Field Sobriety Tests

In the great majority of OWI cases an officer will have the suspected impaired driver perform various tests for impairment at the scene of the stop.  While there are legal defense issues related to when, where an how an officer may request or require a suspect to perform these tests, the administration and scoring of the tests is almost always an issue when determining whether an officer had sufficient legal basis to request an on scene preliminary breath test (PBT), to request an alcohol test (breath, blood or urine) and to arrest. 

  Surprisingly, officers who are trained and certified to administer these tests often make serious errors in the administration and scoring of the tests.  It is important to have an attorney who thoroughly understands the field sobriety tests, how they are to be administered and how they are scored if a person wishes to challenge an officer's determination of impairment in an OWI case. 

  The basic standardized field sobriety tests are a battery of three tests designed by the National Highway Traffic Safety Administration (NHTSA).  They are used to legally justify an officers arrest decision and demand for an alcohol test which would be admissible in court, generally in conjunction with an officer's alleged observations of driving, personal appearance and demeanor, and any preliminary breath testing results.  The three standardized tests can be further divided into the balance and coordination tests and the horizontal gaze nystagmus test.


The Horizontal Gaze Nystagmus (HGN) Test / "Eye Test":

     In this test the officer is supposed to look for small, distinct and involuntary jerking of the eyeball which, although occurring naturally in all people, becomes pronounced with increased levels of depressants such as alcohol, benzodiazepine class drugs (e.g. Valium, Xanaz, Ambien) and muscle relaxants.  The high number of arrests supported by a finding of HGN in individuals charged with OWI by use of THC (marijuana), narcotics and amphetamines which do not cause HGN is a testament to how subjective the evaluation of the HGN test and how officers are often able to find the results they believe they should be seeing in this test.  This is reportedly the most reliable of the three field sobriety tests and the one that officers most often administer improperly.

  Nystagmus may be caused by a wide variety of illnesses, disabilities, non-impairing medications and even such things as having rapidly moving objects or rotating lights in a person's field of vision while the test is being administered.  Additionally, officers are trained to hold and observe nystagmus for a prolonged period of time at maximum deviation because HGN at maximum deviation commonly occurs in sober people for a short period of time, failure to hold the eyes at maximum deviation to observe HGN for a minimum of four seconds on each eye may result in an improper finding of HGN.


Balance and Coordination - Divided Attention Tests

     The Balance and coordination field sobriety tests are also known as "divided attention tests."  An officer seeks to develop evidence of impairment not only by having a suspect perform difficult balancing acts but also seeing if the suspect fails to pay attention to and follow all verbal directions given while having the person balance in an unnatural posture and watching the officer's physical demonstration of the test.  What officers fail to do is advise a person that any deviation from the directions or the officer's demonstration ( e.g. raising arms more than six inches, starting before being told to start, not turning with a pivot) will be counted as an indicator of impairment.

  The NHTSA field sobriety test training manuals that all officers are taught from note several environmental and physical factors that can adversely impact a person's performance on the standardized field sobriety tests regardless of sobriety.  The balance and coordination tests should be administered on a "reasonably dry, hard, level, nonslippery surface.  Research by the NHTSA has demonstrated that "individuals over 65 years of age, [and those who suffer from] back, leg or inner ear problems had difficulty performing the Walk & Turn and One Leg Stand tests.  Furthermore, officers are taught to give people the opportunity to remove shoes or boots with heels higher than two inches as that may effect a person's ability to balance.  Officers or others moving in close proximity to a suspect performing the test may also have an adverse impact on a person's ability to perform the test.  Individuals who are 50 or more pounds overweight will also have difficultly performing the One Leg Stand test, regardless of impairment. 


The Walk and Turn Test / "walk a straight line test":

     The walk and turn test requires that a person balance in an unnatural position with their arms at their side and not taking a single step until the officer administering the test asks if the suspect has any questions and tells the suspect to begin.  At that point the person must take nine steps in a strait line, touching the heel of one foot to the toe of the other foot on each step, in a straight line, while counting the steps out loud and not pausing.  At the end of nine steps, the test subject must turn taking small, choppy steps with their outside foot, while pivoting on the other foot and not picking it up, turning 180 degrees around before repeating the process taking nine steps back. 


The One Leg Stand Test

     This test requires that the subject remain standing with their arms at their side and one foot in front of the other while the officer demonstrates the test and gives directions.  The suspect is then told to raise one foot six inches off the ground and to count out loud to 30 while looking at the tip of their raised foot.  A person will be deemed to show signs of intoxication if they put their foot down before being told to, raise their arms for balance, hop, or sways while performing the test. 


Non-Standardized Tests:

     Often officers will ask suspects to perform additional tests which are not part of the standardized field sobriety test battery.  This is either because the officer wants further evidence of intoxication or because they don't feel that the suspect performed as badly on the field sobriety tests as they should have based upon the officer's assumption of intoxication.  Common additional tests include asking a suspect to recite the alphabet from one letter to another without singing it, such as say the alphabet from D to P without singing it.  While the inability to recite the alphabet can be powerful evidence of impairment to a jury at trial, people are just not accustomed to reciting the alphabet without singing and just part of the way through under high stress situations like an OWI investigation on the roadside. Officers will sometimes ask a person to count from one number backwards to another number. 

  Sometimes officers will ask silly questions such as "how older were you in the year you were born" or simply ask a direct question such as asking for a person's date of birth while a person is answering a completely unrelated question posed by the officer.    One very common technique officers use to "obtain evidence of impairment" (or generally try to trip people up who are dealing with a stressful encounter with law enforcement) is to start asking questions while a person is performing some task, such as obtaining vehicle registration, to see how the driver deals with dividing their attention between a task and various questions. 

  These tests do little to demonstrate an impaired ability to drive or a prohibited blood alcohol concentration, however drivers should be aware of ways in which law enforcement officers will routinely try to confuse and misdirect suspects in order to create evidence of impairment to support a prolonged investigation and arrest determination. 


The Preliminary Breath Test:

     In Wisconsin an officer who believes he has evidence of an impaired driving offense may request that a suspect breath in to a mobile, preliminary breat test machine ("PBT").  The law prohibits the use of PBT results at trial for the purpose of establishing that a person was driving while impaired and motorists are not required to perform a PBT.  However, the results of a PBT may be used to bolster an arresting officer's basis for the initial arrest and decision to request a statutorily authorized breath, blood or urine test, the results of which may be used at trial.  Wisconsin appellate courts have also held that a suspects refusal to cooperate with a PBT may be considered as an additional factor weighing in favor of finding that an officer had probable cause to initiate an arrest for an OWI offense. 

 House Law Office - J. Steven House - 608.443.7522 - jshouse@jshouselaw.com - 222 S. Hamilton Street, Suite 12, Madison, WI 53703