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DWI Standardized Field Sobriety Tests (SFSTs)

Getting pulled over on suspicion of driving under the influence is stressful.  You might feel isolated if you do not have the right team behind you when facing criminal charges.  The legal team at the Westbrook Law Firm is here for you.

With more than 20 years of experience in your corner,  we will fight for you to obtain the best outcome possible for your DWI charge.

Contact us today at 281-888-5581 to schedule a free and confidential consultation.  We offer top-notch legal representation for people accused of driving under the influence of drugs and alcohol across Southeast Texas.

NHTSA Field Sobriety Test Manual

The National Highway Traffic Safety Administration (NHTSA) has published a manual that is used to train law enforcement officers to conduct “Standardized Field Sobriety Tests” (SFSTs).  These SFSTs are used by all law enforcement to determine alleged signs or clues of intoxication.

Some of the most noticeable “signs” or “clues” of impairment include:

  • Blurry vision
  • Imbalance
  • Inability to process information or instructions
  • Poor judgment
  • Minute muscle movement
  • Lack of coordination

These signs of intoxication can also mimic other physical conditions.  Skilled DWI Defense Lawyers can review surrounding facts to determine if the driver was under the influence or if they were suffering from a complication of a preexisting medical condition or conditions.

Horizontal Gaze Nystagmus Test (HGN)

The HGN test is used to identify any involuntary eye movements.  When a driver is under the influence of drugs or alcohol, they have unconscious eye movement.  Their eyes will involuntarily jerk or twitch. The more alcohol in a driver’s system, the more their eyes will jerk.

After a driver is pulled over, the officer will ask them to step out of their vehicle.  The officer will likely request that the driver move away from any flashing lights for accuracy.  The officer uses a pin light pointed at the driver’s eyes and moves it from left to right.  The officer watches the driver’s eye for sudden jerks.

HGN tests are only 88 percent accurate, so they are often challenged in court for reliability.

One Leg Stand Test (OLS Test)

The OLS test is straightforward.  The officer pulls over a driver who is suspected of driving while intoxicated and asks them to lift their leg six inches and balance themselves.  The objective of an OLS test is to determine whether a driver can focus on two tasks at once — standing on one foot and balancing themselves.

The OLS test is used to uncover common signs of intoxication. Some common signs of being under the influence of drugs or alcohol may include the following:

  • Unable to keep one foot in the air
  • Swaying from side-to-side
  • Hopping while on one foot
  • Moving arms to keep balance

DWI defense attorneys often challenge the validity of these OLS tests.  There are plenty of physical conditions, not including intoxication, that can cause a driver to fail an OLS test.  Proof of physical disability could be a viable defense to a poor OLS test.

Walk and Turn Test (WAT Test)

WAT tests are similar to OLS tests because they also test for a driver’s ability to perform multiple tasks at once.  The WAT test takes the OLS test a step further by also testing coordination.  The police officer will ask the driver to take several heel-to-toe steps while walking in a straight line.  When the driver gets to the final step, the officer instructs them to turn on one foot, take a series of small steps, and return to the starting point.

When administering the WAT test, the officer is looking for several clues of intoxication.  Examples of what the WAT test is searching for include:

  • The driver stops walking before making enough steps
  • The driver starts walking before being instructed by the officer
  • The driver is visibly off-balance
  • The driver cannot walk a straight line
  • The driver cannot walk heel to toe
  • The driver uses their arms to keep their balance
  • The driver takes too many steps
  • The driver falls down

Like other field sobriety tests, WAT tests are not 100 percent reliable.  In fact, it’s very easy for a sober driver to fail a WAT test.  For example, if there is inclement weather, the road can be slippery, causing a suspected impaired driver to wobble or be unable to make the heel-to-toe turn perfectly.  A DWI defense lawyer can examine the facts of your case to determine the cause of a failed WAT test.

Can Standardized Field Sobriety Tests Be Challenged in Court?

Absolutely!  Field sobriety tests can always be challenged in court – and should be challenged to fight your DWI charge.  These tests are notorious for being subject to outside influences. Drivers suspected of driving while intoxicated may face environmental factors that could possibly sway the results of any SFST.

To illustrate, the driver asked to walk a straight line might have a physical disability that causes them to walk with a limp or sway.  Another driver might have an eye condition that could alter the results of an HGN pin test.  Drivers only get one chance to complete these tests – there’s no practice or room for human error.  External factors could also impact the outcome of a field sobriety test, resulting in a false result.

Speak to an experienced DWI defense attorney about the details of the stop and test to discuss potential defenses to your DWI charge.

Contact a Texas DWI Defense Attorney Today

If you have been charged with DWI in Texas, contact the experienced legal team at the Westbrook Law Firm today.  We’re ready to advocate for your rights and freedom.  Do not hesitate to give us a call at 281-888-5581 and schedule a consultation.

The Westbrook Law Firm has 20 years of experience in Criminal Defense.  We want to use our expertise and dedication to help you during this trying time.  Choosing our firm means that you are getting the best team behind you.  We are invested in getting you the best available results – with a focus on dismissal or acquittal.

You need an advocate by your side until your case is resolved.  Do not delay.  Contact the Westbrook Law Firm today.