Field sobriety tests are a standard part of a drunk driving traffic stop. Before a police officer arrests someone on suspicion of a driving under the influence (DUI) infraction, they will first try to verify someone’s impairment. After talking with a driver, an officer may ask them to step out of the vehicle to perform field sobriety tests. How well someone does on those tests will help to determine if they end up heading home or spending the night in jail.
Field sobriety tests often indicate someone’s reduced capability and can give an officer the probable cause they need to request a chemical breath or blood test. In some cases, such as when someone refuses a breath test, field sobriety test results may be a major part of the state’s case against them. With that said, these tests are far from infallible. These are some of the circumstances under which it may be possible for a defendant’s attorney to challenge the inclusion of field sobriety test results in a DUI trial.
1. When there isn’t video footage
Some officers have body cameras, and most police vehicles also have dashboard cameras. There should therefore be video footage of the field sobriety test that can affirm an officer’s version of events or show that they perhaps exaggerated. When there isn’t video footage of someone doing the field sobriety test, it may be easier for a lawyer to challenge the reported test results in the criminal trial.
2. When the officer uses an unusual test
In theory, there are many behaviors that might indicate alcohol impairment, but not every test is as reliable as people might think. When officers deviate from the three tests considered standard, including the walk-and-turn test, the one-leg stand test and the horizontal gaze nystagmus test, the results of those tests may not hold up under scrutiny in court.
3. When there is an explanation for someone’s performance
Neurological conditions, issues with motor control or even anxiety disorders can all compromise someone’s performance on a field sobriety test. Defendants who have a medical explanation for their poor performance might be able to convince the courts to disregard field sobriety test results when responding to their DUI charges.
Learning more about the rules that apply to the evidence used in DUI cases from a legal professional can help those who are hoping to avoid a criminal conviction.