Myth About HGN – The Eyes Do Lie!

Do The Eyes Lie? : The Myth About HGN – The Need To Videotape The Test

The Horizontal Gaze Nystagmus refers to the involuntary jerking or sudden movement of the eye that naturally occurs when the eyes gaze to the side. It is included as one of three major components of Standardized Field Sobriety Testing (SFST) developed by NHTSA to establish the low standard probable cause to arrest, nor was it intended to establish intoxication beyond the high standard of beyond a reasonable doubt, or even the lower standard of clear and convincing evidence. HGN has generated the most controversy, both from scientific and legal perspectives. .

Recently, during a DWI trial, involving a Refusal to take a Breath Test

Recently, during a DWI trial, involving a Refusal to take a Breath Test, one of Nassau County’s “Most experience breath technicians” indicated under oath that that Horizontal Gaze Nystagmus is a reliable indicator the motorist intoxication. To support this contention he quipped that his colleagues have a saying “The Eyes Don’t Lie,” in an attempt to bolster his opinion that the defendant was intoxicated. In that case, the accused displayed 4 clues out of the possible 6 clues, which the Officer testified that he had been taught, indicated that a person was intoxicated. Upon further cross examination, this Officer could not cite any authority to support this proposition. When pressed as to whether he was familiar with studies supporting his assertion, he made vague reference to the so-called ” San Diego Study” This was a study that was conducted in San Diego to determine whether the NHTSA SFST protocol could be used in helping Police Officer identifying accused individuals of being intoxicated or impaired by alcohol. To begin with the methodology employed in this study, falls far short of being scientific in any true sense of the word, nor could it pass any objective review as being valid and therefore its overall conclusions, are questionable at best.

People that displayed 4 clues were ACTUALLY were not intoxicated.

However, when one analyzes the “raw data” of this Study from which the Officer used to support his contention, it was revealed that this “very experienced” breath technician whose opinion has no doubt led to numerous convictions - Was completely wrong! In fact, an analysis of the raw data by an expert retained by the defense, established that the reliability of four clues showing that a person was intoxicated was the same as the reliability of flipping a coin. That is, astonishingly 50% of the time, People that displayed 4 clues were ACTUALLY were not intoxicated.

In fact the only study that was completely dedicated to the reliability of the HGN test, showed that this as well other research touting a even higher reliability rate were incorrect. In The Robustness of HGN (2007) a NHSTA sponsored study, an analysis of the data, gather showed, that even when administered correctly and graded correctly the HGN produced a false positive rate of 67%, moreover 68% of individuals who had four or more clues, where below .05 BAC - That Legally Sober in New York State!!! One individual who had six clues and had a BAC .019. These percentages fall Far below Reasonable Doubt. Moreover, it is the most subjective test, because there are absolutely no standards as to how much or little a jerk in the eye constitutes a clue, For example the existence of slight nystagmus is not considered by many in field to even be a clue, but yet are often considered as a clue by the Police in making an arrest. Everyone has a nystagmus to some extent, and fatigue, medication, as well as a multitude of scenarios can cause it on a legally sober individual. Readings of as low as .02 in the blood will produce nystagmus in many individuals. 

For obvious reasons, the results of the HGN testing component are significantly more reliable when conducted by scientific or medical experts under carefully controlled laboratory conditions than when conducted by layman officers in the field. HGN is an entirely subjective test as to how the administrator performs and interprets it, in terms of what constitutes a “flick” or nystagmus as being attributable to alcohol impairment rather than some other factor, or whether a nystagmus is even present. Unfortunately, law enforcement agencies currently utilize this test very seldom visually record the administration of such test.

HGN being conducted by officers, it is very often administered incorrectly...

Having seen numerous videos of the HGN being conducted by officers, it is very often administered incorrectly, which would invalidate the test. Although technological techniques exist to record eye movement, police departments do not utilize such equipment, which would permanently and empirically memorialize the actual test results to corroborate their otherwise conclusory results. Nassau had the opportunity to buy this equipment for a fraction of the cost of the cost of one day of trial for someone accused of Driving Under the Influence. Despite a Supervisor recommendation to do so, the Department rejected the opportunity to memorialize the actually results of the test. Even an inexpensive HD camcorders or even an iphone video, can accurately document the results.

The lack of Medical experience by the officers performing this test it is disturbing...

While several New York law enforcement agencies routinely employ HGN for detecting and measuring intoxication, a close examination of the technique as employed raises grave concerns. For instance, pursuant to procedures set forth by the National Highway and Transportation Safety Administration (NHTSA), officers are instructed to observe the subject and take note of the “first sign of jerking.” HGN, however, is far more than “jerking.” An officer merely looking for “jerking” may record rotary or Periodic Alternating Nystagmus (PAN), although both are undesired side effects. Whereas NHTSA administered placebos to those with natural nystagmus or who were taking prescription drugs known to produce such results, in practice officers do not take an adequate history prior to the administration of the test. Given that the “jerking” definition is taught to officers, a full medical history should be taken; given the circumstance in which the test is administered, it does not seem probable that a forthright history can be obtained. There are more than 40 different types of nystagmus other than HGN. Given that lack of Medical experience by the officers performing this test it is disturbing that they can even testify pertaining to the causes of Nystagmus at all. Contact lenses also create problems, as they can impede the smooth travelling the eye. Whereas NHTSA now recommends that they be removed, officers frequently fail to ask if they are being worn and, of course, removal under the circumstances creates difficulties that are perhaps insurmountable.

There are numerous other causes of nystagmus other than alcohol...

Perhaps the greatest impediment to the use of HGN is its unquestioned lack of specificity. HGN is not admissible to establish a precise blood alcohol content (BAC), or, in most jurisdictions, even whether the defendant was intoxicated. Additionally, there are numerous other causes of nystagmus other than alcohol, such as the role of anxiety, fatigue, and environmental conditions. A comprehensive review of HGN studies published in the Journal of Forensic Sciences questioned the validity of the HGN. The Authors noted “Limitations of HGN and its supporting literature from a behavior science perspective include: (i) Minimal evidence that is related to driving or behavioral impairment, (ii) lack of a true double-blind studies to provide an unbiased estimate of its relation to BAC, (iii) interrater reliability below accepted standards, (iv) susceptibility to medical conditions and some medications, and (v) the prevalence of potentially confounding factors present at many DWI stops, including anxiety, fatigue, and circadian rhythms.” Rubenzer S, Stevenson S, Horizontal Gaze Nystagmus: A Review of Vision Science and Application Issues, J. of Forensic Sci. 2010), In fact, the Authors of the 1981 NHSTA study reported that “the effects of fatigue or circadian rhythms on gaze nystagmus could be significant, finding that the “alcohol dose decreased the angel of onset by an additional five degrees” based upon the hour.

Caffeine, nicotine, or aspirin also lead to nystagmus almost identical to that caused by alcohol consumption

The existences of other causes of HGN, unrelated by alcohol, have not only been noted in the Scientific Community, have but have also been recognized by the courts. The Supreme Court of Kansas in State v. White, held the HGN “Nystagmus can be caused by problems in an individual’s inner ear . . . Physiological problems such as certain kinds of diseases may also result in gaze nystagmus. Influenza, streptococcus infections, vertigo, measles, syphilis, arterio-sclerosis, muscular dystrophy, multiple sclerosis, Korsakoff’s Syndrome, brain hemorrhage, epilepsy, and other psychogenic disorders all have been shown to cause nystagmus. Furthermore, conditions such as hypertension, motion sickness, sunstroke, eyestrain, eye muscle fatigue, glaucoma, and changes in atmospheric pressure may result in gaze nystagmus. The consumption of common substances such as caffeine, nicotine, or aspirin also lead to nystagmus almost identical to that caused by alcohol consumption.”

The HGN, as currently administered as a component of SFST by New York law enforcement agencies, is critically flawed in its application. The relevance of HGN to an
individual’s sobriety is predicated upon the results of testing performed by scientific or medical experts under controlled laboratory conditions – a radically different setting than testing being performed in the field by layman officers or back at the station. Furthermore, there exists no reliable means to verify whether officers correctly administered the HGN and/or properly indicated the results. In fact, the Nassau County Police Department advises it officers not to do it on Video on Refusal cases, instead opting to do in areas that are not videotape. They argue that a person could not see the movements of the eyes, because the camera is too far away. Such an argument begs the questions. 

  • Why doesn’t the County catch up with other Police Departments nationwide who have the equipment to record the administration and results of the test?

  • Why don’t they simply can move he persons face closer to the camera, or even using a zoom on the camera to record the test and results.

If they did it on video they would be exposed that they did it wrong.

Videotaping this test, like all tests, it allows a jury to see if the person administering the test is doing it correctly and the results. Interesting Nassau Police Department does not videotape the administering of the Breath tests, at the station. On those rare occasions that Nassau Police Officers have done it on video, I have seen the most experienced Police do incorrectly in terms of the movements of the pen, time used and then testify at a later date, they did it correctly on an earlier date, when it was not videotaped. How could they do it incorrectly at a later date, and do it correctly on a previous date? Not likely. To eliminate this all Officers are not instructed not to do it on video. To rebut this argument, the Police Officers now are taught to state that they do it on the bench, because they are not sure, a suspect will do it on video, while that argument is somewhat appealing upon for examination it is weak, For given, that the officer is trying to establish he did the test correctly, there is no reason why they should not repeat to administered the test again on video if a person on video submits to other field tests, The simple reason they do not do it, is the majority of the time they do it wrong, and if they did it on video they would be exposed that they did it wrong., which often happens when they give the other field tests on camera. In fact, this is what actually occurred with the very experienced breath tech previous discussed in this article, when he admitted that he gave the not validated, Time Estimation test incorrectly by instructed the suspect in that case, to count in his head, in determining 30 seconds. Although he stated he had never done this before, after reviewing the video in front of the jury, he was forced to admit his “error”. Since the Eyes don’t lie, there is no credible reason why all tests show not be videotaped, the Jurors can use their own Eyes to make their own determinations as to whether the Prosecutor have proven their case, and not have to rely on bias opinions put forth by the Police and their agents. In fact, some smaller departments in Nassau County videotape and audiotape everything from the time the suspects enters into the station to the time they are transferred.

They choose not to do so...

Law enforcement could corroborate their findings through readily available video recording and electronic visual techniques to track and record eye movements, but they instead choose not to do so. Thus, the police give judges and juries nothing other than their own conclusory and subjective notations to evaluate the relevancy and weight of the HGN as it pertains to sobriety testing of the accused.