This is Part II of our multi-part blog post discussing important information that drivers should know about field sobriety tests (FSTs) if they are stopped after consuming alcohol.  Part I of this blog provided an overview of the types of FSTs that may be administered whereas Part II focuses on key issues relevant to effectively challenging FSTS and minimizing their impact in your Texas DUI prosecution.

The starting point for any analysis of mitigating the impact of FSTs is the knowledge that these tests are completely voluntary.  When the police officer indicates that he or she wants you to participate in FSTs, he will probably not do so in a way that feels particularly like it is totally up to your discretion.  When the person making the “request” is wearing a gun and uniform with the power of arrest, it is not surprising that many motorists assume that they have no right to refuse to perform FSTs.

However, these voluntary exercises are optional and designed to create probable cause for a DUI arrest.  Generally, you should politely indicate you would prefer not to participate unless you are in good physical condition and have had absolutely nothing to drink.  Even under these circumstances, there is little to be gained by participating because FSTs are usually part of a “self-fulfilling prophecy.”  The police officer believes you will fail because you are intoxicated, and this perception will color his evaluation of your performance.  If you already were arrested for DUI and elected to participate in FSTs, here are some common defenses:

Non-Standardized Sobriety Tests Have No Probative Value:

The defense to these types of field sobriety tests is pretty straightforward.  These tests were determined by the National Highway Traffic Safety Administration (NHTSA) to have no reliability in accurately identifying drivers under the influence alcohol.  Because properly trained officers will be aware that these tests offer little more accuracy than calling heads on a coin flip, these tests will usually be conducted as a supplement to the Standardized Field Sobriety Tests (SFSTs).

Unreasonably High Error Rate for Individual SFSTs:

While SFSTs have more accuracy than non-standardized tests, there are many studies that show they are still highly unreliable as an indicator of alcohol impairment.  The accuracy rate of the walk and turn test, for example, is a mere 65 percent according the NHTSA.  In other words, it is only 15 percent more accurate than a coin flip.  The walk and turn is only slightly better at 68 percent while the Horizontal Gaze Nystagmus is only 77 percent accurate.  These error levels do not remotely approach the “reasonable doubt” standard.  When an experienced Texas DUI defense attorney represents clients, he effectively communicates this lack of reliability to a judge or jury.

Lack of Proper Officer Training:

The huge margins for error reflected above are based on SFSTs conducted by experienced police officers under optimal conditions.  The procedures required to properly administer SFSTs are extremely detailed, including a precise demonstration of the walk and turn and one leg stand before asking a motorist to perform these exercises.  Many officers lack adequate training so they may conduct the tests improperly or fail to evaluate the performance of a motorist accurately.  This further compromises the reliability of individual field sobriety tests that are fairly unreliable even under optimal conditions.

Fictional Ordinary Person Standard:

Just as the accuracy of the three SFSTs are based on proper administration of the tests by an officer fluent in conducting these exercises, the results indicated above for individual SFSTs also are based on assumptions about a DUI suspect.  The FSTs assume a healthy person within an average range for weight and age.  Drivers who are over 65 or more than fifty pound overweight may have their results impacted adversely when performing SFSTs.  These factors must be communicated effectively to the judge or jury when they are relevant.

Medical Conditions or Injury:

There are many health conditions or injuries that can impair a motorist ability to effectively perform field sobriety tests.  Anyone suffering from a leg or knee injury, for example, might be expected to struggle with the one leg stand and/or walk and turn.  Similarly, DUI suspects with the flu may have a difficult time focusing or remaining balanced.  If you have a medical condition or injury that may inhibit your performance but elect to take SFSTs anyway, you should inform the officer prior to participating in the exercises.

Environment/Clothing:

Sometimes factors like women wearing high heels, wet ground or extreme heat may impact SFSTs.

Individual Ability:

SFSTs presume that people are comparable in terms of physical ability.  Even if a DUI suspect is not ill or injured, some people are naturally clumsier or less coordinated.  These individual factors can explain a failed FST as well as intoxication in many cases.

While this certainly is not an exhaustive list of defenses that Texas drunk driving defense attorney Alex Tyra may raise to undermine the significant of field sobriety testing, this overview does illustrate a broad range of potential issues that may be raised.  Texas DUI attorney Alex Tyra offers a free consultation during which he can advise you about your legal rights and potential strategies for avoiding a DUI conviction.  We invite you to contact us in our Longview office at 903-753-7499 or visit our website and submit a case contact form.