DUI Investigation: Field Sobriety Tests Influence a DUI Arrest

Field Sobriety Tests. These tests, commonly referred to a FSTs, are one method police officers use to identify drunk drivers during a traffic stop. While conducting a driving under the influence, or DUI, investigation, a police officer requests that you follow specific instructions. For example, the officer may instruct you to stand on one leg for a specified number of seconds.

In theory, these instructions are simple, easy-to-follow and complete — only when sober. An individual under the influence of alcohol may have a more difficult time completing any of the FSTs and have trouble following instructions.

The Different Field Sobriety Tests

The Horizontal Gaze Nystagmus Test

This test attempts to determine if you are under the influence according to your eye movements. You have to follow an object only using your eyes. The object is typically a pen or penlight. The police officer will move the tiny object from one side to the other. In theory, a sober person will be able to follow directions without moving his or her head or show a jerking of the eyes. An intoxicated individual will not.

The One Leg Stand Test

This is a balance and coordination test where you have to raise your foot so many inches from the ground while counting for 30 seconds. The police officer will instruct you to keep your hands at your sides while you complete the test.

In theory, a sober individual will be able to raise his or her leg for 30 seconds without swaying or standing on both feet. An intoxicated person will have a problem doing so. If fact, an officer will look for signs of intoxication during the one leg stand test like:

  • The driver placing his or her foot on the ground.
  • The driver using his or her arms to keep from falling.
  • The driver swaying while trying to maintain his or her balance.

In the officer’s opinion, any of the above will be strong evidence of alcohol intoxication.

Walk and Turn Test

This type of field sobriety test is all about mental concentration and balance. You are required to walk in a straight line while placing the back of one foot in front of the other. In other words, walking heel-to-toe in nine steps, turning and walking heel-to-toe again.

Again, in theory, a sober person should be able to do this with no problem. An intoxicated individual would have a problem completing the test. The individual may use his or her arms to maintain balance. He or she may miscount steps. Instead of taking nine steps, he or she takes 10 or 11. The person may step away from the line the police officer has told him or her to walk on. The officer may determine the individual is drunk because he or she failed to properly follow instructions.

FSTs are not complete indicators of intoxication. You can do everything right and still be arrested for DUI based on the officer’s observations. Should you need a strong defense team in the Los Angeles area, contact the Law Offices of Jonathan Franklin to schedule an appointment for your free consultation.