How Field Sobriety Tests Are Challenged In Court
Field sobriety tests are a common part of DUI investigations, but they don’t always provide a clear picture of whether someone was impaired. An officer’s instructions, the testing conditions, and the way the results are interpreted can all affect their reliability. In some cases, those issues provide grounds to challenge the evidence in court.
If you’ve been charged with DUI in Columbia or elsewhere in South Carolina, The Law Office of Jonathan M. Harvey provides experienced criminal defense representation. In this article, we explain how field sobriety test evidence may be challenged in court and what that could mean for your DUI case.
What Are Field Sobriety Tests?
Field sobriety tests are roadside exercises that police officers use to help determine whether a driver is impaired. In South Carolina, officers most commonly use the three standardized tests developed by the National Highway Traffic Safety Administration (NHTSA):
- Horizontal Gaze Nystagmus (HGN): The driver is asked to follow a small object, such as a pen or a finger, with their eyes only.
- Walk-and-Turn: The driver walks nine heel-to-toe steps in a straight line, turns, and walks back in the same manner.
- One-Leg Stand: The driver stands on one foot for about 30 seconds while counting out loud.
Although these tests are widely used, their purpose is to determine whether impairment affects a driver’s coordination or ability to perform divided-attention tasks. They don’t measure blood alcohol concentration or conclusively prove that someone was under the influence. Instead, officers consider the results alongside other evidence when deciding whether to make a DUI arrest, and the results can be challenged in court.
How Can Field Sobriety Tests Be Challenged?
Field sobriety tests aren’t conclusive, and their results can be challenged in court. A defense attorney will closely examine how the tests were conducted and whether the evidence supports the officer’s conclusions.
Some of the most common challenges include:
- Improper testing procedures: Standardized field sobriety tests are intended to be administered a certain way. If the officer failed to follow those procedures, the reliability of the results may be questioned.
- Conditions unrelated to impairment: Uneven pavement, poor weather, injuries, certain medical conditions, medications, and even nervousness can affect a driver’s performance during the tests.
- Video evidence: Dash camera or body camera footage may provide additional context about how the tests were administered and how the driver performed during the investigation.
Speak With a Columbia DUI Defense Attorney
Field sobriety tests can be challenged when the facts and evidence support doing so. An experienced defense attorney can evaluate how the tests were administered, review the prosecution’s evidence, and determine the strongest path forward.
If you’ve been charged with DUI in Columbia or anywhere in South Carolina, contact The Law Office of Jonathan M. Harvey. Jonathan M. Harvey has represented clients in South Carolina criminal courts for decades and is prepared to discuss your case and legal options. Call 803-779-3363 or submit a contact form to get started.