How Accurate Are Field Sobriety Tests Anyway?

Field sobriety tests (FST) are used to determine if a driver may be impaired. It is important to understand that an FST does not determine if you are able to drive, it gives an officer probable cause to conduct other, more invasive tests. Without probable cause, it can be difficult for an officer to justify asking for a breath, blood or urine test.

What is an FST?

A field sobriety test is a standardized test that usually comes in three parts.

• Eye test, called the Horizontal Gaze Nystagmus (HGN), where the officer will look for certain eye movements that indicate alcohol has been consumed.
• Walk and turn test, which is used to determine the driver’s ability to pay attention.
• One-leg stand, to determine the drivers balance ability.

Sometimes, an officer will use other tests like saying your ABCs or touching your finger to your nose. Those tests are more subjective and more arguable in court. Usually after these tests, an officer will then use a breathalyzer test to check the driver’s blood alcohol content (BAC).

Are FST admissible in court?

FSTs are used to determine probable cause for a breath test. Typically, a court doesn’t recognize the walk and turn or the one-leg stand as scientific fact. The HGN is usually used as evidence in court, because it is more scientifically reliable.

As for breathalyzer tests, some cases have found that, these can give inaccurate readings. The devices have strict calibrating operations and are overall very sensitive devices. This can, in some cases, make them unreliable.

If FSTs aren’t always used in court, why do they administer them?

FSTs are mostly used to establish probable cause for an officer to administer a more invasive test such as breath, blood or urine tests. An officer needs to have a legitimate reason to ask for one of these tests.

An officer is most cases, would not be allowed to pull you over and ask for a blood sample right away. Because a blood test is considered invasive, there needs to be a good reason and evidence to back up the officer’s reason to ask for this test.

Fighting and FST

All tests are “fight-able.” FSTs, breathalyzer, blood and urine tests can always be challenged if you feel they were administered incorrectly or you did not receive fair treatment from the officer.

If you can prove that any one of these tests was not administered correctly, the findings could be rejected as evidence against the charge.

If you do choose to challenge any test, it is wise to see legal counsel beforehand. An experienced defense attorney can investigate your case and help ensure that your rights are protected. Florida has strict drinking and driving laws, having an attorney who knows the Florida law and court system can make a world of a difference in your case.