Unmatched Skill. Unwavering Advocacy.

Santa Rosa Field Sobriety Tests

Field Sobriety Tests in Santa Rosa

Preparing for Field Sobriety Tests in DUI Stops

It happens to a lot of drivers. You head home after drinking a few beers because you can make it home safely. Before you know it, you hear that blaring siren and see those notorious flashing red and blue lights coming up behind your vehicle.

If you’ve been arrested on suspicion of a DUI, chances are you had to undergo a field sobriety test. You probably have questions about the types of tests administered and the bearing they have on your case.


Worried about how field sobriety tests might affect your DUI case in Santa Rosa? Call Wilber Law Offices, P.C. today at (707) 986-4482 or contact us online to protect your rights from the start!


Standardized and Non-Standardized Field Sobriety Tests

Law enforcement agents routinely administer field sobriety tests to motorists to determine whether they are drunk or otherwise impaired while behind the wheel. These tests are usually given before a breathalyzer test. They challenge a driver’s balance, coordination, memory, motor skills, and ability to focus.

If a police officer concludes, based on the results of these tests, that you were driving with an unlawful amount of drugs and/or alcohol in your system, it establishes probable cause to arrest you. The results of these tests are also admissible as evidence in court.

The National Highway Traffic Safety Administration (NHTSA) has hand-picked and endorsed standardized tests. The organization has identified three tests that supposedly accurately predict impairment: the horizontal gaze nystagmus test, the walk-and-turn test, and the one-leg stand test.

Horizontal Gaze Nystagmus

Horizontal gaze nystagmus is an involuntary jerking reaction that happens to everyone when our eyes gaze peripherally. But this reaction intensifies when someone is impaired by alcohol. To determine if a person is intoxicated, an officer will pass a hand-held object – a pen, flashlight, etc. – in front of a motorist’s face and instruct them to follow the object with their eyes. When doing so, officers will look for specific indicators of impairment, like distinct and exaggerated jerking, at what angle the jerking begins, and if your eyes can’t follow the object smoothly.

If several of these signs appear at once in your case, an officer has reason to assume you have a BAC of .10% or higher.

The Walk-And-Turn Test

To conduct this test, an officer will request that a driver place their hands at their sides and walk nine steps straight, heel-to-toe. Then, the motorist will be asked to turn around and repeat these steps. During the test, the officer will be looking for several signs of impairment:

  • Stepping out of line
  • Turning improperly
  • Taking an incorrect number of steps
  • Raising your arms to stay balanced
  • Losing balance while turning
  • Not touching heel-to-toe
  • Beginning the test before instructions are finished

NHTSA verifies that if two or more of the above signs are present during a test, there is a high likelihood that a motorist’s BAC is beyond the legal limit (.08%).

One-Leg Stand Test

The one-leg stand test, also known as the “divided attention” test, requires a motorist to stand with one foot about six inches off the ground with their hands planted at their sides. In some circumstances, an officer may request you to count while doing so, while others may not. If a driver sways while attempting to balance, hops up and down, puts their foot down several times to steady themselves, or otherwise struggles to complete the test, an officer may be able to conclude they are impaired.

If a driver shows any impairment during the above field sobriety tests, an officer will ask them to take a breathalyzer or chemical test to confirm their BAC is above the legal limit.

Officers also sometimes administer non-standardized field sobriety tests. These include asking drivers to recite their ABCs, count on their fingers, touch their fingers to their noses, or recite numbers backward.

The Reliability of Field Sobriety Tests

Although field sobriety tests are widely accepted as evidence in DUI cases, offenders and attorneys continue to pose a question: are field sobriety tests an accurate method of determining impairment? According to many researchers, the answer is no.

To establish a more uniform DUI arrest process, the National Highway Traffic Safety Administration (NAFTA) requested that the Southern California Research Institute (SCRI) develop standardized tests that all police departments could quickly adopt. Ultimately, the school concluded that the three standardized tests were suitable for administering to assess impairment.

A section of a study submitted by the SCRI recorded how effectively police officers could correctly gauge impairment. The results were shocking. The findings concluded that the officers correctly assessed an individual’s impairment only 47% of the time. So, nearly half the time, an officer could provide a false assessment of impairment, and it would be admissible in court. The study attributed the disappointing results to the officer’s failure to follow directions thoroughly. They did not score the tests repeatedly and adequately ignored evidence that indicated factors other than impairment caused drivers to fail.

In response to this study, NAFTA ordered the institute to conduct tests again after all officers had been trained to issue standardized tests. The studies showed improvement, but not enough for many experts and legal professionals to believe that these tests are valid methods of determining improvement.

Factors That Can Affect Field Sobriety Test Performance

Several physical, medical, and environmental factors can influence how a person performs on field sobriety tests, sometimes leading to inaccurate conclusions of impairment. These factors include:

  • Medical conditions: Inner ear problems, neurological disorders, or muscle weakness can impair balance and coordination.
  • Fatigue or anxiety: Being overly tired or nervous can affect concentration and physical stability.
  • Environmental conditions: Uneven, slippery, or poorly lit surfaces can make it challenging to complete the tests correctly.
  • Age and physical fitness: Older adults or individuals with injuries may naturally struggle with balance and coordination tasks.
  • Use of prescription medications: Certain medications can cause dizziness or impair motor skills without alcohol involvement.

Understanding these factors is essential, as they can create reasonable doubt about whether a failed test indicates intoxication.

Legal Rights During Field Sobriety Testing

It is essential to know that drivers have specific rights during a DUI stop, including when field sobriety tests are requested. While refusing to take a field sobriety test is generally allowed, there may be legal consequences, such as license suspension under implied consent laws, depending on the state. Additionally, drivers have the right to remain silent and do not have to volunteer information beyond what is legally required. Officers must administer tests fairly and consistently; any deviation could be grounds for challenging the test results in court. Awareness of your rights can help protect your case and prevent self-incrimination during a stressful encounter with law enforcement.

Don’t Let Mistakes in Sobriety Testing Jeopardize Your Case

The results of your field sobriety tests are crucial to the outcome of your case. However, if an officer strayed from regulatory processes and conducted these tests improperly, your charges could be reduced or even dismissed.

This is why it’s crucial that you immediately contact an attorney. The sooner a lawyer can start on your case, the sooner the attorney can build a solid defense. A DUI is a serious charge that requires aggressive and experienced representation.

The DUI and criminal defense attorneys at Wilber Law Offices, P.C., have represented numerous clients charged with misdemeanor or felony DUI and have helped them get their sentences reduced or charges dismissed. They will help you do the same.


If you’re facing DUI charges in Santa Rosa, don’t wait—reach out to Wilber Law Offices, P.C., your dedicated Santa Rosa DUI lawyer, for experienced defense and personalized legal support!


Case Dismissed
Case dismissed on eve of trial.
  • Case Dismissed
    Case dismissed on eve of trial.
  • Case Dismissed
    Case dismissed after filing, and before hearing on a motion to suppress evidence.
  • Favorable Outcome
    Client accused of possession of narcotics for sale was convicted at jury trial – Prior to trial, the only offer extended to client was straight prison time. After trial, successfully argued to the court that client should be granted probation with the opportunity to go to ...
  • “Ryan Wilber & Wilber Law Offices helped me a lot (and that’s an understatement!) He was able to negotiate a deal for me that saved my career and kept me out of serious trouble. They are the best in Santa Rosa / Sonoma County.” - William H.
  • “One of the best experiences in my life. Professional, courteous and understanding through whole process.” - Scott J.
  • “I’ve known Ryan for the better part of 20 years, he is very passionate about his work and it shows!” - Beau K.

Contact Our Firm

Schedule Your Consultation Today

  • Please enter your first name.
  • Please enter your last name.
  • Please enter your phone number.
    This isn't a valid phone number.
  • Please enter your email address.
    This isn't a valid email address.
  • Please make a selection.
  • Please enter a message.