Field Sobriety Tests

Fighting a DUI in Orange County, CA

After a law enforcement officer pulls you over on suspicion of drunk driving, the officer will likely ask you to undergo a breathalyzer test or several field sobriety test. These tests have all been approved by the National Highway Traffic Safety Administration (NHTSA) as methods for determining whether or not a driver is DUI. The evidence gathered from these tests is often enough to convict a driver of a DUI in a courtroom.

Field sobriety tests are one of the most common types of BAC testing used by law enforcement officers throughout Orange County, and the three tests that are the most common are the Horizontal Gaze Nystagmus, the Walk and Turn and the One Leg Stand.

Are Field Sobriety Tests Even Accurate?

These tests must be administered by a police officer in a certain manner that has been prescribed and standardized by the NHTSA, and cannot be used as evidence if certain requirements are not met. Poor performance in a field sobriety test is thought to be an indication that a driver is mentally or physically impaired from alcohol or drug consumption, but these tests have earned a reputation for being flawed and unreliable.

A study conducted by the U.S. Department of Transportation showed that even the most reliable field sobriety tests are only between 65-77% accurate in detecting if a driver is intoxicated or not. If you have been arrested for a DUI because you failed one or more field sobriety tests, it is critical that you seek the help of an experienced Orange County DUI lawyer who can help you fight your charges.

FST: Horizontal Gaze Nystagmus

Out of all of the field sobriety tests, the horizontal gaze Nystagmus test is presumed to be the most accurate. This test is given at a roadside DUI investigation and tests the involuntary jerking of the eyes that occurs when an individual's abilities are impaired because of the use of alcohol or drugs. Not only can the individual not control the jerking of their eyes, but they are also unaware that the jerking is happening. During this test, the officer will instruct the suspect to follow an object with their eyes as the officer moves the object from side to side. The officer will be looking for an early onset of the involuntary jerking of the suspect's eyes, such as at or before a 45-degree angle, which is a sign of high blood alcohol concentration.

One of the main reasons why this test is not foolproof is because there are several other factors that can contribute to horizontal Nystagmus in an individual, such as head injuries, tired eyes or foreign fluid in the body.

FST: Walk and Turn

The walk and turn test involves splitting the attention of a driver between mental and physical tasks that will reveal or indicate impairment. During the test, the officer will be judging how well the suspect can follow and remember directions while performing a variety of physical movements. An officer will typically order the suspect to take nine heel-to-toe steps on a real or imaginary line, pivot around, and then take nine heel-to-toe steps back. The suspect may also be asked to count the steps aloud and keep his/her arms down.

Some of the clues of intoxication that the officer will be looking for include:

  • Starting to walk too soon
  • Stepping off the line
  • Losing balance during instructions
  • Using arms to balance
  • Taking an incorrect number of steps

If a suspect displays two or more of these signs, the NHSTA reports that there is a high chance that the suspect has a BAC of .10% or greater. This test can be significantly more difficult when the ground surface is uneven or poorly lit, or when the officer's instructions are vague. Additional factors such as the suspect's weight, physical condition, and if they are injured or ill will also have a substantial impact on the results of the walk and turn test.

FST: One-Leg Stand

This test is also a "divided attention" test where the suspect must split their attention and follow instructions correctly. In the one-leg stand test, the officer will instruct the suspect to raise his/her foot off the ground approximately six inches and to hold still in that position while counting from 1001-1030. The officer will also instruct the suspect to look down at his/her feet while participating in the test. If the suspect uses his or her arms to balance, hops, sways, or puts his/her foot down while trying to balance and follow instructions, there is a high chance that they will be arrested for DUI. The NHTSA estimates that there is 65% chance that a driver who displays two or more of these clues will have a blood alcohol concentration above .10%.

Similar to the walk and turn test, there are many external factors that can play a role in a suspect's ability to correctly complete the one-leg stand test. If the suspect is wearing unstable footwear, is fatigued, ill, nervous, or confused about what to do, the test results can be inaccurate. Additional factors such as inclement weather, uneven surface conditions, and vague instructions from the police officer can also distort test results, and you must call an Orange County DUI lawyer who can investigate these factors on your behalf.

Orange County DUI Lawyer: Fighting for You

In addition to the three tests described above, law enforcement officers will sometimes use non-standardized field sobriety tests to aid in their DUI investigations and arrests. These tests can include the hand pat field sobriety test, the finger-to-nose field sobriety test, the Rhomberg balance field sobriety test, the finger count field sobriety test and more.

Here at the Law Offices of Jacqueline Goodman, we have extensive experience taking DUI charges to court and fighting field sobriety test results. We know how to investigate your DUI and question the validity of the evidence brought against you.

Call today and schedule a free consultation to learn more about how you can avoid California DUI penalties!