An officer who suspects a motorist of DUI / DWI usually conducts a field sobriety test to gather evidence for a drinking and driving court case. The one-leg stand test is one of three standardized field sobriety tests recognized by the National Highway Transportation Safety Administration (NHTSA). An experienced California drunk driving criminal defense attorney is skilled at challenging the results of the one-leg stand test and other field sobriety tests.
During the one-leg stand test, the officer will direct the driver to stand with feet together and arms down while the officer delivers the test instructions. The officer will tell the driver to raise one leg about six inches, with the foot parallel to the ground. The driver will be told to look at his or her foot while counting “one thousand one, one thousand two…” until told to stop. The driver must stand on one leg for 30 seconds.
The one-leg stand test, like other field sobriety exercises, is a divided-attention test by forcing a driver to concentrate on two tasks at once, it’s designed to evaluate mental and physical impairment. Prosecutors will argue that any discrepancy between the way the officer explained and demonstrated the tests, and the way the driver performed the tests is evidence of mental or physical impairment.
Specifically, the officer is looking for four signs of impairment – swaying while balancing, using the arms to balance, hopping on one foot, and putting his or her foot down three or more time during the test. If the officer sees two or more of these signs, he or she will conclude that the driver has a blood alcohol content (BAC) of .10 or greater, and the driver will be arrested for DUI / DWI.
However, experts conclude that when it comes to alcohol impairment, mental impairment always comes before physical impairment. If no mental impairment can be proven, then any physical impairment must be attributed to factors other than alcohol. In order to prove a charge of drunk driving, a prosecutor must present evidence of both mental and physical impairment, and an experienced DUI / DWI attorney can attribute all four signs of drunk driving indicated in the one-leg stand test to physical impairment.
Think about it – many people have trouble standing on one leg for 30 seconds, whether or not they’ve had a few drinks. The one-leg stand test is especially challenging for people with back or leg injuries, individuals with inner-ear disorders or other balance problems, people over 65, and those who are overweight. Uneven ground or shoes with heels higher than two inches can add to the challenge.
Remember, the results of a field sobriety test are open to interpretation. A California criminal defense lawyer skilled in defending drunk driving cases can challenge an officer’s evaluation and demonstrate that a driver’s performance in the one-leg stand test and other field sobriety exercises could just as easily show that the driver was not impaired.