If you have been polite and accommodating and waived your Constitutional protections and agreed to do field sobriety testing for a law enforcement officer who has stopped you I am sure he or she had you do the "pen test" or "eye test"; what is technically called the Horizontal Gaze Nystagmus (HGN) test. DUI trained law enforcement officers will tell you the HGN test is one of the standardized field sobriety tests they use to determine if you are driving while intoxicated. What they won't tell you is that they have about 8 hours of training in Horizontal Gaze Nystagmus training and that every minute of their training is biased toward what will prove the influence of alcohol or drugs. Not a single minute of their training concerns the truth that many people have a natural 'jerk' to their eye movement or that multiple environmental stimulus, like the lights of passing vehicles, will materially change testing results. Why won't they tell you these things? Because they either don't know about them in which case they are totally UNQUALIFIED to run such a test or more concerning because they COULD CARE LESS. So what is HGN? The test in essence is a measurement of the movement of the eyes. Nystagmus refers to the involuntary jerking of the eyes back and forth. Horizontal refers to the officer moving a pen or other object horizontally across your field of vision. DUI officers claim that they are looking for three clues in each eye during this HGN test. The first part of the test is to determine if a DUI suspect's eyes are able to pursue smoothly - is there jerking in the movement of the eyes. The next part of the test is to determine if there is nystagmus at maximum deviation - when the pen is held with your eyes as far out as they can go, is there nystgamus. Finally, the officers are looking to see when the nystagmus occurs as they move the pen across your field of vision. They are to mark off if they see nystagmus prior to a 45 degree angle. Each eye is suppose to be checked twice for each of the 3 clues. The total maximum number of clues for the test is 6. What the officers don't normally tell you is that there are over 40 types of nystagmus that can naturally occur in an individual. They also don't tell you that they can't differentiate these other 40+ types of nystagmus and they have not heard of most of the other types of nystagmus. Most of them are CLUELESS that these deviations exist because they are not trained to perform unbiased testing but rather they are trained to perform the testing solely to prosecute for the offense of DUI!
According to the federal standards for the HGN, the officers are suppose to use objective criteria for administering the test and scoring the test. More often than not, however, the officers simply just report that the DWI suspect has 6 of a possible 6 clues on the test.
As Coweta Circuit [Counties of: Coweta, Carroll, Meriwether, Troup and Heard] and Griffin Circuit [Counties of Fayette, Spalding, Upson and Pike] lawyers, we have seen hundreds of videos where the officers perform the HGN. We have yet to see an officer ask a client if he or she has naturally occurring nystagmus.
If you have been arrested for DUI, ask your lawyer how many clues the cop says you had on the HGN. The answer you will get is probably going to be 6 of 6 and you will not have been asked a single question about whether you have a natural HGN. the last trial I had the officer took the test with my client being required to stare into the headlights of the patrol car; about as complete a violation of the HGN test as can occur!
