How a Defense Attorney Challenges Field Sobriety Test Results

In reality, field sobriety tests (FSTs) are highly subjective, often administered incorrectly, and don’t always reflect whether someone is legally impaired. That’s why an experienced defense attorney will carefully examine how these tests were conducted and whether the results can truly be trusted in court.

What Are Field Sobriety Tests?

Police in Pennsylvania commonly use three standardized field sobriety tests developed by the National Highway Traffic Safety Administration (NHTSA):

1. Horizontal Gaze Nystagmus (HGN): The officer asks you to follow an object (like a pen) with your eyes. They watch for jerky movements, which may indicate impairment.

2. Walk-and-Turn: You must take 9 heel-to-toe steps in a straight line, turn, and take 9 steps back.

3. One-Leg Stand: You’re asked to stand on one foot for 30 seconds without swaying, hopping, or using your arms for balance.

These tests are meant to help officers decide whether they have probable cause for a DUI arrest.

Why These Tests Aren’t Always Reliable

Field sobriety tests are not scientific proof of intoxication. Many factors can affect your ability to perform them, including:

• Fatigue

• Nervousness or anxiety

• Uneven or slippery surfaces

• Poor lighting or bad weather

• Medical conditions (like vertigo or arthritis)

• Wearing dress shoes or heels

• Age or physical disabilities

Even sober people often fail these tests.

How Police Mistakes Can Affect Your Case

Officers are required to follow very specific protocols when administering these tests. If they don’t, the results can be challenged. Common mistakes include:

• Not giving clear instructions

• Rushing the suspect or interrupting the test

• Misinterpreting body movements

• Using non-standardized or made-up tests

• Performing the test in bad conditions (on gravel, in traffic, etc.)

Any of these errors can result in false positives—and wrongful arrests.

How a Defense Attorney Challenges FSTs in Court

A skilled DUI attorney will look at every detail surrounding your field sobriety test to raise doubt about its reliability. Common strategies include:

✅ Cross-examining the officer’s testimony to uncover inconsistencies or bias
✅ Reviewing dashcam or bodycam footage to show the test conditions were poor
✅ Arguing that you have a medical condition that affects balance or coordination
✅ Challenging the officer’s training and certification in administering FSTs
✅ Filing motions to suppress the test results if your rights were violated

By showing that the tests were flawed, your lawyer can weaken the prosecution’s case—sometimes enough to have charges reduced or dismissed.

Are You Required to Take Field Sobriety Tests in PA?

No. In Pennsylvania, you are not legally required to perform field sobriety tests. You can politely decline.

However, if you refuse a chemical test (like a breathalyzer or blood test) after arrest, you may face civil penalties under Pennsylvania’s implied consent law—such as license suspension.

Still, saying no to FSTs can limit the evidence police gather against you.

What If You’ve Already Taken the Tests and Were Arrested?

Don’t panic. Many DUI cases still have weaknesses, even if you took and failed field sobriety tests. These tests are just one piece of the puzzle—and often the easiest to challenge with the right legal strategy.

📞 Contact Mark D. Hauser, Criminal Defense Attorney, Today

Field sobriety tests are not infallible—and they shouldn't decide your future. If you’ve been arrested for DUI in Pennsylvania, let an experienced defense lawyer fight for you. With over 30 years of experience in DUI and criminal defense, Mark D. Hauser has successfully challenged FSTs and helped clients avoid the harsh consequences of a DUI conviction.

📞 Contact Mark D. Hauser, criminal defense attorney, today for a confidential case evaluation.