02|2025

Facing a DUI charge can be a stressful and overwhelming experience, especially if your arrest was based on field sobriety test results. Many people do not realize that these tests are not always reliable, and several external factors can lead to false or misleading results. In fact, law enforcement officers often rely on field sobriety tests (FSTs) as one of their primary tools to determine intoxication, even though scientific studies have shown that these tests are far from foolproof.

If you have been arrested for DUI in Phoenix based on a field sobriety test, you need to understand your legal rights and possible defense strategies. A skilled field sobriety test attorney can challenge the validity of the test, identify potential flaws in the officer’s administration, and present strong arguments in court to defend you against unfair DUI charges.

Understanding Field Sobriety Tests and Their Purpose

Field sobriety tests are a series of physical and cognitive exercises that police officers use to assess whether a driver is impaired by alcohol or drugs. These tests are commonly administered during traffic stops when an officer suspects a driver of being under the influence.

The three standardized field sobriety tests, as approved by the National Highway Traffic Safety Administration (NHTSA), include:

  • Horizontal Gaze Nystagmus (HGN) Test – This test examines the involuntary jerking of the eyes when they move from side to side. Officers believe that exaggerated jerking is an indicator of intoxication.
  • Walk-and-Turn Test – The driver must take nine heel-to-toe steps in a straight line, turn on one foot, and return in the same manner. Officers assess balance, coordination, and the ability to follow instructions.
  • One-Leg Stand Test – The driver must stand on one leg while counting out loud for 30 seconds. Officers look for signs of impairment, such as swaying, hopping, or using arms for balance.

These tests are intended to measure impairment, but they are not scientifically conclusive. Even when administered correctly, field sobriety tests can yield false results due to various external and individual factors.

Common Problems with Field Sobriety Tests

While police officers use FSTs as a key tool in DUI investigations, they are far from perfect. Many factors can lead to a sober person failing these tests, which can result in an unjust DUI arrest.

1. Officer Errors and Subjectivity

One of the most significant issues with field sobriety tests is that they are subjective. Unlike a breathalyzer or blood test, which provides numerical results, FSTs rely entirely on an officer’s interpretation. The problem is that officers may already suspect a driver is impaired before administering the test, leading to biased evaluations.

Additionally, officers may make mistakes when conducting the tests, such as:

  • Giving unclear or incomplete instructions
  • Not considering environmental factors that could affect performance
  • Rushing the test or not giving the driver a fair chance to comply
  • Misinterpreting normal behavior as signs of impairment

If an officer makes errors while administering a field sobriety test, an attorney can argue that the test results should not be used as evidence in court.

2. Environmental and Road Conditions

Field sobriety tests are often conducted on the side of the road, which is not an ideal environment for assessing a person’s balance and coordination. Several external conditions can impact test performance, including:

  • Uneven or sloped surfaces
  • Poor lighting or bad weather conditions
  • High-traffic areas with loud noise and distractions
  • Windy or cold weather that affects a person’s stability

A skilled attorney can argue that the test was conducted in conditions that unfairly impacted your ability to perform well, making the results unreliable.

3. Medical and Physical Conditions

Certain medical conditions, disabilities, or even normal physical traits can affect a person’s ability to complete field sobriety tests, regardless of whether they have consumed alcohol. Some conditions that can impact test performance include:

  • Inner ear problems that affect balance
  • Neurological disorders
  • Previous injuries to the legs, knees, or back
  • Anxiety or nervousness during the test
  • Age-related issues, especially for older drivers

Even wearing improper footwear, such as high heels or sandals, can make it difficult to perform well on these tests. If you have a medical condition or physical limitation that affected your test performance, an attorney can use this as a defense in your DUI case.

4. Nervousness and Stress

Being pulled over by the police is a stressful experience for most drivers. The pressure of being watched and judged while performing a physical task can cause anyone to make mistakes. Anxiety and nervousness can lead to poor performance on field sobriety tests, even if the driver is completely sober.

A DUI defense lawyer can argue that nervousness and stress, rather than intoxication, were the reasons for a poor test performance.

How a DUI Attorney Can Challenge Field Sobriety Test Evidence

If you were arrested for DUI based on field sobriety test results, an experienced attorney can challenge the validity of the evidence in multiple ways. Some of the most common legal strategies include:

1. Questioning the Officer’s Training and Experience

Officers must receive specialized training to properly administer field sobriety tests. If an officer lacked the necessary training or failed to follow proper procedures, your lawyer can challenge the reliability of the test results.

Your attorney may request body camera footage or police reports to review the officer’s conduct during the test. If there are discrepancies, this can be used to weaken the prosecution’s case.

2. Challenging the Accuracy of the Test Conditions

If the test was conducted in an area with uneven pavement, poor lighting, or distractions, your lawyer can argue that external factors led to an unfair assessment. Environmental conditions can significantly impact test performance, and these factors should be taken into account in your defense.

3. Using Medical Evidence to Explain Poor Performance

If you have a medical condition or physical limitation that affected your ability to perform field sobriety tests, your attorney can present medical records and expert testimony to prove that your poor test performance was due to health-related issues, not intoxication.

4. Introducing Video Evidence

Many DUI arrests are recorded on police body cameras or dash cameras. Your attorney can review the footage to see if the officer properly conducted the test. If the video contradicts the officer’s report or shows unfair testing conditions, it can be used to challenge the DUI charge.

5. Arguing That the Test Was Unreliable

Since field sobriety tests are not scientifically proven to be 100% accurate, your lawyer can challenge their reliability in court. Studies have shown that even when conducted correctly, these tests have a margin of error. Your attorney can use expert testimony to highlight the flaws and inaccuracies associated with field sobriety testing.

The Importance of Hiring a Field Sobriety Test Attorney in Phoenix

Fighting a DUI charge based on field sobriety test results requires in-depth legal knowledge and experience. If you attempt to handle your case alone, you may face severe penalties, including fines, license suspension, and even jail time. A skilled DUI attorney can review every aspect of your arrest, identify weaknesses in the prosecution’s case, and present strong legal arguments to challenge the charges against you.

By working with a knowledgeable field sobriety test attorney in Phoenix, you increase your chances of having the charges reduced or dismissed. Do not let an unreliable test determine your future—get the legal representation you deserve and protect your rights.

If you have been arrested for DUI in Phoenix and believe your field sobriety test was unfair, contact a DUI defense lawyer today to discuss your case and explore your legal options.

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