HGN, the Rules of Evidence and Suppression Hearings

True or False:  An officer does not have to be qualified as an expert to testify about horizontal gaze nystagmus in a hearing on a motion to suppress in an impaired driving case.

This statement is true.

Say what? I’ve written a lot about expert testimony and horizontal gaze nystagmus (HGN) lately, including a post titled “Only Experts Can Testify about HGN.” That post describes the court of appeals’ determination in State v. Godwin, ___ N.C. App. ___ (2016), that N.C. Evid. Rule 702(a1) requires a witness to be qualified as an expert before he may testify to the issue of impairment related to HGN results. But Godwin states the rule that applies to the admission of testimony at trial.  The rules are different at a hearing on a motion to suppress.

How does this issue arise? The HGN test is one of three standardized field sobriety tests that law enforcement officers frequently ask drivers suspected of impaired driving to perform. Thus, an officer’s observation of clues on the HGN test often is relevant to determining whether there was probable cause to arrest the defendant for impaired driving. When an officer attempts to provide such testimony in a suppression hearing, defense attorneys sometimes object on the basis that the officer lacks the requisite expertise or the reported results are unreliable.

What’s the law? Rule 104(a) of the North Carolina Rules of Evidence states that in determining preliminary questions of admissibility—the very issue in a suppression hearing—the court is not bound by the rules of evidence except as to privileges. This means that the evidence rules (including Rule 702) do not apply in probable cause hearings.  As a result, there is no requirement that an officer be formally tendered as an expert under Rule 702 before testifying about HGN at a probable cause hearing. See United States v. Horn, 185 F. Supp.2d 530, 533 n.5 (D. Md. 2002) (concluding that regardless of whether SFSTs are admissible in evidence, they may establish probable cause for DWI); State v. Grier, 791 P.2d 627, 631 (Alaska Ct. App. 1990) (agreeing with the trial court that the HGN test is sufficiently reliable to be considered with other field sobriety tests in determining probable cause).

Of course, evidence of HGN results may also be offered at trial for an impaired driving offense as proof that the defendant was appreciably impaired when she drove. The rules of evidence, including the rule announced in Godwin, do apply in that context.

Confused? You aren’t alone. A 2005 report from the Governor’s Task Force on Driving While Impaired recommended that “the findings of [an HGN] test should be admitted in trial for purposes of proving probable cause.” Given that probable cause to arrest is relevant for purposes of a motion to suppress but not to the issue of a defendant’s guilt on the underlying charges, it is unclear why the task force referred to “proving probable cause” “in trial.” The General Assembly responded to that recommendation by amending Rule 702, which, again, does not apply to hearings on motions to suppress.

Katie, bar the door! Before the defense bar panics, let me quickly say that the inapplicability of the rules of evidence does not mean that there are no boundaries limiting the evidence that may support a finding of probable cause. There are. In forming probable cause, an officer may only rely on reasonably trustworthy information that would support a reasonable belief that the suspect committed an offense. See Beck v. Ohio, 379 U.S. 89, 91 (1964). To support a determination of probable cause, therefore, the results of the HGN test must possess some indicia of reliability such that a reasonable officer could rely upon them in concluding there is a fair probability that the defendant is impaired. See State v. Ruthardt, 680 A.2d 349 (Sup. Del. 1996).

It is the judge’s call. The trial judge determines whether the information relied upon by the officer is reasonably trustworthy. In practice, this determination may not look very different from the judge’s determination of whether the evidence may be admitted at trial. A trial judge might, for example, conclude that an officer must be trained in administering HGN for the results of that test to provide reasonably trustworthy information. See State v. Superior Court In & For Cochise Cty., 718 P.2d 171, 178 (Ariz. 1986) (en banc) concluding that “the testimony presented at the evidentiary hearing regarding the reliability of the HGN test establishes that in the hands of a trained officer the test is reasonably trustworthy and may be used to help establish probable cause to arrest”). The judge might require the State to offer additional evidence of the connection between exaggerated nystagmus and impairment from alcohol. Or she might not. Whatever she decides, her ruling is not subject to the provisions of Rule 702.

22 thoughts on “HGN, the Rules of Evidence and Suppression Hearings”

  1. In light of Rule 104, the evidence at a suppression hearing must still be relevant and objectively reasonable and trustworthy. If an officer can not testify about the correlation between alcohol consumption and its anatomical effect on the eyes or if he can not talk to HGN being peer reviewed or accepted as reliable in the medical community, how can that evidence be deemed relevant or trustworthy? Rule 702/Daubert/McGrady does not limit themselves to the issue of the admittance of expert testimony; they outline a litmus test for relevancy and reliability. No rule of evidence excuses those requirements.

    Under the logic in this post, an officer could testify that he used a ouija board to determine whether to arrest an alleged impaired driver. He would not have to testify about the board’s past accuracy or any criticisms of his witchcraft. It would be enough that he subjectively believed the ouija board to be true. You may think this is an extreme example, but it is the exact one used by the Kansas Supreme Court in ruling that HGN is an untrustworthy method for determining impairment.

    On a slightly different topic, Ms. Denning, it is apparent to all members of the NC defense bar that you have been bending over backwards to invalidate our appellate courts’ recent decisions on HGN. We are finally at a point where HGN testimony is being looked at with the appropriate heightened scrutiny that is necessary for all alleged scientific evidence. Why do you consider this a bad thing? If you are so convinced at the importance of HGN evidence, why not author a post outlining the non-government or university studies done on the accuracy and reliability of HGN?

    We both know why you will never write a post like that, and it has nothing to do with the apparent pro-prosecution bias you’ve exhibited on this issue. It has everything to do with the nonexistence of any such study.

    • Steve: The logic of this post does not support using a ouija board for determinations of probable cause nor does it suggest that the determination of whether an officer has probable cause is a subjective one. It is not.

    • Steve Saad, loved your comment I made one a little more harsh the other day about the school of government and my post got pulled. Your wording and logic was spot on, wait before i comment i must make sure that when i look at the computer and begin to type that my eyes are at a 45 degree angle, i have been trained to determine exactly what a 45 degree angle looks like-i can do it in the rain,in the dark, in the presence of flashing lights and i can do it when i am multitasking, okay now that I have my eyes at a 45 degree angle-i can now see clearly that HGN as used in law enforcement is complete voodoo. Who would make up such an absurd test!!!! What if the angle of onset is 44 degrees!!!!! Voodoo!!! The School of Government should be all over this witchcraft.
      President’s Council of Advisers on Science and Technology issued a report today that concludes that these forensic disciplines lack sufficient scientific validation to be admissible in court:Firearm Tool Mark with respect to marks on expended bullet casings,Shoe Print,Tire Tread,Multiple Source DNA,Bite Marks. They were not asked to examine HGN but we all know were it would end up. Why is the school of government not all over this!!!!!

      • Jesse: I am not sure what happened to your earlier comment. As is evident from the many recent comments that have been posted, we do not screen or eliminate comments on the basis that they are critical of the School of Government.

  2. Wow, HGN is not acknowledged in the scientific field as used by law enforcement. How many times has anyone been given a HGN test in their life time by somebody other then law enforcement!! If the test is so accurate why don’t doctors, nurses and emt personal use it to test a person. Because it is not science. I was a scientist before I was a lawyer, HGN is like blood splatter, hair tests and teeth mark, it’s not science. If I hear one more officer state only alcohol causes HGN I am going to get sick! Any judge that believes in HGN as used by law enforcement should not be a judge. HGN is worthless. 20 years from now people will look back and say can you believe people believed in this stupid test. Wait, the world is flat what was I thinking.

    • Actually Mr Jones hgn is used by eye doctors. Secondly its blood spatter, not splatter. And i dont know which officers you have spoken with but hgn is caused by impairment from three drug categories, cns depressants, dissociative anesthetics, and inhalants. Alcohol being categorized under cns depressants.hgn is not voodoo and has had many peer reviewed articles written in its favor by people of the optometry field, Dr Citek, Dr. Forkiotis just to name two. Im assuming since you seem so mad at this issue that you are getting beat in court due to hgn test. Instead of crying about It, do your own research and make a decision based on facts. The hgn test is not voodoo and is an extremely reliable test for impaiment. The 45 degrees is not exact, its an estimate. Just simply looking for hgn to begin prior to that estimated angle.

  3. This interpretation of Rule 104 is inaccurate. Rule 104 generally requires that the rules of evidence be applied to motion hearings. The only exceptions set forth in the Rule related to “preliminary questions of admissibility.” This phrase, as modified by the included examples, applies to hearings to determine whether evidence is admissible under the rules of evidence. On the other hand, a suppression motion is a determination under constitutional and statutory rules whether the remedy of exclusion should be applied to presumably admissible evidence that has arguably been obtained in violation of a defendant’s statutory or constitutional rights. Suppression hearings are not “evidentiary rulings” or rulings to determine “admissibility” as that phrase is used in the evidence code, but rather are substantive determinations of the constitutional rights of the parties. This is the reason law students are taught the exclusionary rule in criminal procedure, not evidence class. Lastly, the next judge who adopts this reading of Rule 104 will be the first. There is no North Carolina case which adopts the reading advocated in this post.

    • Andrew: The court of appeals stated in State v. Ingram, 774 S.E.2d 433, 440 (N.C. Ct. App. 2015) that “Rules 104(a) and 1101(b)(1) of the North Carolina Evidence Code state explicitly the rules of evidence do not apply in suppression hearings.”

      • The cases cited by the Ingram court for this proposition clearly do not support their conclusion. Also, the Court obviously had not read St. v. Foster, 222 N.C. App 199, (2012) where the Court said: “Rule 101 of the North Carolina Rules of Evidence provides: “These rules govern proceedings in the courts of this State to the extent and with the exceptions stated in Rule 1101.” The State urges that a motion does not constitute a proceeding. We cannot agree. If we were to adopt the State’s position, then the Rules of Evidence would not apply to motions to suppress or motions for appropriate relief in criminal cases or motions for summary judgment in civil cases. Obviously, that cannot be the law.” I believe that the long standing rule in this state is that one COA panel cannot overrule another, so I would submit the earlier opinion in Foster should be deemed controlling.

        • Andrew: Your comment is quite misleading. State v. Foster addressed the applicability of the rules of evidence to a post-conviction motion. The comment you cite above, to the extent it addresses motions to suppress, is dicta that is not binding on a subsequent panel of the court of appeals. Furthermore, the aspect of N.C. Evid. R. 104(a) discussed above is similar in all significant respects to Rule 104(a) of the Federal Rules of Evidence. Federal courts have, on numerous occasions, recognized that Rule 104 applies to suppression hearings. See, e.g., United States v. Cartledge, 928 F.2d 93, 95 (4th Cir. 1991) (recognizing applicability of Rule 104 of the Federal Rules of Evidence to hearings on motions to suppress); United States v. Banks, 93 F. Supp. 3d 1237, 1246–50 (D. Kan. 2015) (“Rule 104(a), and the case law interpreting it, are clear: a motion to suppress evidence presents a preliminary question . . . . Just as Rule 104(a) dispenses with the normal bar against hearsay evidence at a suppression hearing . . . so too does it relieve the Court of its duty to conduct a Daubert analysis before considering expert testimony.”); see also United States v. Matlock, 415 U.S. 164, 173–74 (1974) (“That the same rules of evidence governing criminal jury trials are not generally thought to govern hearings before a judge to determine evidentiary questions was confirmed on November 20 last year when the Court transmitted to Congress the proposed Federal Rules of Evidence. Rule 104(a) provides that preliminary questions concerning admissibility are matters for the judge and that in performing this function he is not bound by the Rules of Evidence except those with respect to privileges. Essentially the same language on the scope of the proposed Rules is repeated in Rule 1101(d)(1). The Rules in this respect reflect the general views of various authorities on evidence.”)

          • Even if the statement in Foster is dicta with respect to suppression hearings, it is certainly better reasoned than the holding in Ingram. It is also of great concern that the Ingram court did not even mention or discuss Foster. But lets be fair about what the federal cases actually say. Even in federal court, while a judge would not have to conduct a full Daubert hearing, “Even at a suppression hearing, the district court must always consider any proffered expert’s qualifications and determine, in its discretion, what weight to afford that expert’s testimony. United States v. Diaz, 25 F.3d 392, 394 (6th Cir. 1994). So, while the federal judge does not have to conduct a full Rule 702 hearing, this does not mean that HGN evidence, for example, would be automatically or presumptively admissible in a federal court suppression hearing. The point here is that a trial judge hearing a suppression motion is still going to be under an obligation to consider whether the profered expert opinion is credible and reliable. As a practical matter, a Rule 702 hearing to some extent would be necessary in order to supply the necessary information to the trial court to make determinations regarding reliability. This is the point that needs to be made.

  4. Dear Shea : I firmly believe you protests too much. I do not like to see anybody bullied, however
    you are apparently asking for such. You HAVE been far from neutral in your posts. You ARE bending over backwards to appease those who seek convictions of dwi cases at any costs. Please either remain open minded or announce your blind support for the state. If you fail to admit such the Institute becomes a farce.

  5. This is directed to Michael Pearson. I was a scientist before I was a lawyer. I could talk for days and days about the science behind HGN. I invite you to come let me cross you about HGN. Where I work, our Judges agree with me on HGN. My anger is because the courts keep allowing junk science into the court room to convict. I will always call it blood splatter-because in my mind that is what it is.

    In the past decade, eye movement research has brought to light various problems concerning HGN testing. Unfortunately, the biggest obstacle lies with the most significant portion of the test: smooth pursuit. NHTSA provides instructions for the smooth pursuit phase of the test, administering this portion with uniform velocity and proper motion proves to be a difficult task for any individual. For instance, “[m]oving a stimulus at a constant speed in a straight line is not a natural motion.” An increase in speed could result in a saccade, which could be mistaken as nystagmus. Thus, “variations among different test administrators may have a direct effect on HGN’s validity.” Furthermore, “the maximum speed of smooth pursuit tracking varies greatly across people [and] stimulus conditions.” If an officer follows the NHTSA manual’s two-second pass rule, “this translates to an average speed that is barely within many people’s smooth pursuit capacity.” If the speed goes beyond a person’s capacity, brief catch-up saccades will result and it will appear as if an alcohol-related nystagmus is present. Thus, these imperfections in the standardization of the test limit the reliability, validity, and accuracy of the HGN results. In addition to procedural difficulties, age and gender are other factors which cause a decline in smooth pursuit performance. The reason performance corresponds with age is because “smooth pursuit is an age dependent motor system.” “As people age, they react less quickly to the initial stimulus movement , show a reduced [ratio of the eye speed to that of the target], and require more catch-up saccades to track adequately.” Alarmingly, a substantial decrease in performance begins in the early age group of thirty-one to forty years old. Moreover, there is evidence that women perform worse in HGN testing than men of the same age. Not only do age, gender, and testing techniques affect smooth pursuit, but a significant number of environmental conditions, medical conditions, and side effects from prescription drugs also interfere with an individual’s ( Karl Citek stated this Mr. pearson).
    In Shultz v. State,( not a north Carolina case)(but cited in North Carolina cases,) court laid out a laundry list of factors, aside from alcohol, which cause nystagmus. They include: (1) problems with the inner ear labyrinth; (2) irrigating the ears with warm or cold water under peculiar weather conditions; (3) influenza; (4) streptococcus infection; (5) vertigo; (6) measles; (7) syphilis; (8) arteriosclerosis; (9) muscular dystrophy; (10) multiple sclerosis; (11) Korchaff’s syndrome; (12) brain hemorrhage; (13) epilepsy; (14) hypertension; (15) motion sickness; (16) sunstroke; (17) eye strain; (18) eye muscle fatigue; (19) glaucoma; (20) changes in atmospheric pressure; (21) consumption of excessive amounts of caffeine; (22) excessive exposure to nicotine; (23) aspirin; (24) circadian rhythms; (25) acute trauma to the head; (26) chronic trauma to the head; (27) some prescription drugs, tranquilizers, pain medications, anticonvulsants; (28) barbiturates; (29) disorders of the vestibular apparatus and brain stem; (30) cerebellum dysfunction; (31) heredity; (32) diet; (33) toxins; (34) exposure to solvents, PCBS, dry cleaning fumes, carbon monoxide; (34) extreme chilling; (35) eye muscle imbalance; (36) lesions; (37) continuous movement of the visual field past the eyes, i.e., looking from a moving train; (38) antihistamine use. Not included in this extensive list are environmental stimulants and several additional drugs—benzodiazepines, phenytoin, carbamazepine, lithium carbonate, narcotics, choral hydrate, nitrous oxide, and phencyclidine. As stated above, environmental stimulants may also cause temporary nystagmus. The strobe lights on a patrol car, insufficient lighting, strained conditions, and lateral background movement (passing vehicles) have the greatest effects on HGN testing. The NHTSA manual admits that if an individual is facing passing cars or the lights on the patrol car, then optokinetic nystagmus may result. This admission is troubling because most, if not all, HGN tests are administered roadside while police cruiser lights are flashing. In addition, optokinetic nystamus exhibits “catch up” movements similar to those caused by alcohol consumption. Therefore, these environmental conditions only heighten the rate of error, which lessens the reliability of the results. Not only are there numerous other factors affecting smooth pursuit, but some of these causes also produce high percentages of impaired performance. Abnormal smooth pursuit is exhibited in seventy-three percent of patients with either Alzheimer’s disease or Parkinson’s disease and seventy-six percent of patients with multiple sclerosis. Additionally, sixty-nine percent of patients with localized eye disorders and forty-six percent of patients with generalized vascular disease have experienced reduced smooth pursuit and an increase in nystagmus. Though these conditions have high percentages of disrupting smooth pursuit, their effects are still mistaken as alcohol consumption.
    Police officers are only required to ask the individual “whether he or she has any medical impairment that would either prohibit the subject from taking the test or that would affect the test results.” Relying on the subject’s knowledge is injudicious. It is careless because HGN is not of common knowledge. Accordingly, there is a greater chance that the individual will not know whether he possesses a condition causing nystagmus. Lastly, as if the first extensive list of alternate causes of nystagmus was not enough, a second list exists. It reveals forty-seven other types of nystagmus, which are separate from horizontal gaze nystagmus. These additional types of nystagmus are: (1) Acquired; (2) Anticipatory (induced); (3) Arthrokinetic (induced, somatosensory); (4) Associated (induced, Stransky’s); (5) Audio kinetic (induced); (6) Bartel’s (induced); (7) Brun’s; (8) Centripetal; (9) Cervical (neck torsion, vestibular-basilar artery insufficiency); (10) Circular/Elliptic/Oblique (alternating windmill, circumduction, diagonal, elliptic, gyratory, oblique, radiary); (11) Congenital (fixation, hereditary); (12) Convergence; (13) Convergence-evoked; (14) Dissociated (disjunctive); (15) Downbeat; (16) Drug-induced (barbituate, bow tie, induced); (17) Epileptic (ictal); (18) Flash induced; (19) Gaze-evoked (deviational, gaze-paretic, neurasthenic, seducible, setting-in); (20) Horizontal; (21) Induced (provoked); (22) Intermittent Vertical; (23) Jerk; (24) Latent/Manifest Latent (monocular fixation, unimacular); (25) Lateral Medullary; (26) Lid; (27) Miner’s (occupational); (28) Muscle-Paretic (myasthenic); (29) Optokinetic (induced, optomotor, panoramic, railway, sigma); (30) Optokinetic After-Induced (post-optokinetic, reverse post-optokinetic); (31) Pendular (talantropia); (32) Periodic/Aperiodic Alternating; (33) Physiologic (end-point, fatigue); (34) Pursuit After-induced; (35) Pursuit Defect; (36) Pseudo spontaneous; (37) Rebound; (38) Reflex (Baer’s); (39) See-Saw; (40) Somatosensory; (41) Spontaneous; (42) Stepping Around; (43) Torsional; (44) Uniocular; (45) Upbeat; (46) Vertical; (47) Vestibular (ageotropic,geotropic,Bechterew’s,caloric,electrical/faradic/galvanic,labyrinthine,pneumatic/compression, positional/alcohol, pseudo caloric.)

    It is unrealistic to think that a police officer, can distinguish whether he or she is undoubtedly observing the proper clues for HGN. Therefore, scientific proof reveals the unreliability of the HGN test and demonstrates the dire need to independently evaluate the test’s reliability.

    • Mr Jesse Jones, kudos to you for writing such a lengthy post which held my attention to read it to the end. I disclose that I am a DWI enforcement officer and instructor. I hope that you believe that LEOs detest any procedure/test/operation which could incriminate an innocent person. You admit, while subtly, that your lists include causes of nystagmus “separate from [HGN].” LEOs are taught to identify HGN. In my twenty-six year career, I am convinced that the HGN test is highly accurate. Let me be brief in responding to your post: You are presenting that officers looking for apples (HGN) do not know the difference between apples and other pieces of fruit (nystagmus).

    • Mr Jones,

      The thought of you cross examining me in court is NOT a scary one, I’ve had attorneys like you cross examine me and I’m sure I’ll have more. Seen one, seen them all.

      You keep saying you were a scientist but do not say what kind. That’s ok, the truth of the matter is this, I am NOT a scientist but I too could talk for days on HGN, SFSTs and impaired driving in general.

      I don’t know what it is that you are calling junk science, you don’t give examples.
      When talking science, it doesn’t matter what’s in your mind, you call it what it is, and report what you see. For example, blood spatter or Horizontal Gaze Nystagmus vs other types of nystagmus.

      Your post does seem to mix apples and oranges, as Mr. Kinney points out, but I’m sure that’s just the defense attorney coming out in you. I will stay on point.
      You have many quotes in your post but none of them are cited so I don’t know where you got your information. For example: “An increase in speed could result in a saccade, which could be mistaken as nystagmus. Thus, variations among different test administrators may have a direct effect on HGN’s validity”. This is incorrect. In fact, if you look at a study called The Robustness of HGN it says that a faster stimulus speed goes to the benefit of the person being tested. In other words, the faster a stimulus is moved it is more likely that an officer will miss the lack of smooth pursuit and not produce this clue.

      You talk a lot about the lack of smooth pursuit, when in reality decisions to arrest are NOT based solely on one clue.

      Yes, other drugs can produce HGN not just alcohol. In my first post I listed the drug categories that will produce HGN, they are CNS Depressants, Dissociative Anesthetics and Inhalants. The drugs you list later in the post are included in these categories. EXCEPT “Narcotics” I don’t know what you mean by this, a drug category known as Narcotic Analgesics DO NOT produce HGN.

      “The NHTSA manual admits that if an individual is facing passing cars or the lights on the patrol car, then optokinetic nystagmus may result”. The manual also recommends facing persons being tested away from lights or traffic.

      It has been my experience that people who have medical conditions that either produce nystagmus or any problems with the eyes are very aware of their conditions and can speak at length as to the problems produced.

      I agree there are multiple other forms of nystagmus, however do not confuse them with HGN. If someone is not a good candidate for the HGN test due to a medical condition, then this test is not administered.

      You stated: “It is unrealistic to think that a police officer, can distinguish whether he or she is undoubtedly observing the proper clues for HGN. Therefore, scientific proof reveals the unreliability of the HGN test and demonstrates the dire need to independently evaluate the test’s reliability”. Really Mr Jones? Why is it so unrealistic? Because we are simply lowly police officers? Are you saying that an officer can’t observe an involuntary jerking of the eye as it gazes to the side? What scientific proof reveals this? You’ve offered none. NHTSA and others have evaluated this test’s reliability. I can send you a list of studies if you would like.

      Mr Jones, now I invite you to look at this test critically and not through the lens of a defense attorney, as you stated several times you are or were a scientist. Look at it as a scientist.

      I would also invite you to attend a wet lab and observe the test in a sober person vs an impaired person.

      As an officer I have administered this test 1000s of times and have found it to be extremely reliable in distinguishing between impaired and non impaired individuals. I have made release decisions based on the HGN test in hundreds of people I’ve tested in my 17 years as an officer. This test is not used simply to arrest.

  6. I’d like to start my comment by stating I respect the work of Professor Denning and her colleagues at the SOG, along with the work of the vast majority of law enforcement professionals in this State. That said, it seems like some comments are delving into personal attacks that are not helpful. No one that has commented is trying to “mislead” others that visit this site. The concern that Jesse and Andy have about the apparent State-biased SOG position on DWI issues is based, I believe, on a history of articles that give guidance to judges and prosecutors on how to deflect defense arguments that are well grounded in some recent appellate decisions. For example, when the US Supreme Court handed down Crawford, it was a very clear-cut decision that undercut the State’s use of affidavits in District Court–especially lab reports. Any hope that this opinion would be applied in District Court was dashed, when District Court Judges (at least in my district) began overruling hearsay and Confrontation Clause objections, by essentially saying we were in District Court and the Crawford opinion really didn’t apply. They did this by citing an older confrontation case decided before Crawford that relied on opinions Crawford disavowed. It appears the argument the defense bar was hearing was based on opinions from the SOG on how to distinguish Crawford in DWI cases, by essentially saying “we are just in District Court.” Of course, this position was demolished by Melendez-Diaz, which was of no suprise from anyone who objectively read Crawford.

    Other examples include SOG positions on how the Rose opinion may not be well grounded, or how the State is entitled to numerous continuances in blood draw cases, notwithstanding speedy trial claims, in order to prepare their cases for trial.

    From my perspective, it seems like the legal scholarship flows in one direction–namely, how to help the State distinguish appellate decisions that are favorable to the defense and/or challenge the status quo in District Court. I don’t see the same analysis applied to State-friendly appellate decisions. This concerns me greatly, as our District Court bench has placed quite a bit of weight on the positions taken by the SOG, who they view as a neutral arbitrator on developing legal questions.

    As far as the competing positions on HGN, one of my biggest concerns is the testimony we often hear from LEO’s that may not have given the same amount of study to the field as the officers who have posted comments on this article. Often I have crossed LEO’s on HGN, after they have given the standard testimony that the defendant exhibited six out of six clues and what this signifies. On cross, these same officers will often feign ignorance about the NHTSA Manual and its instructions on how the test is to be performed, or they will claim to do not have an awareness of other causes of nystagmus.

    If we are going to allow HGN testimony in this State, we need to have LEO’s that are truly trained in the causes of nystagmus, which includes all the other medical and environmental factors that come into play. Otherwise, testimony on this issue becomes somewhat farcical, with LEO’s saying the six clues only indicates impairment and claiming ignorance about any other causes.

    In closing, I hope that the commentary on this site assumes each side is coming from a position of good faith.

  7. Steven J. Rubenzer and Scott B. Stevenson, Horizontal Gaze Nystagmus: A Review of Vision Science and Application Issues, Journal of Forensic Sciences (March 2010) (reviewing prosecution and defense claims about HGN and concluding that “[w]hile the sobriety testing literature provides circumstantial evidence of HGN’s validity when BAC is used as a criterion, the eye movement literature raises serious questions about its use as a roadside sobriety test”)

    Just a start for critiques of HGN

  8. Rich, you stated exactly what i was thinking!!!! This is to Mr. Pearson, I have a degree from NCSU in Zoology/Biology, I worked as a chemist for KABI pharmaceuticals, because I excel in Chemistry. I was a member of the Alpha Epsilon Delta Premedical Society while at NSCU and had planned to attend Medical School until my friends and I were abused by some rogue LEOs one night when driving home from a NCSU football meeting.I can not write like Rich or Andrew: I am not a good speller nor am I a good proof reader but i know science and the HGN test as used by LEOs in court is not science. 100 years from now people will laugh about how HGN was used by our courts. I can not laugh, because I am crying due to the fact; courts are constantly letting in evidence that is pure Voodoo. I pray that the school of government with all their brain power could start blogging about and reporting these issues with the problems of courtroom science. For example, bite marks, tire tracks, shoe impressions, blood splatter, etc etc are all total BS, i could go on and on—–if its a science that grows out of the courtroom mostly it grows just to convict. its usually not science and never will be!!!!!!

    • The HGN is, at best 77% accurate (extenuating circumstances and confounding variables omitted). Imagine if we tried murder cases where the fingerprint or DNA evidence was only 77%?
      I’m a Psychologist and 77% is called “probability” NOT a conclusion or fact in my science. Sure, the HGN can be used as probable cause but NEVER as the sole evidence.
      Oh wait, I was just convicted based solely on a ill-administered HGN so I guess logic, fact and evidence no longer apply in NC.
      Jesse, contact me at if you see this. I am planning an appeal without that useless lawyer from the trial. I could use help.

      • Oops, forgot my citation & reference.
        State v. Blake (Arizona, 1986) 718 P.2d 171 (Arizona, 1986) (also State v. Superior Court of County of Cochise, 149 Ariz 269, 718 P.2d 171, 60 ALR 4th, 1103)
        “…and the court explicitly ruled that HGN cannot be used to establish BAC quantitivity in the absence of a chemical analysis test” (p. 42).
        “(HGN) test is (only) 77% accurate” (p. 92, 104)

  9. Ms. Benning,

    I’m curious as to your take on our local practice. In my District, at least in District Court, it is not at all unusual to run the suppression concurrently with totality of the trial. In practice, the same judge hears both the suppression evidence, rules for or against suppression, and then moves on with the balance of the proceeding. This makes practical sense, at least in that the same evidence doesn’t get presented twice. However, given your suggestion that my go-to 702(a1) analysis to exclude HGN during a suppression hearing is- as I understand from your article- inappropriate given the nature of the ROE that apply at the suppression hearing, should the defense bar instead be asking to bifurcate the suppression hearing in District Court? Thank you for your time.


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