Field Sobriety Tests: How Reliable Are They?

As a DUI defense attorney in Illinois, I understand that field sobriety tests (FSTs) play a crucial role in DUI investigations. Law enforcement officers use these tests to assess a driver’s level of impairment. However, the reliability of FSTs is often questioned, and their results can be challenged in court. I will now explain the types of field sobriety tests, their reliability, and common challenges in court.

Types of Field Sobriety Tests

Field sobriety tests are standardized procedures used by police officers to determine whether a driver is impaired. The three most common tests are the Horizontal Gaze Nystagmus (HGN), the Walk-and-Turn, and the One-Leg Stand.

Horizontal Gaze Nystagmus (HGN): The HGN test involves the officer asking the driver to follow a moving object, such as a pen, with their eyes. The officer looks for involuntary jerking of the eyes, which can indicate impairment. However, factors such as fatigue, medications, and certain medical conditions can affect eye movement and produce false positives.

Walk-and-Turn: This test requires the driver to take nine steps heel-to-toe along a straight line, turn on one foot, and return in the same manner. The officer looks for signs of imbalance, such as stepping off the line, using arms for balance, or taking the incorrect number of steps. However, physical conditions, footwear, and environmental factors can influence performance.

One-Leg Stand: The driver must stand on one leg while counting aloud for 30 seconds. The officer notes any swaying, using arms for balance, hopping, or putting the foot down. Similar to the Walk-and-Turn test, physical impairments, and environmental conditions can impact the results.

Reliability of Field Sobriety Tests

The National Highway Traffic Safety Administration (NHTSA) has standardized FSTs to improve their reliability. However, several factors can still affect their accuracy:

Subjectivity: FSTs rely heavily on the officer’s judgment, which can introduce bias and variability. Different officers may interpret the same behaviors differently, leading to inconsistent results.

Environmental Factors: Conditions such as uneven pavement, poor lighting, and adverse weather can affect a driver’s performance on FSTs, leading to false indications of impairment.

Physical and Medical Conditions: Conditions such as injuries, disabilities, and certain medical conditions can affect a driver’s ability to perform FSTs, resulting in inaccurate assessments.

Nervousness and Anxiety: Being pulled over and subjected to FSTs can cause anxiety and nervousness, which can negatively impact a driver’s performance, even if they are not impaired.

Challenging Field Sobriety Test Results in Court

Given the potential for inaccuracies, challenging the results of FSTs is a common defense strategy in DUI cases. Here are some ways to dispute FST evidence:

Questioning Officer Training and Procedures: Attorneys can examine whether the officer administering the FSTs followed proper protocols and whether they were adequately trained. Any deviation from standardized procedures can cast doubt on the reliability of the results.

Highlighting Environmental Conditions: By documenting the conditions under which the FSTs were conducted, such as poor lighting or uneven surfaces, attorneys can argue that these factors contributed to the driver’s poor performance.

Presenting Alternative Explanations: Medical records and expert testimony can be used to show that physical impairments or medical conditions affected the driver’s ability to perform the FSTs, rather than impairment due to alcohol or drugs.

Cross-Examining the Officer: Cross-examining the arresting officer can reveal inconsistencies or biases in their observations and assessments. Effective questioning can undermine the credibility of the FST results.

Choose the Law Offices of David L. Freidberg to Defend Your Case!

Why Choose Us? At The Law Offices of David L. Freidberg, we have decades of experience defending clients against DUI charges. We understand the complexities of field sobriety tests and know how to challenge their reliability in court. Contact us for your free case review and consultation.

Contact us today for a free consultation 24/7: 📞 (312) 560-7100 📞 Toll-free at (800) 803-1442.

We proudly serve clients throughout Chicago and the surrounding areas. Let us help you fight for your future. Read the full article on our website for more detailed information.