When someone is pulled over on suspicion of Driving While Intoxicated (DWI) in Montgomery County, Texas, law enforcement officers often rely on a set of roadside tests known as Standardized Field Sobriety Tests (SFSTs). These tests include the Horizontal Gaze Nystagmus (HGN), Walk and Turn (WAT), and One-Leg Stand (OLS). While these tests are supposed to help officers determine whether a driver is impaired, an inconvenient truth is that many completely sober people struggle to pass them. Consider the unfortunate arrest of a former Alsbrooks Law client – we’ll call her “Jenny”. Jenny left a Mexican food restaurant after enjoying a margarita with dinner, but she was arrested for DWI after performing poorly on SFST’s. Jenny is in her 60’s – she’s gotten a little clumsy with age, and she just didn’t do well on the roadside tests designed to make her look bad in front of a camera. Jenny wasn’t intoxicated – a blood test showed barely a trace of alcohol in her blood. Fortunately for her, Jenny’s case was dismissed. But what if Jenny had refused a voluntary blood test out of frustration with the unfair process? Montgomery County law enforcement could have brought her to trial based solely on the SFST performance and subjective opinions of one officer.
The studies that led to the adoption of these field sobriety tests have been criticized. The studies were conducted in highly controlled environments.
The real-world application of the field sobriety tests doesn’t mirror the original study conditions. Even within these studies, accuracy rates were far from perfect. in 1981 Tharp, Burns, and Moskowitz found that 32% of individuals in a laboratory setting who were judged to have an alcohol level above the legal limit were actually below that limit.
The Problems with the Horizontal Gaze Nystagmus (HGN)
The Horizontal Gaze Nystagmus test involves an officer moving a pen or light side-to-side in front of your eyes while looking for an involuntary jerking of the eyes, called nystagmus. The theory is that alcohol consumption exaggerates this eye movement.
However, several issues make the HGN test unreliable:
- Medical conditions like inner ear problems, neurological issues, or even fatigue can cause nystagmus.
- Environmental factors like flashing lights from police cars, passing vehicles, and poor lighting can interfere with the test.
- Officer training and bias can also affect results. If an officer already suspects you of DWI, they might subconsciously “see” what confirms their suspicion.
Why the Walk and Turn (WAT) Is Stacked Against You
The Walk and Turn test requires a driver to take nine heel-to-toe steps in a straight line, turn on one foot, and take nine steps back. It sounds simple enough, but even sober individuals often struggle with this test, especially under stressful conditions.
Common factors that affect performance include:
- Uneven or sloped surfaces like roadside shoulders.
- Poor weather or low visibility.
- Physical conditions like age, weight, or injuries.
- Nervousness and anxiety from being pulled over and scrutinized.
Even minor mistakes, like starting before instructed or miscounting steps, can be used as “clues” against you.
Police officers often berate accused citizens by telling them that the Walk and Turn test is “simple walking”, but there is absolutely nothing simple about a test that involves seven distinct instructions before you even get started walking the line.
The One-Leg Stand (OLS) Is No Better
The One-Leg Stand test asks a person to raise one foot six inches off the ground and count aloud until told to stop. Balancing on one foot while being watched by law enforcement, often in the dark or on uneven ground, is a challenge for anyone.
Factors that can impact this test include:
- Balance issues unrelated to alcohol.
- Footwear like boots, heels, or sandals.
- Roadside distractions.
- Pre-existing medical conditions.
The problem is that officers often fail to account for these factors, and any sign of imbalance will be interpreted as evidence of intoxication.
What You Should Know
Alsbrooks Law routinely challenges the reliability and administration of SFSTs in DWI cases throughout Montgomery County, Texas. If you’ve been arrested for DWI after roadside sobriety tests, it’s crucial to have an experienced DWI attorney review your case.
Contact Alsbrooks Law today for a free consultation.
Further Reading:
-Cole & Nowaczyk (1995)
“Field Sobriety Tests: Are They Designed for Failure?
–Rubenzer (2008)
“The Psychometrics and Science of the Standardized Field Sobriety Tests” — Published in Law and Human Behavior, this article critiques the psychometric properties (reliability, validity, standardization) of SFSTs. The author argues that the tests lack scientific rigor and that factors like officer expectancy bias and environmental conditions significantly affect results.
-Stuster & Burns (1998)
A NHTSA-sponsored field validation study that, while generally supportive of SFSTs, acknowledged limitations — including reduced reliability in poor environmental conditions, the influence of officer subjectivity, and challenges with older or physically impaired subjects.