Field sobriety tests exist as one of many tools in an officer’s DUI arsenal. They often use it as a means to tell if they need to implement further testing, such as breath or blood analysis tests, which often give more accurate results at the risk of more intrusive collection methods.
But standardized field sobriety tests did not always exist. So how did they come into being, and what purpose do they serve officers?
Standardized vs. non-standardized
According to VeryWell Mind, there are two types of field sobriety tests. This includes standardized and non-standardized. Standardized tests see more use now, despite the fact that only three tests qualify as standardized. These include the horizontal gaze nystagmus test, the walk-and-turn and the one-legged stand. By comparison, there are dozens of non-standardized tests.
This is simply due to the fact that it is harder to qualify a test for nationwide standardization. It must undergo a process of review, which would take plenty of effort and time that officers already run short on.
Why standardization is crucial
But why use standardized tests at all? Simply put, field sobriety tests have a big flaw in the form of officer bias. These tests do not rely on science to draw conclusions. Instead, it relies on an officer’s observation of a driver. This is the only way to tell if a driver passed or failed, and an officer’s inherent bias could skew the results.
Standardization got introduced in an attempt to keep bias out of test results. Officers have to check a driver’s reactions against a unified rubric, rather than it ending up left entirely to their decision. While this has gone a long way to help, officers and courts alike understand that these tests continue to have glaring flaws that may affect results.