Field sobriety tests (FSTs) may be used by law enforcement officers to assess whether a driver is under the influence of alcohol or not. However, it is important to recognize that these tests have limitations and can be an inaccurate way of determining the presence of alcohol in a person's system.
Here are some reasons why FSTs may not always provide reliable results.
Subjectivity
FSTs often rely on the subjective judgment of the administering officer. The interpretation of a driver's performance during these tests can be influenced by the officer's biases, training, and experience. This subjectivity introduces the potential for errors and inconsistencies in the assessment.
Physical and Medical Conditions
Various physical and medical conditions can affect an individual's ability to perform FSTs accurately, leading to false results. Factors such as age, weight, physical disabilities, injuries, fatigue, and certain medical conditions can impact balance, coordination, and cognitive functioning, even in the absence of alcohol impairment.
Nervousness and Anxiety
Being pulled over by law enforcement and asked to perform FSTs can be a nerve-wracking experience. Nervousness and anxiety can affect a person's performance, leading to false indicators of impairment during the tests.
Lack of Standardization
While FSTs have standardized procedures, variations can occur in the administration and interpretation of these tests across different jurisdictions and officers. Inconsistencies in administration techniques, environmental conditions, and scoring criteria can impact the reliability of the results.
Poor Test Accuracy
Some FSTs have been found to have a lower level of accuracy in detecting alcohol impairment. For example, the horizontal gaze nystagmus (HGN) test, which assesses eye movements, can be influenced by factors other than alcohol, such as certain medications or medical conditions. Similarly, the walk-and-turn and one-leg stand tests rely on divided attention and physical coordination, which can be challenging for individuals, even when sober.
Lack of Scientific Validation
The scientific validity of FSTs has been a subject of debate. While some studies suggest a correlation between FST performance and alcohol impairment, there is a lack of consensus on the accuracy and reliability of these tests as indicators of specific blood alcohol concentration (BAC) levels.
Considering these limitations, it is important to note that FSTs are often used as initial screening tools to establish probable cause for further testing, such as a breathalyzer or blood tests, which provide more objective measures of alcohol impairment. If you have been charged with a DUI (driving under the influence), contact a DUI defense attorney for help with your case.
