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How accurate are field sobriety tests?

On Behalf of | Mar 31, 2023 | Firm News |

Officers will often administer field sobriety tests if they suspect the driver is under the influence of drugs or alcohol. Different standardized field sobriety tests are used, depending on the details of the situation. While the results are used as probable cause for arrest, some question the validity of these tests.

High rate of error

More than 50 years ago, The National High Traffic Safety Administration (NHTSA) looked at data from tests that law enforcement used to gauge drivers’ ability to operate vehicles and their blood alcohol content. It found that officers were correct 53% of the time. It also found that there were inconsistencies in how officers conducted the tests.

The most accurate were:

  • One-leg stand
  • Walk and turn
  • horizontal gaze nystagmus test

Because of their accuracy, they are the most commonly used by officers in 2023. Still, the error rate for these tests is 23% to 35%. Used together, the rate of error drops to 18%. This more accurate lower percentage is still not close to acceptable. Moreover, scientists often do not support the science of these tests as proper methods to determine BAC; instead, they determine if the driver has good balance and can follow directions. Finally, BAC affects people differently, and higher blood alcohol does not necessarily indicate whether the driver can safely operate a vehicle.

There are still discrepancies

All this time later, field tests are still used, and they are still not accurate. Anyone charged with DUI should discuss the case with a criminal defense attorney who has extensive experience handling DUI cases. They can identify holes in the prosecution and ensure that all their client’s rights are protected to the full extent of the law.