Are field sobriety tests always accurate?

Field sobriety testing is something many people know about but few people understand. For example, many people don’t understand why an officer has someone walk in a straight line instead of just asking for a chemical test.

You have protection from unreasonable searches, which means that a police officer can’t just demand a chemical test during a traffic stop. First, the officer has to establish probable cause. They need to have strong reason to suspect that you are under the influence of alcohol. If you admit to having multiple drinks before getting in your car, that could be enough probable cause for an officer to ask you to perform a breath test.

However, in most traffic stops, a police officer will have a driver perform a series of field sobriety tests before they request a chemical test. A field sobriety test can potentially give an officer the grounds they need to request a chemical breath test. However, field sobriety tests can return unreliable results in certain cases.

Many personal factors can influence a field sobriety test

The way that you perform on a field sobriety test will reflect not just your level of impairment but also other factors. For example, those who are overweight may have a harder time walking neatly in a straight line, especially if they cannot see the placement of their feet in front of their abdomen.

Those who have joint issues or balance conditions like vertigo may struggle to perform a field sobriety test properly. Advanced age and even anxiety can impact how well someone follows directions or physically performs during a field sobriety test.

Officers don’t always perform the tests properly

There are many different field sobriety tests, but only three are widely recognized as the standardized field sobriety tests. If an officer performs the wrong kind of test or if they instruct the driver improperly, that could impact the accuracy of the results.

Whether you think that the officer didn’t do the test the right way or you think there is a medical explanation for your performance on the test, challenging the evidence the state wants to use against you could be part of a defense strategy. Learning more about the limitations and rules around field sobriety tests can help you decide the best way to defend yourself.