Field Sobriety Tests

When a person is stopped for alleged driving while intoxicated (DWI) offense in Texas, law enforcement will typically ask the alleged offender to perform a number of field sobriety tests. It is important to understand that while a person is deemed to have consented to submit to a breath test as a condition of being granted a driver’s license in Texas, there is no requirement that a person submits to field sobriety tests.

For court purposes, field sobriety tests are generally divided into the battery of three tests that are considered standardized field sobriety tests that may be permissible in court and other field sobriety tests that are considered non-standardized and may not be allowed in court. Unlike breath tests that impartially measure the alcohol content in a person’s system, field sobriety tests are far more subjective and can lead to police officers drawing incorrect conclusions that may have been based on other factors besides alcohol consumption.

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Field Sobriety Tests Defense Lawyer in Denton, Frisco, Lewisville, Flower Mound, TX

If you were arrested for DWI anywhere in Denton County like Denton, Lewisville, Flower Mound, Little Elm, or another nearby community in Texas after submitting to field sobriety testing, you are going to need an attorney to help you fight your case in court. Do not wait to contact The Law Offices of Richard C. McConathy. 

Our firm will be able to examine every aspect of your arrest and determine the strongest possible defenses against the criminal charges. You can call (940) 222-8004 or contact us online to have us look over every detail of your case when we talk to you during a free consultation.

Standardized Field Sobriety Tests in Denton County, Texas

The National Highway Traffic Safety Administration (NHTSA) and the International Association of Chiefs of Police (IACP) developed Standardized Field Sobriety Testing (SFST) training curriculum in the early 1980s. Standardized field sobriety tests include the following three tests:

  • Horizontal Gaze Nystagmus (HGN) — If an individual is under the influence of certain drugs or alcohol, their eye could do an involuntary jerking movement known as nystagmus. The higher the degree of impairment, the sooner the nystagmus will be observable. The horizontal gaze nystagmus (HGN) is an involuntary jerking of the eyes, as they gaze toward the side. Vertical Gaze Nystagmus (VGN) is an involuntary jerking of the eyes (up and down) which occurs when the eyes gaze upward at a maximum elevation a police officer typically holds an object 12 to 15 inches from the driver’s eyes and will slowly move it from side to side. A driver is asked to follow the object with their eyes and if they have issues tracking the object, it is considered a sign of impairment. Vestibular Nystagmus is caused by movement or action to the vestibular system that can occur when an individual has spun around and the fluid in the inner ear is disturbed or there is a change in the fluid (temperature, foreign substance, etc.). Neural Nystagmus is caused by some disturbance to the neural system. In this course, we will only be concerned with gaze-evoked neural nystagmus. Pathological Nystagmus is caused by the presence of specific pathological disorders, which include brain tumors, other brain damage, or some diseases of the inner ear. NHSTA states that HGN tests have a 78 percent accuracy although that is not always the case. Some of the factors that could skew HGN tests results include loud horns, heavy traffic, or inclement weather.
  • One-Leg Stand (OLS)  — The one-leg stand is one of the most common kinds of field sobriety tests conducted. The police officer asks the driver to stand on one foot with the other foot about six inches off the ground. The driver is then instructed to count aloud for 30 seconds in the thousands. A driver who has any issues with balance, hopping, or even counting could be deemed intoxicated. Numerous factors can impair a person’s ability to perform this test, however, including driver fatigue, physical ability, or simple age.
  • Walk-and-Turn (WAT) — The walk-and-turn test is used to determine if a person’s physical faculties are impaired. A police officer asks the driver to take nine heel-to-toe steps along a straight line. When the person reaches the end of the line, the driver turns on one foot and takes another nine head-to-toe steps back. Sober individuals may fail these tests because of factors such as impaired vision, slippery roads, or bad lighting at traffic stops. The WAT is supposed to be conducted on a reasonably dry, hard, level, non-slippery surface. There should be sufficient room for subjects to complete nine heel-to-toe steps. 
 

OLS and WAT are both considered divided attention field sobriety tests. Divided attention means concentrating on more than one thing at a time, and a divided attention test requires a person to concentrate on both mental and physical tasks at the same time. 

Non-Standardized DWI Field Sobriety Tests in Denton, TX

Standardized field sobriety tests are generally considered more beneficial to prosecutors because courts will be more likely to allow the results of those tests as evidence in DWI cases. If police officers use other non-standardized tests, then there will be no guarantees that the test results can be used in a court case.

Some police officers will still use other non-standardized tests for field sobriety testing purposes, and individuals who agree to these tests should be aware of the admissibility issues. Common kinds of non-standardized field sobriety tests include: 

  • Finger-to-Nose Test — Police officers use finger-to-nose tests to measure self-awareness. A person is asked to close their eyes, tilt their head back, and touch their nose with their index finger. An officer asks the driver to perform the test three times with each hand. Police officers usually look for signs of impairment such as swaying, stumbling, or inability to finish the test.
  • Romberg Balance Test — The Romberg Balance Test involves a police officer asking the driver to stand with their feet together, head tilted back, and eyes closed. The driver is asked to call out “stop” once the driver believes 30 seconds have passed. Police will be looking for signs of intoxication such as body tremors, swaying, and inability to stand straight for signs of intoxication.
  • ABC Test — A person could be asked to recite or write the alphabet. In some cases, officers could ask for the alphabet to be recited backward. Law enforcement will usually be looking for signs of struggle such as slurred speech, missed letters, and also to see if the driver’s breath smells like alcohol.
  • Backward Numbers Test — A backward numbers test involves a police officer asking a person to count backward from a certain number. Law enforcement will typically be using such tests to look for signs of confusion, speech errors, slurred speech, or other signs of impairment.
  • Finger Count Test — The finger-count test is another divided attention test that measures a person’s ability to follow instructions and perform a physical task. The individual is asked to extend one arm with the palm facing forward and use the top of their thumb to touch their remaining fingers while counting each time their fingers and thumb connect. This is performed three times. Officers will look for such signs of intoxication as starting the test too soon, problems following directions, problems counting, problems touching each finger correctly and in the right order, problems performing the correct number of sets, or stopping the test early.
  • Hand Pat Test — When a person is asked to perform the hand pat test, they will be asked to extend one arm out with the palm facing up and out and the other hand is placed on top, with the palm facing down. They then rotate their top hand 180 degrees to pat the bottom hand with the back of the other hand and count “one” before rotating it again so your top palm touches the bottom palm while they count “two.” An officer asks them to keep counting until asked to stop. Police look for signs of intoxication such as problems following directions, starting too soon, failing to count as instructed, and failing to pat your hands correctly.
 

Texas Field Sobriety Testing Resources

DWI Detection and Standardized Field Sobriety Testing Refresher – NHTSA — View this October 2015 manual from NHTSA addressing field sobriety testing. The manual includes an overview of the course, including the intended audience, the purpose of the training, course content, and length of the training as well as instructor-led course materials such as the instructor’s lesson plans guide, visual aids, and participant manual. There is also an SFST Proficiency Form, Post Course Exam, and Remedial Exam.

Field Sobriety Test Review | Texas District & County Attorneys Association (TDCAA) — View this field sobriety test review from the TDCAA, a non-profit organization dedicated to serving Texas prosecutors and their staff by producing comprehensive continuing legal education courses for prosecutors, their investigators, and key personnel, providing technical assistance to the prosecution community and related criminal justice agencies, and serving as a liaison between the prosecutor and other organizations in the day to day administration of criminal justice. Learn more about the categories of Nystagmus and things to know about HGN tests. You can also find a comparison of SFST accuracies between 1981 and 1998, which found improvement in the accuracy rates for all three standardized tests and a difference of 81 percent combined accuracy in 1981 as opposed to 91 percent accuracy in 1998.

Find A Denton County Defense Attorney for Field Sobriety Tests | Law Offices of Richard C. McConathy

Did you submit to field sobriety tests when you were arrested for DWI? Contact the Law Offices of Richard C. McConathy today for a consultation about your alleged offense in Denton, Frisco, Lewisville, Flower Mound, and surrounding areas of Denton County, Texas.

The Law Offices of Richard C. McConathy regularly defend clients against DWI charges in communities all over North Texas. You can have us review your case and talk about what options you have when you call (940) 222-8004 or contact us online to receive a free consultation.