Ever since the 1970’s, law enforcement officers have been administering
the three “standardized”
field sobriety tests (FSTs)—the walk-and-turn, one-leg stand, and horizontal gaze nystagmus—to
determine whether a driver has operated their vehicle while intoxicated.
A driver’s performance on these tests is meant to indicate whether
the individual has a BAC of .08% or more, acting as a basis of an officer’s
probable cause for a
Alas, the reliability of these test results is often questioned.
How Reliable Are These Tests?
The National Highway Traffic Safety Administration (NHTSA) performed a
number of studies where officers gave FSTs to people with known BACs.
The main goal was to figure out how well officers could identify a person
with a BAC of .1% or higher
According to the results of these tests, studies showed officers could
correctly identify these drunk drivers:
- 80% of the time using multiple FSTs
- 77% of the time using the horizontal gaze nystagmus test only
- 68% of the time using walk-and-turn test only
- 65% of the time using the one-leg stand only
Scientists will contend that the accuracy of these tests does not support
the reliability of standardized FSTs. For example, when these tests are
correct, they only indicate BAC level, not a person’s ability to
operate a vehicle.
Challenging Field Sobriety Tests
Criminal defense attorneys and expert witnesses who study FSTs understand
their flaws. Any individual arrested for DUI on the basis of an FST score
is encouraged to challenge these results in an effort to either get your
entire case dismissed or your charges reduced significantly.
Recently arrested for a DUI in Ventura County, CA?
Contact our Ventura DUI attorney at
The Law Offices of Robert F. Sommers and request a free consultation today.