One of the most important pieces of evidence the prosecution will use against you is your field sobriety test results. The government has to prove that you were driving while intoxicated without a reasonable doubt, so the sobriety test works as a concrete form of evidence to prove this.
Fortunately for you, the test isn’t always so concrete.
Due to the complicated nature of a DWI charge, the officer administering the sobriety test has to follow strict, standardized procedure. If the procedure used isn’t one of the standardized field tests authorized by the National Highway Traffic Safety Administration (NHTSA), then the sobriety test is not sufficient evidence and will not hold up in court. The three standardized sobriety tests are:
- the one leg stand test
- the walk and turn test
- the horizontal gaze nystagmus test (HGM)
Any non-standardized test administered by the officer such as the finger to nose test or saying the alphabet are not valid methods of determining intoxication. In the case that the officer did not administer any of the three standardized field sobriety tests, call us immediately. Your DWI charge has a slim chance of holding up in court.
Even if you are given a standardized test, the circumstances of the test can be challenged in defense of your DWI charge. Senior citizens, people who are overweight, and people with disabilities or injuries should not be given a one of these tests. Environmental conditions can alter the results of the test too. If the ground is wet or uneven, you can fail the test without having consumed a single drink. During an HGM test, the officer must be able to clearly see your eyes. If you’re given the test at night and the officer doesn’t use a flashlight, this can definitely be challenged in court.
Police officers must also be certified to perform the sobriety tests, especially the HGM. If we find that the officer was not certified, we may have your case dismissed altogether.
The usefulness of these tests in determining intoxication are questionable at best considering a sober person can fail under many circumstances. In fact, none of the tests are reliably accurate. The NHTSA found that the horizontal gaze nystagmus is 77% accurate, the walk and turn is 68% accurate, and the one-leg test is only 65% accurate in determining intoxication. Breath tests too aren’t completely reliable in that they have a margin of error of 12.5%. Considering the prosecution has to prove you were driving while intoxicated beyond a reasonable doubt, these tests alone are not enough to convict you.
Winning your DWI case is not impossible. Field sobriety tests are subject to a variety of procedural issues that can work in your favor, nor are they particularly accurate. If you’ve been charged with a DWI, contact the Law Offices of Jef Henninger, Esq. immediately. We have an aggressive team of defense lawyers who know how to fight and beat a DWI charge.