Arrest and Field Tests

FIELD SOBRIETY TESTING

The field testing given to citizens suspected of driving under the influence (DWI) is usually a combination of standardized field tests promulgated by the National Highway Traffic Safety Administration (NHTSA), and those inherited from other police officers. An officer becomes certified to give the standardized tests by taking a 40-hour course. Ostensibly, they graduate from the course knowing the right way to offer and grade these field sobriety tests. With regard to the Horizontal Gaze Nystagmus test (the pen test), an officer is required to practice in the field a certain number of times before being certified.

STANDARDIZED FIELD TESTS

The field sobriety tests you are likely to be offered when stopped by the police on suspicion of DWI are the walk and turn, the one leg stand, and the Horizontal Gaze Nystagmus test (pen test). These are considered the "standardized" tests. On occasion, an officer will also give you the head tilt test, the finger to thumb test, the nose touch test, or ask you to recite the alphabet. Most of the time these procedures will be video taped.

TESTING ON PHYSICAL AND MENTAL ABILITY

What many citizens don't know is that with regard to the one leg stand and walk and turn tests, the officer is judging them on both their physical dexterity and their mental acuity. You might be able to juggle chain saws and still "fail" the evaluation if the officer believes you didn't sufficiently follow their instructions. The slightest variation in testing can bring you a black mark. For example, if a person stands solidly on one leg but fails to look at their pointed toe, the officer will mark them down for not following instructions.

HORIZONTAL GAZE NYSTAGMUS (HGN)

The Horizontal Gaze Nystagmus test, or pen test, is designed to determine whether a person's eyes jerk involuntarily as a result of ingesting alcohol or other intoxicating substance. The officer places a stylus - usually a penlight - 15 inches from the eyes of the suspect, and waives it back and forth in front of the suspect in three repeated intervals. If the officer sees jerking they interpret its significance by determining where the jerking first occurs.

There are numerous problems with the pen test, including the fact that it's an assessment for a medical condition that is dependent on interpretation by a person with no medical training. However, the most troubling thing about the test is that it is done in secret. Although the other tests are video taped, which enable the jury and other witnesses in a drunk driving defense case to come to their own conclusions about how the defendant did, only the officer views the pen test. No medical expert can independently verify the officer's interpretation.

"STANDARDIZED" DOESN'T MEAN SCIENTIFIC

Prosecutors attempt to portray the "standardized" DUI field tests as scientific since they are accepted by the NHTSA. In reality, there is nothing scientific about them and they achieved their status simply because they were considered the most reliable indicators of intoxication among all the tests considered. However, "reliable" is clearly relative. The NHTSA confesses that the one leg stand is only a correct indicator of intoxication 65% of the time and the walk and turn only achieves a 68% grade in making that determination. Further, even this low percentage of reliability makes the assumption that the tests were given in the proper "standardized" manner.

If you have been charged with driving drunk based on field sobriety testing, contact our law office online, or call us at 713-222-9141 to discuss your DUI case with an experienced criminal defense attorney.