Secrets of the One Leg Stand

In my previous post, I discussed the benefits of refusing to submit to field sobriety testing if a driver has been stopped for suspicion of DWI/DUI.  Unfortunately for them, many drivers still submit to the tests.  Of the three standardized field sobriety tests, the One Leg Stand (OLS) is the last test that is administered in the battery and the most unreliable.  How do we know this?  Because it is right there in black and white in the training materials from the National Highway Traffic Safety Administration (NHTSA).

NHTSA informs its trainees that based upon laboratory research, when the OLS is administered in a standardized manner, it is 65% accurate in detecting blood alcohol levels above .10. Think about that for a minute.  If you were told that the plane you were about to board had highly reliable landing gear that worked 65% of the time, would you board the plane?  A test that is 65% accurate in detecting blood alcohol levels above .10 is chock full of reasonable doubt.  It should come as no surprise that officers have a number of tricks up their sleeves when asked to perform the test in court.

To perform the OLS, the driver is instructed to raise one leg with the foot approximately six inches off the ground.  The driver is instructed to keep the raised foot parallel to the ground.  The driver is instructed to keep both legs straight and arms at the driver’s side.  While holding this position, the driver is instructed to count out loud, “one-thousand, two-thousand,” until the driver reaches 30 seconds, all the while keeping the driver’s legs straight, arms at the side, and looking at the driver’s raised foot.

Officers are looking for 4 clues:  swaying, using arms for balance, hopping, or putting the foot down.  “Swaying” is defined in the training as a “side-to-side” or “back-and-forth” motion.  Go ahead and try the OLS and see if you can remain perfectly still for 30 seconds without any motion that is back-and-forth or side-to-side.  Unless you have amazing balance, chances are you will fail this test.  Now imagine performing this test alongside a highway with traffic whizzing by at high speeds and an officer shining a light in your face, and you can begin to understand just how the deck is stacked against drivers.

I have heard many stories from colleagues who have asked officers to perform the field sobriety tests in court while on trial. I was amused to hear one tale of a prominent DWI officer who fell over while trying to do the OLS.  After all, officers have to show the judge or jury just how easy it is for sober people to do these tests.  Naturally, they employ a couple of tricks to ensure they do not fall over in the middle of the trial.

One such trick is the “thumb hook,” where the officer performing the test will hook the thumb of the opposite hand into the officer’s pants pocket.  For example, if the officer raises the right foot for the OLS, then the officer will hook the left thumb into the left pants pocket.  This provides a centering of the officer’s balance.

This is usually a subtle move…and it is technically compliant with the instructions since NHTSA only instructs that the subject’s arms have to remain at the side.  Try doing the OLS now and see how the thumb hook makes a difference.  Another trick is for officers to slightly bend the standing leg, which makes it easier to hold the officer’s position.

These tricks are easy to detect at trial but are often overlooked since the focus is on the officer’s attempt to remain standing for 30 seconds.  Of course, the bigger question is if this test is as reliable as NHTSA wants us to believe then why do officers have to cheat to perform it in court?

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