When May Evidence of HGN Come on Down . . . or In?

The question I am most frequently asked these days is some version of the following:

May a law enforcement officer trained in administering the HGN test testify at trial about a defendant’s performance on the test if no other expert testifies about the relationship between nystagmus and impairment by alcohol?

While the answer obviously is either yes or no, there is more than one way to analyze the issue. Since today is Thursday, I’m going to throw it back to Bob Barker and the Price is Right and give you two showcases to consider.

Showcase No. 1. This one is for our first contestant, the assistant district attorney.

The answer. The legislature has already answered this question, and the answer is yes.

The analysis.  After the North Carolina Supreme Court held in State v. Helms, 348 N.C. 578 (1998), that the HGN test was a scientific test that required a proper foundation to be admissible, the General Assembly enacted Rule 702(a1) of the North Carolina Rules of Evidence to permit a witness “qualified under subsection (a) of this section and with proper foundation” to “give expert testimony solely on the issue of impairment and not on the issue of specific alcohol concentration level relating to . . . the results of a Horizontal Gaze Nystagmus (HGN) Test when the test is administered by a person who has successfully completed training in HGN.” See S.L. 2006-253, § 6; S.L. 2007-493, § 33. The court of appeals in State v. Smart, 195 N.C. App. 752 (2009) interpreted Rule 702(a1) “as obviating the need for the State to prove that the HGN testing method is sufficiently reliable.” Id. at 756.Thus, Smart determined that the trial court did not err in admitting HGN testimony from an officer trained in administering the test.

While Rule 702(a) was amended in 2011 to incorporate the reliability standard from Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), Rule 702(a1) was not amended. Thus, it continues to reflect the legislature’s assessment that HGN testing is sufficiently reliable as a basis for expert testimony.

Showcase No. 2. This one is for our second contestant, the assistant public defender.

The answer. Smart did not survive the adoption of Daubert, and a law enforcement officer who is trained in HGN but has no scientific expertise cannot establish the requisite foundation for the admission of the testimony.

The analysis.  Rule 702(a1) requires that a witness be qualified under Rule 702(a) and that a proper foundation be established for admission of HGN testimony. The cross-reference to subsection (a) means that the foundational requirements for scientific testimony such as HGN changed in 2011. Thus, Smart, which interpreted the requirements under former Rule 702(a) no longer controls. The court of appeals recently hinted at this possibility, noting in State v. Godwin, __ N.C. App. ___, 786 S.E.2d 34 (2016),  that “[w]hile some may even question whether Smart survives the amendment to Rule 702(a), that issue is not the one presently before us.” Id. at __; 786 S.E.2d at 38.  Indeed, Godwin characterized Rule 702(a1) as a limitation on the admissibility of expert testimony, rather than a loosening of admissibility standards, stating that, pursuant to subsection (a1) an expert witness may testify “solely on the issue of impairment and not on the issue of specific alcohol concentration,” and the HGN test must have been “administered by a person who has successfully completed training in HGN.” Id. at __; 786 S.E.2d at 37 (2016).

Under current Rule 702(a), expert testimony, including expert testimony about HGN, must be based on sufficient facts or data and must be the product of reliable principles and methods. A law enforcement officer’s training in HGN testing does not equip him to explain the physiological relationship between the impairment by alcohol and HGN clues. If a law enforcement officer is not qualified to testify about the scientific basis for HGN testing, then the officer cannot establish that the test results are admissible. See State v. Torres, 976 P.2d 20, 32 (N.M. 1999).

In (modified) Price is Right tradition, go ahead and estimate the likelihood that our appellate courts will adopt either showcases’ reasoning.

Of course, these aren’t the only two ways of analyzing the issue.

A judge who agrees that Smart does not survive the amendment of Rule 702 might nevertheless find the law enforcement officer’s HGN testimony admissible.

  • She might conclude that she can take judicial notice of the causal connection between HGN and alcohol consumption pursuant to Rule 201.


See, e.g., United States v. Horn, 185 F. Supp.2d 530, 555 (2002) (finding this connection so well established that it is appropriate to be judicially noted); State v. Taylor, 694 A.2d 907, 911 (Me. 1997) (“The scientific studies, law review articles, and other literature on the subject of HGN testing, as well as the case law, demonstrate that the HGN test is reliable if an officer properly administers it.”). But see People v. McKown, 875 N.E.2d 1029, 1046 (Ill. 2007) (concluding that technical writings about HGN testing “reveal a dichotomy in the scientific community, rather than the unequivocal or undisputed viewpoint necessary for us to take judicial notice. . . . of the general acceptance of the HGN test as a reliable indicator of alcohol impairment”); State v. Witte, 836 P.2d 1110, 1121 (Kan. 1992) (“The reliability of the HGN test is not currently a settled proposition in the scientific community.”); Torres, 976 P.2d at 33 (determining that “judicial notice of the evidentiary reliability of HGN testing would be inappropriate at this time”).

  • She might conclude that the foundation testimony necessary to attribute HGN clues to impairment from alcohol can be provided by a law enforcement officer with specialized training.


See State v. Ruthardt, 680 A.2d 349, 362 (1996) (“The foundation testimony need not come from a scientific or medical expert; testimony from a Delaware police officer with specialized training in HGN will suffice.”). But see Horn, 185 F. Supp.2d at 555 n.44 (“[A] police officer is unlikely to have the qualifications needed to testify under Rule 702 as to the scientific principles underlying the HGN test or as to whether there is a causal link between alcohol use and exaggerated nystagmus.”)

  • She might conclude that the officer’s experience in administering the HGN test and subsequently viewing chemical testing results, combined with his training, render the officer an expert on the correlation between HGN and impairment.


Cf. State v. Hullinger, 649 N.W.2d 253 (N.D. 2002) (recounting officer’s testimony that he had administered the HGN test 50 times and that he had not observed anyone fail the test who registered less than a 0.10 percent blood alcohol concentration).

It seems likely that, whatever analysis state trial courts adopt, our appellate courts soon will be called upon to clarify this issue. I, for one, can’t wait.

Court of appeals, come on down!

10 thoughts on “When May Evidence of HGN Come on Down . . . or In?”

  1. You note that United States v. Horn finds the causal connection between HGN and alcohol consumption to be “so well established that it is appropriate to be judicially noted pursuant to Rule 201.” It is important to note that this statement in Horn is immediately followed by “That being said, however, it must quickly be added that there also are many other causes of nystagmus that are unrelated to alcohol consumption.” Horn then proceeds, in a footnote, to lay out 38 other possible causes of nystagmus, and says “The fact that there are many other causes of nystagmus in the human eye also is the type of adjudicative fact that may be judicially noticed under Rule 201.”

  2. How can a judge take judicial notice of a connection that may not have been established by sound science in compliance with Daubert? Also, what exact connection is the judge going to take notice of? Can the judge take notice also of the impairing nature of particular drugs? Good bye DRE, you’re not needed.

  3. Great question. Simply put – a judge cannot. HGN is the brainchild of the government, practitioners of which solely work for and are trained by the government, and no entity recognizes it as so much as a “thing” except… The Government. It fails to meet the Daubert requirements there without addressing the other pitfalls set out above.

    If scientific testimony fails to meet the Daubert requirements of reliabilty through the scientific – not law enforcement – community, then it should be of no matter whether the rules of evidence apply at pretrial hearings. Why? Because no weight should be given such witchcraft anyway.

    The laughable scenarios of how a judge can circumvent this reality given above are just another prime example in a long line of the same as to why this blog has lost all credibility while falling over itself to assist judges in circumventing viable arguments from the defense. The NCSOG is what it is – an executive branch entity that purports to be something else under the guise of providing unbiased interpretation of laws. The interpretation of laws lies in the sole province of the judicial branch. These government-paid lawyers speaking to judges on matters pending before the court are breaking nearly every professional obligation mandated of lawyers in this state in one fell swoop of arrogant grandstanding. These self-described “experts” allegedly “specializing” in areas of law for which the NC Bar offers no recognition as a specialist on their books published and provided to judges would be wise to become better acquainted with the Rules of Professional Conduct instead of waxing poetic about matters that should be left to the branch of government for which they are intended.

    Lawyers across this state are fed up with the meddling by the School of Government in cases for which the SOG is a party to the action. This is sixth grade civics – not some difficult legal matter requiring great legal analysis. Such “experts” and “specialists” surely mastered the 6th grade prior to annointing themselves the mater of all things legal, right?

    The obvious and understandable lean of the School of Government to manipulate the law in favor of the government has gotten so outrageously out of hand that the SOG has lost its way. It is too big for its britches an old timer might say.

    I give this piece of advice to all judges and lawyers reading this page – see the above careful dissection of the caselaw. See how phrases were carefully chosen and ommited to further the agenda of the government. Then ask yourself if you should not read behind these supposed “experts” and “specialists” before accepting their interpretations of the law. There are endless examples of this selective reading and misrepresentation.

    As practicioners and DA’s and judges we are at least as equipped for and capable of interpreting the laws of this state as any other lawyer – especially those who do not enter our courtrooms and see the laws of this state in action. The SOG has been accepted through the years as something it is not. Be wary all of you lest we further allow the erosion of the very pillars that hold up the greatest criminal justice system in the world. Judges – you be judges. Lawyers – you be lawyers. Professors – why don’t you go teach what you want and when your branch-mate DA calls please feel free to give your government-leaning argument to them to use in court at a time when all can be heard as to whether your opinions are viable or laughable. Stop giving legal advice to the judicial branch on how to interpret the laws of this great State. It’s not your place in the world despite whatever you have been erroneously told. Judge Wynn smelled a rat years ago but no one has yet to pick up his torch. Consider it done. This racket will stop.

  4. The position I took in State v. Torrence was that the amended Rule 702 brought us back to the State v. Helms holding, which declined to find HGN was sufficiently reliable, even though the officer who testified passed the three day standand field sobriety testing course most LEO’s in this state took to be able to administer the HGN test. Gordon Widenhouse made the same argument–successfully–in State v. Godwin. Interestingly, the State sought discretionary review in Godwin, but opted not to appeal State v. Torrence. I think the answer may come should the Supremes grant review in Godwin. I know there is another case at the COA with the same issue tee’d up, with an opinion hopefully to come soon.

    Let me posit this question: If you were experiencing nystagmus, would you consider a police officer a sufficient source of knowledge to diagnose why you had the symptoms of nystagmus (i.e., twitching eyes)? Or, would you go elsewhere for your expert advice?

  5. It’s certainly interesting that all of the alternative analysis shown in the bullet points at the conclusion regarding what the judge might do happen to be directly related to admission and not denial of the testimony. What a surprise. Goes kind of hand in hand with Mr. Rhor’s observation regarding the incomplete reference to Horn and how it can be used for admission purposes.

  6. Duane’s Ophthalmology, the eye textbook used in medical schools, has this to say about HGN: “It is unreasonable to have cursorily trained law officers using the test, no matter how intelligent, perceptive and well-meaning they might be. As noted, meticulous history taking and drug-screening blood studies are often essential in evaluating patients with nystagmus. Peer-reviewed, research studies have demonstrated that significant number of normals have gaze-evoked nystagmus at small gaze angles (ie. 10 or 20 degrees). Because the pseudoscientific basis for the HGNT has been shown to be demonstrably false, its continued use to convict innocent drivers is untenable; the roadside HGNT should be discontinued in all states currently employing it, and its evidentiary acceptance by the legal system overturned.” So says the medical community.

  7. The validity of HGN is in serious question by the scientific community. Further, the correlation studies conducted by NHTSA have been called into question by several scholarly reviews as being skewed and not reflective of “in the field” administration of the HGN test. I would encourage the readers of your post to thoroughly read the studies conducted by NHTSA and scholarly articles that critique these studies. In almost every single instance, an officer has received about 3-4 hours of study on the HGN test when he/she receives training in SFSTs; a few hours more if he/she receives training in the ARIDE course. I have yet to see an officer who could answer the basic questions involving how the consumption of alcohol causes nystagmus or how other (i.e. medical, environmental, mental, or situational) circumstances can likewise cause nystagmus. Under these conditions, an officer is not and should not be accepted as an expert. Case in point. This week in front of a jury, an officer was accepted as an expert on HGN and thereafter, on cross, stated I have no medical training and Im not a doctor, not an expert and cant answer your questions.

  8. I was a scientist before I was a lawyer and HGN is pure BS as used in our court system. If this test is so spot on; why don’t trained medical personal use it in emergencies, any time you see a test created by law enforcement and used only by law enforcement tells u; ooops this is probably some voodoo crap used to convict people. Why doesn’t the school of government try to help weed out junk science!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I forgot the school of government is not for the people its for the state. sorry. I was thinking you guys were unbiased and fair toward the citizens of the state, I forget you guys do anything to help our police state get convictions. No I am not crazy-just tired of the same stuff happening day after day-in our court system. Sorry I do not write like Les and Rich.

  9. They deleted my comments because I made statements that I think the school of government is biased and slanted for the state in these posts. If you act like your a thinker,and you think HGN IS GOOD science,then guess what, the world is flat.

  10. I’ve got four filing cabinets full of arrest reports, and not a single driver has “passed” the HGN test. This is especially interesting when the driver’s blood test comes back with a 0.000 BAC. Either the HGN test is as rigged as a carnival game, or cops lie. Either way, HGN “evidence” needs to be preserved on video to show the jury, or else it shouldn’t be let in.


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