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Challenging Standardized Field Sobriety Tests as Inaccurate and Unreliable

There are few experiences that will raise your blood pressure more quickly than seeing flashing red and blue lights in your rear view mirror.  Many motorists pulled over by the police in Houston or Galveston counties have had little if any prior contact with law enforcement.  When you pull over and the officer approaches your vehicle, you may feel stress, fear or even anger.  However, if you have been drinking, what you do next can have a substantial impact on your future.  Many people pulled over after they having had a single drink presume that they will be arrested and hope that if they “cooperate” their chances of going home, rather than visiting the local jail, are better.  Generally speaking, nothing could be further from the truth.  When an officer pulls you over, often times their course of action is to develop evidence so that you do not go home.  It may be surprising to some, but DWI investigations are far less scientific and reliable than many drivers realize.  Most people have seen officers pull over drivers and administer standardized field sobriety tests (SFSTs) on television police dramas, but what most people do not realize is that an experienced DWI attorney may be able to effectively challenge both the legal basis for the stop and the SFST results.

A law enforcement officer may not pull you over on a mere hunch but must have a sufficient legal basis to justify the stop.  In most cases, this will either be a “reasonable suspicion” that a crime is being committed, such as observing you speeding or observing erratic driving behavior.  It is important to keep in mind that just because a law enforcement officer stops you does not mean that he or she has sufficient legal basis to conduct a DWI investigation.  Although speeding is a violation that permits an officer to pull you over, speeding is not evidence of intoxication.  The officer may detain you to write a traffic citation but does not have probable cause to conduct a DWI investigation which would include having you perform SFSTs.  If you are calm and provide your license and insurance information without engaging in a prolonged conversation you may well drive away from the encounter.  However, even if you have just had one drink, if the officer observes any signs of slurred speech, the odor of alcohol, red watery eyes or observes an open container of alcohol in the car—you may find yourself in the middle of a DWI investigation.

Even if you have only had one drink, it can be a serious mistake to engage the officer beyond producing your license and insurance information and providing brief concise answers to any questions.  It is never a good idea to admit you have been drinking or that you are coming from a bar.  The legal requirement for an initial stop is only that the officer has “reasonable suspicion” that a crime is being committed based on articulable facts.  This is a lower burden than the “probable cause” needed to conduct a DWI investigation.  The key to keep in mind is that the officer must have probable cause to believe you are driving under the influence of alcohol to initiate a DWI investigation and ask you to perform SFSTs.  If the officer only stopped you for speeding, then the officer may have no evidence supporting that you are driving under the influence because speeding is not evidence of DWI.  If you keep your interaction brief and provide short concise answers, the officer may not observe sufficient physical evidence of intoxication to ask you to take SFSTs.

Also remember, even if the officer does ask you to perform FSTs, you do not have to perform them.  If you have not been drinking and are not in a rush, you may choose to perform the tests, but they can be difficult and many people who are not intoxicated fail.  If you have been drinking, it is best to avoid the tests because their sole function is to provide evidence supporting probable cause for a DUI/DWI arrest.

Regardless of which route you take, any driver who agrees to take SFSTs should be aware that these tests are physically difficult and extremely inaccurate.  Although you may have seen many versions of field sobriety tests on television, there are only three that have been approved by the National Highway and Traffic Safety Administration (NHTSA) as being reasonably accurate at identifying intoxicated drivers.  While you may be familiar with any of these tests only the first three listed below have any validity according to the NHTSA:

  • Walk and turn
  • One-leg stand
  • Horizontal gaze nystagmus test
  • Reciting the alphabet
  • Counting backwards
  • Alternating touching your nose with a finger first with one hand than another
  • Standing with your feet together and head tipped backwards
  • Indicating the number of fingers held up by the officers

While it might be surprising to learn that only the first three tests have any legitimacy, most people do not realize that even those three are extremely inaccurate even when performed perfectly by a properly trained law enforcement officer who is fully trained in accurately demonstrating, explaining and scoring the tests.  Many officers submit subjective analysis for the objective scoring system or fail to follow the precise guidelines and procedures when demonstrating and explaining the SFSTs.  Even when all of this is done perfectly, which is not nearly as often as you might expect, the three SFSTs approved by the NHTSA still have a high failure rate.  The NHTSA acknowledges that the walk and turn and one-leg stand inaccurately identify someone as intoxicated 35 percent of the time while the horizontal gaze nystagmus test falsely identifies someone as impaired 23 percent of the time.

As a former police officer, I have conducted many DUI/DWI investigations and recognize the common mistakes made by officers when administering the tests.  I ensure that the jury also is well aware of the high rates of false positive results for intoxication produced by SFSTs even under the best of circumstances.  I also use my experience working in law enforcement on such cases to expose common errors made by officers when providing instructions and demonstrating the tests.  The tests must be precisely demonstrated and explained to be valid so my past experience as a patrol officer is valuable to clients in identifying and exposing clear departures from appropriate procedures and protocol.

I also know that the physical exercises that constitute SFSTs are highly unnatural and require a fair degree of physical fitness, balance and coordination.  I educate the jury on how foreign and unnatural these tests are for anyone who is unfamiliar with them.  The tests are all the more difficult if you suffer from obesity, a physical disability, diabetes, vertigo or other physical or mental disabilities.  I make certain a jury understands such physical and mental limitations and their potential impact on SFST results.

Many people arrested and charged with driving under the influence/driving while intoxicated presume that the DUI investigation process is based on a firm scientific basis.  What one should take away from this article is that there is an enormous margin of error in DWI investigations that permit a skilled criminal defense attorney with a background in law enforcement to protect your freedom and future.  If you are convicted of DUI/DWI in Houston, Galveston, Brazoria or Fort Bend counties you may suffer serious adverse consequences, including incarceration in county jail or state prison, substantial fines, installation of an ignition interlock device, probation, mandatory alcohol classes, driver's license suspension or revocation, community service and other penalties.

Aggressive DWI Defense: Texas DWI Lawyer

If you are arrested for driving under the influence in Houston or anywhere throughout Harris, Galveston, Brazoria or Fort Bend Counties, Lori Elaine Laird provides a unique combination of investigative skills acquired as a former police officer and the legal experience and expertise of a successful criminal defense attorney. Call (832) 699-1966 today for your confidential consultation or browse our DWI practice area on our website for more information regarding our DWI defense strategies.

Lori Elaine Laird

Former police officer. Aggressive, experienced trial attorney.


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