When a police officer stops a driver on suspicion of driving under the influence of either drugs or alcohol, the officer is authorized to administer various field sobriety tests to determine whether or not to make an arrest. Once a driver is arrested, the police may facilitate further chemical testing. There are three main standardized field sobriety tests that the police can use in Illinois; the horizontal gaze nystagmus (HGN) test, one-legged stand, and walk-and-turn.
The Horizontal Gaze Nystagmus Test
This is generally considered to be the most accurate of the three standardized tests. The test involves the observance of the involuntary jerkiness of the eyeball. The more impaired a driver is, the more pronounced the jerkiness is as the test is conducted, because alcohol or drug consumption can interfere with the brain’s ability to control the eye muscles. However, there are conditions, such as a lazy eye, that may interfere with the test and cause the test to yield inaccurate results.
There is a proper way to administer a HGN test, and the standard for proper administration is set by the National Highway Traffic Safety Administration (NHTSA). If the test is not administered properly according to standards set forth by the NHTSA, or if the driver has a condition that may interfere with the test, the driver may be able to successfully challenge any results from this test in court.
The common way that police officer administer this test is by holding an object like a pen in front of the driver’s eyes, and moving it side to side. The officer then holds the object further back, about 12 inches from the driver’s eyes, and moves the pen side to side once more. The driver keeps his or her head still, and follows the object with his or her eyes. There are indicators that the police officer is supposed to look for that suggests that the driver is impaired. There are three indicators that the officer looks for and grades one point for each eye, for a total of six points. If the driver scores a 4 or more, the driver has failed the test.
One-Legged Stand Test
For this test, the police officer administering the test should both explain and show the driver how to complete the test. To perform the test, the driver has to put his arms by his sides while standing still with his feet together, and then lift one leg about 6 inches off the ground. The driver has to hold this position while counting upwards of 1,000, for about 30 seconds.
The police officer then observes the driver for the signs of impairment; such as swaying, using the arms for balance, hopping on the foot on the ground, or resting the raised foot more than three times during the 30-second count.
Walk and Turn Test
Like with the one legged stand test, the police officer should both explain and demonstrate the proper way to complete the test. The test basically requires the driver to walk in a straight line by placing the heel of one foot right before the toes of the other, with his arms by his sides, and then turn and walk back to the officer in the same way. The driver must take 9 steps in each direction. The driver must also keep his eyes on his feet during the test, and also count each step out loud. During the test, the police officer looks for the following signs that may indicate impairment.
- Starts or stops the test before instructed to do so
- Unable to balance
- Failure to touch heel-to-toe
- Stepping off of the line
- Using arms to balance
- Using the incorrect number of steps
Contact a Chicago DUI Defense Lawyer
If you are arrested for a DUI after taking and failing one of the field sobriety test described above, there may be ways to challenge the way the test was given, and the subsequent results. Contact Chicago DUI attorney Steven Goldman for a consultation on your case.