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Contesting the Results of Field Sobriety Tests in Las Vegas


Field sobriety tests are often used as an attempt to find probable cause for a DUI arrest in Las Vegas. The National Highway Traffic Safety Administration (NHTSA) has standardized and approved three field sobriety tests, but even those are not always reliable determinants of intoxication. The accuracy of these types of tests have been challenged over and over. The first thing that you can challenge is the accuracy percentages, for example, the One Leg Stand starts off with only a 65% reliability of predicting a BAC to be .10% or above. There is much room for error in this test and many outside factors that can affect a person's performance. The Walk and Turn test only has a 68% reliability when it comes to predicting a BAC to be .10% or greater.

Both of these tests can be greatly influenced by outside factors, including:

  • Physical disabilities
  • Types of shoes being worn
  • Levelness of the ground
  • Type of surface
  • Being overweight
  • Surrounding traffic

When it comes to the Horizontal Gaze Nystagmus test, the percentage of reliability is slightly higher, at 77%, but there are still defenses to be made. Having traffic lights in your eyes, glaucoma, contact lense irritation and error from the officer are all defenses against the results. The administration of the tests by the arresting officer is one of the main defenses for all three tests. If they do not explain the tests accurately or use judgment that is not reasonable, the results may not be valid or reliable as evidence.

For help challenging the results of field sobriety tests, team up with a Las Vegas DUI attorney. Contact my firm, the Law Office of Chip Siegel, Esq., for the aggressive and experienced DUI defense that you need. Start by filling out a case evaluation form now!