The three most common field sobriety tests are the Horizontal Gaze Nystagmus (HGN), 9 Step Walk and Turn, and the One Leg Stand. Only those three tests have been approved by the National Highway Traffic Safety Administration for use in DUI investigation. However, Virginia law enforcement officers use a variety of other field sobriety tests when they are investigating DUIs. The other tests that Virginia officers use are the Alphabet Test, Finger to Nose Test, Counting Backward Test, and Finger Dexterity Test.
Horizontal Gaze Nystagmus (HGN)
When administering the HGN, the officer should ask you to stand facing away from his flashing lights. He will hold his finger or a pen or pencil in front of your eyes and ask you to follow it with your eyes. He will be looking to see whether your eyes are jerking involuntarily. Officers are trained that this test is the most reliable, but there is significant scientific research showing the HGN is not reliable when determining whether someone is intoxicated.
9 Step Walk and Turn
When administering this test, the officer will first demonstrate himself performing part of the test. The officer will ask you to stand with one foot in front of the other, heel to toe. Then he will walk several steps heel to toe, pivot, and walk back toward you heel to toe. He will ask you to count 9 steps outloud in both directions. This test can be difficult because most often you will be asked to walk along an imaginary line and told that you should not use your arms for balance.
One Leg Stand
For this test, the officer will instruct you to stand on one foot. He will ask you to raise your other foot six inches off the ground and count out loud to 30. He will also tell you to keep your arms at your side and not raise them for balance.
If these tests sound like junk science, it's because they are. Officers in Virginia are generally not even allowed to testify to whether you passed or failed the tests, although they will probably tell you or the magistrate whether they believed you passed or failed. But even though these tests have never been independently researched and tested, judges in Virginia will allow officers to testify about your performance of these tests. As an exercise, try performing the tests when you haven't had anything to drink and see how you do.
How Do I Prepare for Field Sobriety Tests?
The best way to prepare for field sobriety tests is to practice saying, "No I do not want to take field sobriety tests" or “I would like to speak with an attorney before I take any field sobriety tests.”