Standardized Field Sobriety Tests, Part 3: The One-Leg Stand

 Posted on December 00, 0000 in DUI

Over the last couple of weeks, posts on this blog have talked a little about the battery of standardized field sobriety tests (SFSTs) recognized by the National Highway Traffic Safety Administration. These three tests are commonly used by police officers during traffic stops to help determine whether a driver is impaired by alcohol or drugs. If you have been arrested on drunk driving charges, you should seek help from a skilled defense attorney immediately.

Two Types, Three Tests

There are three tests that comprise the SFSTs: the horizontal gaze nystagmus, the walk-and-turn, and the one-leg stand. The first test—the horizontal gaze nystagmus—is an observation of involuntary eye movements while the subject follows a pen or flashlight with his or her eyes. The other two tests are both considered "divided attention" tests, because they test the subject’s ability to hear and follow instructions while performing simple tasks. The rationale behind these tests is that a sober person, for the most part, would have little trouble completing them, while an impaired person is much more likely to struggle.

Test 3: The One-Leg Stand

As with the walk-and-turn test, the one-leg stand test is also broken down into two phases: instruction and performance. During the instruction stage, the officer will explain to the subject what he or she is expected to do and will demonstrate the proper procedure. The officer will confirm the subject understands before moving on to the performance phase.

During the performance stage, the subject must raise one foot parallel to and about six inches off the ground. With hands remaining at the sides, the subject must look at his or her raised foot and count slowly—"one thousand one, one thousand two, etc."—until told to stop by the officer. Most tests last for about 30 seconds.

While the subject is counting, the officer will be looking for indicators of possible impairment, including:

• Swaying from side to side;
• Using the arms to maintain balance;
• Hopping to regain balance; and
• Putting the foot down.

If the subject demonstrates two or more of these indicators, the likelihood for impairment is high.

Reliability Factors

According to the NHTSA, approximately 65 percent of people who "fail" the one-leg stand test are later determined to have a blood-alcohol content (BAC) above the legal limit. This means that the test gives a false positive about one time in three. Age, physical condition, and middle-ear problems could all impact a subject’s ability to perform the one-leg stand, even while not impaired.

Law enforcement officials and prosecutors say that such tests are not meant to be taken on their own but as part of the three-test battery. The cumulative results, officials maintain, are much more convincing.

Call Us Today

If you or a loved one has been arrested on charges of driving under the influence, contact an experienced Kane County DUI defense attorney. We are prepared to help you challenges the results of standardized field sobriety tests, and we will work hard to protect your rights. Call 847-488-0889 for a free consultation at The The Law Office of Brian J. Mirandola today.

Sources:

https://ntl.bts.gov/DOCS/deskbk.html#AADID

http://duijusticelink.aaa.com/issues/detection/standard-field-sobriety-test-sfst-and-admissibility/