenzano Law today, and let's start building your defense.