Field sobriety tests (FSTs) are used by law enforcement to help gauge if a driver is under the influence of alcohol or drugs. In Southern California, as in other parts of the United States, these tests can significantly impact the outcome of a DUI arrest. Contesting the validity and accuracy of FSTs can be crucial in defending against DUI charges.

Understanding Field Sobriety Tests

Types of Field Sobriety Tests

Field sobriety tests are intended to assess a person’s physical and cognitive abilities to determine impairment. The most common standardized tests include the Horizontal Gaze Nystagmus (HGN) test, the Walk-and-Turn test, and the One-Leg Stand test. Each of these tests has specific guidelines and procedures that officers must follow to ensure accuracy.

The Horizontal Gaze Nystagmus Test

The HGN test involves an officer observing the eyes of a suspect as they follow a moving object, such as a pen or flashlight. The officer looks for involuntary jerking of the eyes, which can indicate intoxication. This test is considered highly reliable, but it requires precise administration and interpretation.

The Walk-and-Turn Test

The Walk-and-Turn test requires a suspect to take nine steps along a straight line, turn on one foot, and return in the same manner, walking toe-to-heel the whole time. The officer looks for balance issues, starting too soon, incorrect number of steps, and failure to follow instructions.

The One-Leg Stand Test

In the One-Leg Stand test, the suspect must stand on one leg while counting aloud for 30 seconds. The officer observes for swaying, using arms for balance, hopping, or putting the foot down.

Common Challenges to Field Sobriety Tests

Questioning the Officer’s Training and Experience

One strategy for contesting FSTs is to challenge the officer’s training and experience. Law enforcement officers must undergo specific training to administer these tests properly. If an officer lacks proper certification or has a history of improperly conducting tests, their credibility can be questioned.

Environmental Conditions

The environment in which the tests are conducted can significantly impact the results. Poor lighting, uneven surfaces, inclement weather, and traffic distractions can all affect a suspect’s performance. Highlighting these conditions can cast doubt on the reliability of the test results.

Medical Conditions and Physical Limitations

Medical conditions, injuries, or physical limitations can impair a person’s ability to perform FSTs accurately. Conditions such as inner ear problems, neurological disorders, or even fatigue can lead to poor performance. Presenting medical records or expert testimony can help explain why a suspect may have failed the tests.

Nervousness and Anxiety

Being stopped by the police and asked to perform field sobriety tests can cause significant stress and anxiety, which can affect performance. Arguing that nervousness rather than intoxication led to poor performance can be a valid defense.

Legal Defenses Against Field Sobriety Tests

Challenging the Legality of the Stop

One of the most effective defenses is to challenge the legality of the traffic stop itself. If the officer did not have reasonable suspicion to stop the vehicle, any evidence obtained, including FST results, may be inadmissible in court, which can lead to the dismissal of DUI charges.

Improper Administration of Tests

Officers must follow strict guidelines when administering field sobriety tests. Any deviation from these procedures can call the results into question. Cross-examining the officer about the exact steps they took and comparing them to standardized protocols can uncover inconsistencies.

Lack of Probable Cause for Arrest

After conducting FSTs, an officer must have probable cause to arrest for DUI. If the results of the tests are inconclusive or if the officer’s observations do not provide sufficient evidence of impairment, the arrest may be challenged.

Expert Testimony

Expert testimony can be a powerful tool in contesting field sobriety tests. Experts in fields such as pharmacology, neurology, or toxicology can provide insights into factors that could affect test performance. Their testimony can help undermine the prosecution’s case by offering alternative explanations for the suspect’s behavior besides intoxication.

Practical Tips for Contesting Field Sobriety Tests

Documenting the Scene

If you are pulled over and asked to perform field sobriety tests, try to document the scene as much as possible. Take note of the lighting, weather conditions, and the surface where the tests are conducted. If possible, record the interaction on your phone or with a dashcam. This evidence can be crucial in challenging the validity of the tests later.

Requesting an Independent Test

If you believe the FST results are inaccurate, you can request an independent blood or breath test. This test can provide an additional piece of evidence that may support your defense. Be aware that the timing of the test is important, as alcohol levels in the blood can change over time.

Hiring an Experienced DUI Attorney

Navigating the complexities of DUI law requires expertise. Hiring an experienced DUI attorney who understands the intricacies of field sobriety tests and local laws in Southern California can greatly enhance your defense. An attorney can help identify weaknesses in the prosecution’s case, gather evidence, and present a compelling argument in court.

Seek Legal Guidance

Field sobriety tests are a critical component of DUI arrests, but they are not infallible. There are numerous strategies for contesting the results of these tests, ranging from questioning the officer’s training to highlighting environmental conditions and medical issues. By working with an experienced DUI attorney, individuals facing DUI charges in Southern California can mount a robust defense and increase their chances of a favorable outcome.

Are you facing a DUI charge? The Socal Law Network is here to help—call 949-779-3799 to schedule a free consultation today.