Driving under the influence (DUI) or driving while ability impaired (DWAI) is a serious offense in Colorado, carrying consequences that can affect a person’s license, employment, and personal life. Law enforcement officers often rely on field sobriety tests (FSTs) as a tool to determine impairment during traffic stops.
While these tests are commonly used, they’re not infallible. In many cases, defendants have valid grounds to contest the results of FSTs, which can play a critical role in the defense of a DUI or DWAI charge.
At The Leier Law Office LLC, we understand that facing DUI or DWAI charges can be an overwhelming and stressful experience. Based in Fort Collins, Colorado, and serving communities including Loveland, Greeley, Windsor, and Evans, we approach every case with empathy and attention to detail.
Our attorney, an experienced former prosecutor, brings a unique perspective to defending clients, helping them understand their options and the legal process while advocating vigorously on their behalf. Our goal is to provide clear guidance and support during this challenging time, giving clients the confidence to address their charges thoughtfully and strategically.
Understanding why these tests may be challenged is an important step for anyone facing such charges. Keep reading or contact us today for more information.
What Are Field Sobriety Tests?
Field sobriety tests are a set of standardized exercises administered by police officers during traffic stops when they suspect a driver is impaired. The National Highway Traffic Safety Administration (NHTSA) developed three standardized tests:
Horizontal Gaze Nystagmus (HGN): Observes involuntary eye movements that may indicate impairment.
Walk-and-Turn (WAT): Requires the driver to take heel-to-toe steps along a straight line and turn in a specific manner.
One-Leg Stand (OLS): Involves standing on one leg while counting aloud to test balance and coordination.
Officers may also use additional, non-standardized tests or observations to evaluate a driver’s coordination, attention, and ability to follow instructions. While these tests can suggest impairment, their results are subjective and susceptible to error.
Why FSTs Can Be Inaccurate
Several factors can affect the reliability of field sobriety tests, making them potentially contestable in court. Some of the common issues include:
Medical conditions: Certain medical issues, such as inner ear disorders, neurological conditions, or injuries, can affect balance and coordination, leading to poor performance on FSTs.
Fatigue or stress: A tired or stressed driver may struggle with instructions, even if they’re not impaired.
Age and physical fitness: Older individuals or those with physical limitations may find tasks like the walk-and-turn challenging.
Environmental factors: Uneven surfaces, poor lighting, or inclement weather can interfere with test performance.
Because of these variables, failing a field sobriety test does not automatically prove impairment. In many cases, lawyers argue that the conditions surrounding the test contributed to a failed result.
Procedural Concerns with Field Sobriety Tests
Law enforcement officers must follow certain procedures when administering FSTs. Mistakes in these procedures can provide grounds for contesting test results. Some procedural concerns include:
Improper instructions: If the driver was not given clear, standardized instructions, their performance may not be an accurate reflection of impairment.
Timing errors: Failing to allow adequate time for the driver to complete the test can affect results.
Bias or preconception: Officers who have already determined a driver is impaired may inadvertently influence the outcome of the test.
Documentation errors: Inconsistent or incomplete notes about the test can weaken its credibility in court.
Challenging procedural errors is a common defense strategy in DUI and DWAI cases, highlighting that the results may not be reliable evidence of impairment.
Scientific Limitations of FSTs
Although field sobriety tests are widely accepted, they’re not foolproof indicators of alcohol or drug impairment. Studies have shown that:
False positives are possible: Some individuals who are sober can fail FSTs due to factors unrelated to alcohol or drugs.
Individual differences matter: Physical and cognitive differences between people can affect test outcomes, meaning two sober individuals may perform very differently.
Non-alcohol impairments: Fatigue, prescription medications, or anxiety can mimic signs of impairment observed during FSTs.
Understanding these limitations allows defense attorneys to argue that failing a field sobriety test doesn’t necessarily indicate DUI or DWAI.
The Human Factor in Field Sobriety Tests
One of the most overlooked aspects of field sobriety tests is the human element. Officers, like all humans, are subject to perception biases, fatigue, and judgment errors. Their observations may be influenced by personal expectations, prior experiences, or even subtle nonverbal cues from the driver.
For instance, if an officer expects someone to be impaired based on appearance or behavior before the test begins, it can unconsciously affect how they interpret the driver’s performance. This is often referred to as “confirmation bias” and is a well-documented factor in legal cases challenging FST results.
Additionally, drivers themselves may react differently to stress or anxiety during a traffic stop. Being pulled over can trigger a fight-or-flight response that impacts coordination, concentration, and speech. These natural physiological reactions can mimic signs of impairment, even in drivers who haven’t consumed alcohol or drugs.
It’s also important to consider cultural and language differences. Some drivers may misunderstand instructions due to language barriers or may be unfamiliar with the test format, further complicating the accuracy of the results.
Legal professionals often highlight these human factors when questioning the validity of field sobriety tests, emphasizing that the results aren’t purely scientific measurements but observations influenced by multiple variables.
By examining these human factors, attorneys can provide a fuller picture of why FST outcomes might not reflect true impairment, adding nuance to a DUI or DWAI defense strategy.
How Field Sobriety Test Results Can Be Challenged
Defense attorneys in Colorado employ a variety of strategies to contest field sobriety test results. Common approaches include:
Questioning the officer’s training or experience in administering standardized tests.
Highlighting environmental or medical factors that may have affected performance.
Challenging procedural errors, such as unclear instructions or improper documentation.
Using expert testimony to explain the limitations of FSTs and how external factors can influence results.
Reviewing video evidence from traffic stops to analyze the officer’s conduct and the driver’s performance.
By examining both the circumstances of the stop and the inherent limitations of FSTs, attorneys can reduce the weight of these tests in court proceedings.
Situations Where FST Results Are Particularly Contestable
Not all field sobriety tests are equally reliable, and certain situations increase the likelihood of contesting their outcomes:
Non-standard tests: Officers sometimes use informal or improvised tests that lack scientific validation.
Challenging terrain: Tests conducted on hills, gravel, or icy roads can compromise accuracy.
Drivers with disabilities: Individuals with physical or neurological disabilities may have difficulty performing standard tests.
Multiple stressors: High-pressure situations or distractions, such as traffic noise or other passengers, can affect test results.
Recognizing these scenarios allows defense attorneys to build a compelling argument that the FST results shouldn’t be considered conclusive evidence of DUI or DWAI.
Let Us Help with Field Sobriety Test Challenges
At The Leier Law Office LLC, we understand that field sobriety tests can be stressful and sometimes misleading. Serving Fort Collins, Colorado, as well as Loveland, Greeley, Windsor, and Evans, we approach each case with care and attention, helping our clients understand the factors that may affect test results.
By carefully examining the circumstances of the stop, procedural details, and other influencing factors, we work to provide guidance and support throughout the legal process. If you’re facing DUI or DWAI charges, reach out to us so we can help you explore your options and take the next steps with confidence.
