By: Parsons, Graham & Day, LLC June 15, 2025

The Role of Field Sobriety Tests in Tulsa DUI Cases

What Are Field Sobriety Tests?

Police officers utilize field sobriety tests to determine if a driver has impaired motor skills, which can be an indicator of intoxication. Even so, these tests are not always accurate and can be difficult to perform under normal conditions. Factors like weather, road conditions, and a person’s physical health can affect their performance.

In Oklahoma, law enforcement uses a standardized set of three tests developed by the National Highway Traffic Safety Administration (NHTSA). These are the only FSTs that are considered scientifically reliable in court.

The Horizontal Gaze Nystagmus (HGN) Test: The officer checks for involuntary eye jerking by having you follow a stimulus with your eyes, without moving your head. The officer is looking for signs of impairment in how your eyes track the object
The Walk-and-Turn Test: For this test, you must walk heel-to-toe in a straight line for a certain number of steps, turn, and walk back. An officer is looking for signs like stepping off the line, losing your balance, or starting too soon
The One-Leg Stand Test: The officer instructs you to raise one leg about six inches off the ground and hold that position. This test is designed to assess your balance and ability to follow instructions simultaneously.

Can I Refuse a Field Sobriety Test in Oklahoma?

In Oklahoma, you have the right to refuse a field sobriety test. These tests are voluntary and are not the same as a chemical test (like a breathalyzer or blood test). An officer cannot punish you with an immediate driver’s license suspension just for refusing an FST.

It’s a different story with a chemical test. Under Oklahoma’s implied consent law (Oklahoma Statutes, Title 47, Section 751), any person driving on a public road is considered to have consented to a blood or breath test if an officer has probable cause to believe they are under the influence. Unlike refusing to perform FSTs, refusing a chemical test can lead to an automatic driver’s license suspension.

How Field Sobriety Tests Are Used in a DUI Case

The results of field sobriety tests can be used as evidence against you in court. The officer will testify about their observations and your performance on the tests. Even if you pass the tests, the officer’s subjective observations about your behavior can still be used as evidence. For example, they might testify that you had slurred speech, smelled of alcohol, or were fumbling for your license and registration.

How Tests are Used in Court

The officer’s testimony provides the prosecution with a narrative of your alleged impairment from the moment you were stopped. The prosecutor will use this testimony to establish that you were exhibiting physical and mental signs of being under the influence, which strengthens the case against you.

A skilled defense attorney will often challenge the validity of these tests by arguing that they were not administered correctly, the driver had a physical condition that affected their performance, or the environmental conditions (like poor lighting or uneven pavement) made the tests impossible to perform accurately.

DUI and Car Insurance in Oklahoma

After an arrest, you might also have concerns about your car insurance. It is essential to know that Oklahoma does not have Personal Injury Protection (PIP). Instead, Oklahoma is a “fault” state, which means the at-fault driver’s insurance is responsible for paying for damages.

Determining fault in a motor vehicle accident is a key difference from “no-fault” states, where your own insurance would cover your initial medical bills. In Oklahoma, to be compensated for injuries after a car accident, you must pursue a claim against the at-fault driver’s insurance company. Even so, a DUI charge can complicate this process and affect your insurance rates and policy.

Why You Need a Lawyer for Your DUI Case

The complexity of field sobriety tests and Oklahoma’s DUI laws makes having a skilled defense attorney essential. A qualified lawyer can challenge the results of an FST by arguing that the test was improperly administered or that external factors affected your performance.

For example, a skilled DUI defense lawyer can question the officer’s initial reason for stopping you in the first place. If the officer did not have probable cause to stop you, a defense lawyer can argue that any evidence should be thrown out, significantly weakening the state’s case.

A lawyer can also help you understand your options and whether you should challenge the chemical test results. Our team is knowledgeable about Oklahoma laws and can provide you with skilled legal advice to ensure you make informed decisions.

At Parsons, Graham & Day, LLC, we have extensive experience representing individuals in criminal cases, from traffic matters to more serious charges. We understand how intimidating it can be for someone facing criminal charges. We work diligently to ensure clients receive personal attention from our staff throughout their case. Our attorneys are committed to helping you navigate this challenging time so that you can move forward with your life.