What Makes Field Sobriety Tests Contestable?

Field Sobriety Tests (FSTs) are commonly used by law enforcement officers in Maryland to determine whether a driver is under the influence of alcohol or drugs.

However, these tests aren’t foolproof, and there are several reasons why their validity can be challenged in court. 

From issues with administration and subjective interpretation to environmental factors and medical conditions, there are multiple grounds for contesting FST results.

Given these concerns, it’s no surprise that FSTs are frequently challenged in court. A skilled Maryland DUI defense lawyer can argue that the tests were improperly administered, that external factors played a role in poor performance, or that the officer’s judgment was flawed. 

By casting doubt on the reliability of FST results, our law firm at Marvel & Emche, P.A. can help weaken the prosecution’s case and increase the chance of a fair outcome for the accused. As DUI defense lawyers in Salisbury, Maryland, we're ready to help you with your case.

What Are Field Sobriety Tests?

FSTs are a set of physical and cognitive exercises that officers administer during a traffic stop when they suspect a driver is impaired. The three standardized tests recognized by the National Highway Traffic Safety Administration (NHTSA) are:

• Horizontal Gaze Nystagmus (HGN) Test: The officer observes the driver’s eye movements as they follow an object (usually a pen or flashlight) from side to side. Involuntary jerking of the eyes is considered a sign of impairment. However, factors like medical conditions or fatigue can sometimes cause similar eye movements, making the test less reliable.

• Walk-and-Turn (WAT) Test: The driver must take nine heel-to-toe steps in a straight line, turn on one foot, and return in the same manner. Officers look for signs of imbalance, inability to follow instructions, and stepping off the line. External factors, like uneven ground or footwear, can also impact a person's ability to perform this test accurately.

• One-Leg Stand (OLS) Test: The driver is asked to stand on one leg for about 30 seconds while keeping their arms at their sides. The officer notes swaying, hopping, or using arms for balance. Conditions like leg injuries or nervousness can lead to false signs of impairment during this test.

While these tests are meant to assess impairment, they’re highly contestable for a variety of reasons.

Reasons Field Sobriety Tests Are Contestable in Maryland

One of the primary concerns with FSTs is their reliance on human judgment rather than objective scientific measurements. Officers are trained to look for signs of impairment, but their evaluations are often influenced by personal biases, preconceptions, and external factors that may have nothing to do with intoxication. 

Another concern with FSTs is that they’re administered in uncontrolled environments. Unlike a laboratory test, where variables are controlled to make sure of accuracy, FSTs are often performed on the side of the road, where factors such as poor lighting, uneven surfaces, or bad weather can significantly impact performance. 

Moreover, a driver’s physical condition, age, or even the type of shoes they’re wearing can make passing the test difficult, regardless of their sobriety.

Other factors that can make an FST contestable include the following:

Subjectivity of Officer Interpretation

FST results rely heavily on an officer’s judgment. Unlike breathalyzers or blood tests, which provide measurable data, these tests depend on how an officer perceives a driver’s actions. Bias, preconceptions, or lack of training can lead to inaccurate assessments.

Improper Administration

Law enforcement officers must follow strict protocols when administering FSTs. If an officer deviates from the standardized procedures outlined by the NHTSA, the results may be unreliable. For example:

• Failing to give clear instructions

• Administering the test on uneven or slippery ground

• Rushing through the test

• Using non-standardized tests

Improper administration of field sobriety tests can significantly impact their accuracy and effectiveness, which is why it’s important to challenge any deviations from the proper procedures in court.

Medical and Physical Conditions

Certain medical conditions, injuries, or disabilities can affect a person’s ability to perform FSTs, even if they’re sober. Conditions like vertigo, neurological disorders, arthritis, or past surgeries can make it difficult to balance or walk in a straight line. Additionally, older individuals or those with weight-related issues may struggle with physical tasks.

Environmental Factors

The location where an FST is conducted can impact a driver’s performance. Uneven pavement, poor lighting, bad weather, or nearby traffic can all affect a person’s ability to focus or balance. Additionally, wearing high heels or restrictive clothing may make some movements harder to execute.

Nervousness and Stress

Being pulled over by the police is a stressful experience, even for sober drivers. Anxiety, fear, and adrenaline can cause someone to shake, stumble, or misunderstand instructions, leading to an officer interpreting these as signs of impairment.

Lack of Correlation With Actual Impairment

Studies have shown that FSTs aren't always reliable indicators of impairment. Even under ideal conditions, sober individuals can fail these tests as well. Since alcohol and drug levels affect people differently, someone might appear uncoordinated without actually being legally impaired.

How a DUI Defense Lawyer Can Challenge FSTs

A skilled DUI defense lawyer can challenge FST results in various ways to weaken the prosecution’s case. Here’s how they can help.

Reviewing Body Camera and Dashcam Footage

Many police officers wear body cameras or have dashcams that record traffic stops. A lawyer can analyze this footage to identify errors in how the test was administered, officer bias, or environmental factors that affected performance.

Examining Police Reports for Inconsistencies

A criminal defense lawyer can review the arresting officer’s report for inconsistencies or vague statements. If the officer’s description of the test doesn’t match the video evidence or seems exaggerated, it can cast doubt on the FST results.

Questioning Officer Training and Experience

Not all officers receive the same level of training on FSTs. A defense lawyer can investigate whether the officer was properly trained and if they have a history of administering these tests incorrectly. If there’s evidence of incompetence or procedural errors, the results may be deemed unreliable.

Bringing in Expert Witnesses

Expert witnesses, such as forensic toxicologists or medical professionals, can testify about the scientific flaws of FSTs and how medical conditions or external factors could have influenced the results.

Highlighting Alternative Explanations for Performance Issues

A criminal defense lawyer can argue that poor performance was due to fatigue, nerves, physical ailments, or external conditions rather than intoxication. This can help create reasonable doubt about the prosecution’s claims.

Challenging the Stop’s Legality

If the traffic stop was unlawful (e.g., no probable cause for the stop), any evidence obtained, including FST results, may be inadmissible in court. A defense lawyer can file motions to suppress evidence if the stop violated constitutional rights.

Negotiating Plea Deals or Case Dismissals

If a lawyer can cast enough doubt on the validity of the FSTs, they may be able to negotiate reduced charges, alternative sentencing, or even case dismissal.

Contact a DUI Defense Lawyer Today

Our skilled DUI defense lawyers can challenge the validity of Field Sobriety Test results by examining police procedures, cross-examining officers, presenting expert witness testimony, and questioning the legality of the stop. We serve clients in Salisbury, Northwood, White Plains, West Wood, Princess Anne, Cambridge, and Ocean City. Contact our firm at Marvel & Emche, P.A. today to learn more.