Since police officers in Texas and across the country use field sobriety tests to establish probable cause in DWI arrests, many people believe that these tests are quite accurate. However, a number of researchers would argue that these tests possess flaws in determining impairment.
How Were These Tests Created?
During the 1970s, the National Highway Traffic Safety Administration (NHTSA) assigned the Southern California Research Institute (SCRI) the task of assessing dozens of field sobriety tests that were in use to determine which were the most accurate. After evaluating the data, the institute recommended that the one-leg stand, walk-and-turn, and horizontal gaze nystagmus tests be used to test for impairment.
Numbers Behind the Tests
However, the NHTSA knew that the officer’s error rate for determining BAC using these tests was only 47% according to the study. Again, the administration hired the SCRI to standardize the protocol of these tests in order to lower the rate of error. They discovered that standardizing the tests gave the one-leg stand a 65% accuracy rate, the walk-and-turn a 68% accuracy rate, and the horizontal gaze nystagmus test a 77% accuracy rate. When all three were used together, they were correct only 82% of the time.
Challenging Field Sobriety Tests
Scientists will argue that the accuracy rates of field sobriety tests do not support their reliability when determining intoxication. Overall, these tests are not a scientifically proven method to determine probable cause and arrest someone on suspicion of DWI.
At Peveto Law, our Plano criminal defense attorney knows expert witnesses who study field sobriety tests who understand their flaws. Any individual arrested for drunk driving due to a failed field sobriety test score is encouraged to challenge the results in order to fight their criminal charge.
Contact us and request a free consultation today.