Field Sobriety Tests in Washington DUI Stops: What You Need to Know

In theory, under Washington State DUI laws. So, if a law enforcement officer asks you if you are willing to perform these tests, you are not legally required to comply. However, refusal to perform the tests can be used as evidence of guilty knowledge against you in court.

In other words, you are free to decline the test but it will be used against you in court as evidence of guilt, i.e., you thought you would fail. Knauss law generally advises our clients to decline “based on the advice of my attorney.”

This seemingly simple decision and phrase could be critical to your defense later.

At Knauss Law, our experienced DUI attorneys—many of whom are former prosecutors—have successfully challenged field sobriety tests in court. Here’s what you need to know about these tests, why they are problematic, and why you should think twice before agreeing to take one.

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What Are Field Sobriety Tests?

Field Sobriety Tests are physical and mental coordination tasks designed to assess impairment.

Before we describe the tests themselves it’s important to know this: the test starts before you know it – it begins while the officer is giving instructions. Officers typically have the subject stand heel to toe while they describe the tests. If you break that position it is supposedly a ‘clue’ and you are well on the way to failing before you start. If you doubt that at all, try standing heel to toe in your living room – it’s not easy to stay in the position even without the bright, strobing lights and the presence of someone who can arrest you carefully watching.

That said, FSTs include tests such as:

  • The One-Leg Stand: Balancing on one foot for 30 seconds.
  • The Walk and Turn: Walking heel-to-toe in a straight line, turning, and returning.
  • The Horizontal Gaze Nystagmus (HGN): Tracking eye movement for involuntary jerking while following a moving object (often a pen or flashlight).

These tests aim to provide officers with probable cause to make a DUI arrest, but their results are far from infallible.

Are Field Sobriety Tests Dependable?

The short answer: not entirely. While often presented as scientific, FSTs have a significant margin of error. Consider these facts:

  • National Highway Traffic Safety Administration (NHTSA) Data: Studies show the One-Leg Stand test has a failure rate of up to 35% for individuals with a blood alcohol concentration (BAC) at or below 0.08%. This means sober individuals may fail the test due to factors like fatigue, poor balance, or uneven ground.
  • Subjectivity: The interpretation of these tests relies heavily on the officer’s judgment. Stress, nerves, or even medical conditions can mimic signs of intoxication, leading to false positives.
  • Environmental Factors: Tests are often conducted on the side of the road, in poor lighting, and under stressful circumstances. Uneven pavement, weather conditions, or noise distractions can easily impact your performance.

Why You Should Decline to Perform Field Sobriety Tests

There are numerous reasons to decline an FST:

1. Pass/Fail Nature: Anything short of perfection can result in an arrest. Even a minor wobble during the One-Leg Stand may be interpreted as impairment.

2. No Legal Obligation: Unlike breath or blood tests, FSTs are not mandatory under Washington law.

3. Video Evidence Is Key: Most patrol vehicles are equipped, and many officers wear body cameras. Any misstep during the test will likely be recorded and used as evidence against you in court. Declining the test minimizes the risk of self-incrimination.

4. Medical and Physical Conditions: Age, injuries, or chronic conditions like arthritis or vertigo can cause someone to "fail" a test—even if they are entirely sober.

How Knauss Law Challenges Field Sobriety Tests

Our attorneys use a multi-faceted approach to challenge FST results in court:

  • Body Camera and Dashcam Footage: We carefully review video recordings to evaluate how the test was administered. Officers are required to follow specific protocols. Any deviation—like failing to provide clear instructions or conducting the test in unsafe conditions—can undermine the validity of the results.
  • Cross-Examination of the Arresting Officer: We question the officer’s training, experience, and observations. Did they document objective signs of impairment, or were they influenced by confirmation bias?
  • Expert Testimony: We bring in specialists to explain the unreliability of FSTs and highlight factors that could have affected your performance.
  • Medical Records: If you have a condition that could impact your balance or coordination, we present evidence to show how it might have influenced your test results.

What Should You Do During a DUI Stop?

If you’re pulled over under suspicion of DUI, follow these steps to protect your rights:

1. Remain Calm and Polite: Avoid sudden movements or confrontational behavior.

2. Provide Required Information: Hand over your driver’s license, registration, and proof of insurance when asked.

3. Invoke Your Rights: Politely decline to answer any questions beyond your basic identifying information. Say, “I would like to speak to my attorney.”

4. Decline Field Sobriety Tests: Say, “I respectfully decline to perform any voluntary field sobriety tests.”

5. Contact an Attorney Immediately: Call Knauss Law as soon as possible for guidance and representation.

The Knauss Difference: Your Defense Starts Here

At Knauss Law, we know how to dismantle the prosecution’s case, starting with the field sobriety test. Our team understands the tactics the state uses and how to counter them effectively. From challenging the legality of the stop to contesting flawed FST results, we leave no stone unturned in your defense.

Contact Us Today

If you’ve been accused of DUI in Washington State, don’t face the charges alone. Contact Knauss Law today for a consultation. Together, we’ll fight to protect your rights, challenge unreliable evidence, and secure the best possible outcome for your case.