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Charged with DWI?
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San Antonio Field Sobriety Test Attorneys

Challenging the Validity of Field Sobriety Tests

DWI arrests are often based on field sobriety tests. Police officers who suspect impaired drivers often use these tests to determine probable cause of intoxication and to establish the grounds for an arrest. The officer administering the test will usually provide testimony regarding the testing that can additionally be used in court to assist the prosecutor’s contention that the driver was driving while impaired.

If you have taken a field sobriety test that ended in a “failure” to pass, it does not provide solid evidence that can or should lead to a conviction. At Smith & Vinson Law Firm, we deal with these tests on a regular basis. We do not take them at face value. Our San Antonio DWI lawyers can and will exhaustively investigate and assess your particular case to get to the truth. After doing so, we can determine how best to defend you in court by challenging such tests and other evidence that may be used against you. Throughout the duration of your DWI case, we will fight relentlessly for your constitutional rights.

Call Smith & Vinson Law Firm for a free case evaluation at (210) 960-9557 today.

What Are Field Sobriety Tests?

San Antonio law enforcement generally use three standardized field sobriety tests when pulling drivers over for suspected DWI. These tests seek to uncover both physical and mental impairment caused by drugs or alcohol.

These tests include:

  • Walking and turning
  • Standing on one leg
  • Horizontal gaze nystagmus (checking for involuntary eye jerking when looking to the side)

How We Challenge Field Sobriety Tests

These tests examine one’s coordination, balance, and ability to follow directions. Standards have been set on which police officers determine results. These tests are not always reliable, however, and they can be further skewed by improper administration. That is why our San Antonio DWI attorneys believe that it is vital to challenge their results whenever possible.

We may challenge field sobriety tests by questioning:

  • How the testing area was lit
  • Whether the ground was flat, pitted, or otherwise uneven
  • What type of shoes the driver wore
  • How the instructions were relayed to the driver
  • Whether or not the officer properly evaluated what he saw
  • Whether or not the driver had a physical condition that would affect his ability to perform the tests
  • Whether or not the officer received proper training on how to administer such tests

Learn more about how Smith & Vinson Law Firm can challenge your DWI case. Contact us at (210) 960-9557 today.

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  • Professional representation at its best!

    “I am grateful for the representation both men have provided me and without hesitation, I would speak volumes of their service. Thank you so much!”


  • Second to NONE

    “I would love to add my thanks and heart felt appreciation for the help that your law firm provided me. Before I met you guys my situation looked very bleak and quite honestly your dedication to my case really carried over this past year and the reward was not only one felony dismissal but two. Thank you from the Ramirez family, I will always be great full and you guys have earned a spot in my family. For anyone reading, this firm is second to NONE, they know what there talking about and do exactly what they promise to do. Very professional, on time and and educate you along the whole process. I had alot to lose and you guys gave it all back to me and finally represented what true Justice is here in America. God bless you both and God bless your firm”

    Manuel R.

  • Exceptionally versed in the intricacies of Texas criminal law

    “Having never been exposed to the criminal system, hiring an attorney was daunting task. Attorney Brad Vinson was informative, professional yet sympathetic with his approach to my case. Mr. Vinson was open to opinion and ensured that all legal avenues were considered and addressed before presenting a course of action. Ultiamtely, Mr. Vinson was able to negotiate a reasonable settlement dispite many hoops and hurdles presented by the prosecuting county. I would highly recommend Smith and Vinson for representation in a criminal matter.”


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    “He is well versed in evidence and criminal law nuances, skills which allow him to level the playing field for his clients and make certain they get a fair chance at justice.”


  • He's a real lawyer!

    “A civil issue arose in Austin with a family member. We sought the advice of a well named Austin attorney. This unnamed attorney provided egregious legal advice. In court, a lifetime civil injunction was ruled by the judge on this non-criminal civil issue. Once learning of this judgement we immediately started looking for another attorney and found Brad Vinson, with Smith and Vinson. Simply put, Brad had this entire debacle reversed and a new judgement set for what is customarily ruled in similar cases. It didn't take long either. I only wish we had called Brad first. He's a real lawyer!”


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