Field sobriety tests aren’t all that scientific

When a driver is given a breath test or a urine test, it feels like a scientific process. A device is looking at the chemical makeup of that person’s blood to determine their blood alcohol concentration (BAC). These results are then regarded as a scientific fact that can be used in court to show that the driver was impaired.

But another tactic that police officers use is to give people field sobriety tests. These include the horizontal gaze nystagmus (HGN) test, the walk-and-turn test, and the one-leg stand. They are all designed to determine if someone is impaired because that individual won’t be able to perform these tests as well as a sober driver. But is this actually a scientific process that is trustworthy?

The accuracy rates are concerning

The truth is that field sobriety tests are notoriously inaccurate. They often produce the wrong results and sober drivers can certainly fail these tests. It’s also possible for impaired drivers to pass the tests. There are just a lot of different factors in place.

For example, someone may have trouble passing the one-leg stand test because they suffer from vertigo or other balance-related issues. Maybe they have a head cold. Maybe they are overweight and so physical balance is simply difficult for them. Perhaps they’re trying to do the test on a dark, rainy night on the side of the road. All of these factors – and many more – can make them appear to be impaired even when they haven’t been drinking at all.

Because the false positive rates for field sobriety tests are so high, it’s very important for drivers who have been arrested to know about all of the legal defense options they have.