Drunk Driving Defense Lawyer

Challenging the accuracy of the field sobriety tests

Michael J. Zarrella, Esq

Law Office Address:

127 Dorrance Street

Providence Rhode island 02903

Cell: 401-523-5271

Office 401-490-6820

Fax: 401-490-3207


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Rebuking the DUI field sobriety test results.


What are field sobriety tests in a DUI case?

There are three standard field sobriety tests that the police use to help themselves in a DUI investigation. These three sobriety tests are the horizontal gaze nystagmus test, the walk and turn test, and the one leg stand test. These tests are given in order to see if a driver is impaired. The prosecutors will attempt to use these test results as evidence of drug driving. However, all the tests are not dispositive of someone being drunk. Many sober people fail the tests, while sometimes drunk people pass them. These tests are just one tool the police will try to use to prove a DUI case.

A good lawyer can often discredit the field sobriety test. Many officers do not score the test properly or fail to instuct the driver the correct way before giving the test. Othertimes, a test can be discredited based on something else that caused the driver to fail such as injury, weather, ground condition, sickness, weight, and age just to name a few.

Horizontal gaze nystagmus test

The horizontal gaze nystagmus test checks the involuntary jerking of the eye, which can be caused by alcohol consumption to a point in which the drivers BAC is over .1.

The police officer will instruct the driver to follow the point of a pen with their eyes, while not moving their head. The test has 6 different clues that the police are looking for. If the police find 2 clues, the test is deemed to have been failed. There are 6 clues in the test;, 3 clues for each eye.

Lack of Smooth Pursuit - The police officer moves the pen or other simulis slowly from the center of the subject's face towards his ear. The eye should smoothly follow the object, but if the eye exhibits nystagmus, the officer notes the clue. The office willl do this test twice, one for each eye.

Distinct Nystagmus at Maximum Deviation - The officer moves the pen or other object toward the drivers ear, this will bring the eye as far over as possible, he then holds the the pen there for four seconds. The officer then looks for a distinct and sustained nystagmus in the driver's eye. The officer should have the pen remain at maximum deviation for at least four seconds, this will ensure that quick motion of the pen was not the cause of the nystagmus.This test is also done twice, once for each eye.

Onset of Nystagmus Prior to Forty-Five Degrees - The police officer moves the pen at a slow and steady speed until the object is past 45 degrees. If officer notes eye nystagmus before the pen reaches forty-five degrees from the center of the suspect's face, then that is consided a clue. The officer will check the other eye.

Walk and turn test

The walk and turn test is another standardized field sobriety test that the police use to assist themselves in a DUI investigation. The poice instruct the suspect driver to take nine heel-to-toe steps along a straight line. There after the suspect is directed to turn on one foot with three small steps and return in the same exact manner back. In this test, the police are looking for different clues.

The eight clues the police are looking for are as follows:

  • See if suspect cannot keep his or her balance during instructions;
  • See if the suspect starts the test too soon;
  • See if the suspect stops while walking;
  • See if the suspect doesn't touch heel-to-toe;
  • See if the suspect steps off line;
  • See if the suspect uses arms to balance;
  • See if the suspect performs improper turns or turns incorrectly; or
  • See if the suspect takes incorrect amount of steps.

If the suspect has two clues then he or she is deemed to have failed the test.

One leg stand test

The one-leg stand test is the third test that the police use in a DUI investigation. In this test, the suspect must stand on one foot with the other foot being approximately six inches off the ground. The suspect then will be told to count by thousands for thirty seconds. During this test, the suspect's arms must remain at his or her side. Finally, you must look down at your foot. The police officer will be looking for four different clues while the suspect takes this test. You could be arrested for driving under the influence of drugs or alcohol if you exhibit any of the following clues:

  • Putting his or her foot down before the test is completed;
  • Swaying while trying to maintain your balance;
  • Hopping while trying to maintain your balance; and/ or
  • Using your arms to help maintain your balance.

If the police observe more than two clues, then the suspect is deemed to have failed the test.


There are many ways to challenge the field sobrity test in a DUI or refusal case.

A good DUI lawyer knows that the Standard Field Sobriety Tests can be easily challenged.  The police and the state would like you to believe that the tests are a great indicator to determine whether one is drunk. This is simply not true.  There are many reasons that a person can fail a SFST.   Here are a few of the many examples that could cause a failed test:

  • Age;
  • Weight;
  • Sickness;
  • Nervous;
  • Fatigue;
  • Bad knees;
  • Bad back;
  • Concussion;
  • Failure to administer the test properly;
  • Failure to  grade the test correctly;
  • Failure to instruct properly;
  • Inner ear infection; and /or
  • Conditions for test were not proper to give the test.

The SFST can be effected by the following conditions:

  1. Rain/snow;
  2. Wet/Icy conditions;
  3. Wind;
  4. Cold;
  5. Uneven Pavement;
  6. Area not illuminated enough;
  7. Test were taken too close to traffic;
  8. Police car lights distracted the test; and/or
  9. Test was done in shoes with heels.

DUI Evidence: Top DUI Attorney

When law enforcement has improperly administered your DUI field sobriety tests, it can lead to mistakes in the results that are obtained. Any officer that does not administer the field sobriety tests correctly, will be cross-examined at length regarding his knowledge and qualifications to administer the test. Inadequate attention by police to proper procedures as well a lack of knowledge of the tests can often lead to a client receiving an acquittal or a reduction to a lesser charge.


You need a top Rhode Island DUI lawyer to help you with your DUI! Call Michael J. Zarrella, Esq. now.