People v. McKown

Docket No. 102372.

IN THE
SUPREME COURT
OF
THE STATE OF ILLINOIS

THE PEOPLE OF THE STATE OF ILLINOIS, Appellee, v.
JOANNE McKOWN, Appellant.

Opinion filed September 20, 2007.

JUSTICE BURKE delivered the judgment of the court, with
opinion.
Chief Justice Thomas and Justices Freeman, Fitzgerald, Kilbride,
Garman, and Karmeier concurred in the judgment and opinion.

OPINION

At issue in this case is whether the trial court properly admitted
testimony regarding the results of a Horizontal Gaze Nystagmus
(HGN) test 1 at defendant Joanne McKown’s trial for driving under the
influence of alcohol. Over objection, the trial court admitted the
testimony of the arresting officer regarding the administration and
results of an HGN test performed on defendant without first holding
an evidentiary hearing pursuant to Frye v. United States, 293 F. 1013
(D.C. Cir. 1923) (a “Frye hearing”) to determine whether HGN

1
All references to the HGN test in this opinion refer not to the procedure
performed in a laboratory or other controlled setting, but to that administered
by law enforcement officers to individuals suspected of driving under the
influence of alcohol.
testing had been generally accepted as a reliable indicator of alcohol
impairment.2
The trial court admitted the testimony by taking judicial notice of
the general acceptance of the reliability of the HGN test as an
indicator of alcohol impairment based on previous Illinois opinions.
The appellate court affirmed the trial court, agreeing that a Frye
hearing was not necessary. No. 3–04–0433 (unpublished order under
Supreme Court Rule 23).
For the reasons that follow, we hold that the trial court and the
appellate court erred in taking judicial notice of the general acceptance
of the reliability of the HGN test as an indicator of alcohol
impairment. We remand this cause to the trial court with instructions
to conduct a Frye hearing.

BACKGROUND
After a bench trial, defendant was found guilty of two counts of
aggravated driving under the influence of alcohol (625 ILCS
5/11–501(d)(1)(C) (West 2006)), two counts of aggravated reckless
driving (625 ILCS 5/11–503(c) (West 2006)), one count of reckless
driving (625 ILCS 5/11–503(a) (West 2006)), and one count of
driving under the influence of alcohol (625 ILCS 5/11–501(a)(2)
(West 2006)). The evidence against her consisted of three witness
accounts and the observations and opinion of a police officer who
administered an HGN test to her.
The HGN test purportedly measures nystagmus, which has been
defined as an abnormal and involuntary rapid movement of the
eyeballs up and down, or more commonly, side to side. 2 Schmidt’s
Attorney’s Dictionary of Medicine 61 (1978). Many people will
exhibit some nystagmus, or jerking, as their eyes track to the extreme
side. However, with an intoxicated person, the onset of the
nystagmus, or jerking of the eyeball, occurs after fewer degrees of
lateral deviation from center, and the jerking is more pronounced at

2
The parties have not argued, and we have not considered, the adoption
of the evidentiary standard set forth in Daubert v. Merrell Dow
Pharmaceuticals, Inc., 509 U.S. 579, 125 L. Ed. 2d 469, 113 S. Ct. 2786
(1993). We will not raise the issue sua sponte.

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extreme angles. While nystagmus is an indication of alcoholic
consumption, it is also a symptom of many other ailments. N. Miller
& N. Newman, Walsh & Hoyt’s Clinical Neuro-Ophthalmology 1142
(6th ed. 2005).
Because alcohol consumption can cause nystagmus, police officers
have been trained to check a person’s eye movements when
attempting to determine if a driver has been driving while impaired by
alcohol. The National Highway Traffic Safety Association’s (NHTSA)
DWI Detection and Standardized Field Sobriety Testing Instructor
Manual sets forth the procedure for administering an HGN test in the
field. First, the officer is required to ask the subject if he or she wears
contact lenses or has any medical impairment that would affect the test
results or prohibit the subject from taking the test. If the subject claims
to wear hard contacts, or have natural nystagmus or any other
condition that may affect the test results, the officer should note the
condition but still administer the test if possible. NHTSA DWI
Detection and Standardized Field Sobriety Testing Instructor Manual,
ch. VIII, at 6-18 (2002).
After these preliminary questions, the officer asks the subject to
focus on an object, such as a pen, held just above eye level, about 12
to 15 inches from the subject’s nose, and to follow the object as the
officer gradually moves it from side to side.
While conducting the test, the officer looks for six nystagmus
“clues,” three in each eye, that, according to the NHTSA Manual,
indicate impairment. If four or more clues are present, the subject is
determined to have failed the test and be impaired. The clues are (1)
lack of smooth pursuit; (2) distinct nystagmus at maximum deviation,
meaning any nystagmus exhibited when the eyeball is looking as far to
the side as possible; and (3) angle of onset of nystagmus prior to 45
degrees, meaning any nystagmus that occurs before the object reaches
a point that the officer determines to be 45 degrees from the center of
the suspect’s face. No measuring apparatus is used in the 45-degree
test. The officer is then instructed to have the subject perform the
walk-and-turn field-sobriety test and the one-leg-stand field-sobriety
test, compile the results of the three tests, and then make the decision
whether to arrest the subject. NHTSA DWI Detection and
Standardized Field Sobriety Testing Instructor Manual, ch. VIII, at 6-
18 (2002).

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 At a bench trial, witnesses testified that, sometime before 11:30
a.m. on the morning of June 8, 2002, defendant was driving her car at
a high rate of speed along Maher Road in Peoria County when she
veered into oncoming traffic, causing at least three motorcycle riders
who were traveling in the opposite direction to strike her vehicle and
be thrown from their motorcycles. Two riders, Sharon and Alan
Anderson, suffered severe injuries. Another rider, Robert Stanley, was
thrown from his motorcycle but escaped relatively unharmed.
Local resident Randall Retherford testified that he was driving his
truck on Maher Road around 11:30 a.m. on June 8, 2002. While idling
at the intersection of Maher Road and Frye Road, waiting for a group
of motorcycles to pass so he could make a left turn onto Frye, he
looked into his rearview mirror and saw defendant’s car approaching.
Retherford stated that he drove his truck onto the shoulder of the road
upon seeing defendant’s car because he felt it was approaching at a
high rate of speed. Retherford then described the accident: “I seen
[sic] the vehicle apparently lock up its wheels, veer to the left, and I
seen [sic] motorcycles hitting it.”
Retherford’s testimony was corroborated by Stanley, who also
testified that, following the accident, defendant came over to him as
he lay on the ground and offered to help him remove his motorcycle
helmet. Stanley testified that, during the approximately 45 seconds
defendant was speaking to him, he smelled beer on her breath.
A third witness, Chad Morris, testified that he had been riding a
motorcycle behind the Andersons and Stanley, when he saw
Retherford “getting off the side of the road because he had seen, um,
a car coming up fast on his tail.” Morris testified that he heard
squealing tires and witnessed defendant’s car veering into his lane and
sliding sideways into the oncoming motorcycles. Morris stated that he
was able stop his motorcycle in time to avoid contact with defendant’s
car.
The arresting officer, Deputy Martin Klatt of the Peoria County
sheriff’s department, testified that he arrived at the scene of the
accident shortly after 11:30 a.m. and found a partially full can of beer
in defendant’s car while searching for her registration and proof of
insurance. Apparently, defendant had been taken to St. Francis
Hospital before Klatt arrived at the accident scene. Klatt testified that
he went to the hospital and advised defendant of her Miranda rights
around 1 p.m. According to Klatt, when he saw defendant, she was

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slurring her speech, and had bloodshot eyes and a strong odor of beer
on her breath. Klatt testified that defendant told him that she had not
been drinking that day, and that she felt that the motorcycles came
into her lane, causing the accident.
When Klatt told defendant that he had found an open can of beer
in her car, she admitted that she had consumed two cans of beer
before leaving her house, another can while driving, and had opened
a fourth can just prior to the accident. Klatt then advised her that the
skidmarks on the road indicated that she swerved out of her lane and
into the oncoming motorcycles. Upon hearing this, defendant stated
that she had no explanation for what happened. Klatt testified that
defendant stated that she worked the night shift at a chemical plant
and had only slept for four hours the previous night.
Klatt then testified that he administered an HGN test to defendant
while she sat in her hospital bed. Defendant objected to Klatt’s
testimony, arguing that HGN test results are scientific evidence that
has not been found to satisfy Frye in Illinois. After a discussion with
counsel, the trial court took judicial notice of the plurality opinion in
People v. Basler, 193 Ill. 2d 545 (2000) (plurality op.), and held that
the HGN test met the Frye standard.
Klatt described the HGN test to the court, stating that it was “an
eye test and it uses the involuntary flutter of your eye, and it’s been
shown that certain–that when you’re under impairment of alcohol, and
some drugs, that your–when your eye is moving a certain way that it
will involuntarily shutter, or shake, or jerk.” Klatt explained that he
had been trained in performing the HGN test, and that he had
administered the HGN test “hundreds of times” in the field. Klatt did
not provide any details regarding his training.
Klatt testified that, while he was performing the test on defendant,
he “observed that she had no smooth pursuit with either eye[,] ***
nystagmus on maximum deviation with both eyes” and nystagmus in
both eyes during the third part of the test. Klatt testified that these
results led him to conclude that defendant had failed the HGN test and
was impaired by alcohol. Klatt did not have defendant perform any
other field-sobriety tests due to the fact that she had a broken toe. On
cross-examination, Klatt conceded that he was aware that defendant
had been given medication at the hospital before he administered the
HGN test, which could have affected her results.

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 After Klatt concluded that defendant had failed her HGN test, he
placed her under arrest and directed her to submit to chemical testing
to determine her blood-alcohol content. Defendant refused to comply
with efforts to conduct the chemical tests upon her. However, she
subsequently submitted to the tests when the police obtained a search
warrant several hours later.
At trial, the parties stipulated that if Dareea Paiva, a forensic
specialist with the Illinois State Crime Laboratory in Springfield, were
to testify, she would state that she received a kit from the Peoria
County sheriff’s department containing two tubes of blood taken from
defendant around 6 p.m. on June 8, 2002. The parties further
stipulated that Paiva would testify that studies on the blood samples
taken from defendant that evening did not reveal the presence of
ethanol, methanol, acetone, isopropanol, tolume, or other volatiles.
The trial court found defendant guilty of all six counts against her.
Defendant filed a motion for a new trial, arguing that Klatt’s testimony
regarding her HGN test results was improperly admitted without a
Frye hearing. The trial court denied the motion and sentenced
defendant to two years’ imprisonment for her convictions of
aggravated driving under the influence.
On appeal, defendant argued, inter alia, that the trial court
improperly allowed Klatt’s testimony regarding her HGN test results.
The appellate court affirmed, ruling that the trial court properly
admitted Klatt’s testimony. The appellate court held that it was not
necessary for the trial court to conduct a Frye hearing before
admitting defendant’s test results. Taking judicial notice of People v.
Wiebler, 266 Ill. App. 3d 336 (1994) and the plurality opinion in
Basler, the appellate court concluded that HGN testing is generally
accepted in the scientific community as a reliable indicator of alcohol
impairment. No. 3–04–0433 (unpublished order under Supreme Court
Rule 23). We granted defendant’s petition for leave to appeal. 210 Ill.
2d R. 315.

ANALYSIS
Here, as in the appellate court, defendant argues that she was
denied a fair trial because the trial court allowed her HGN test results
to be admitted as scientific evidence without first holding a Frye
hearing to determine whether the HGN test had been generally

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accepted as a reliable indicator of alcohol impairment by the relevant
scientific community. In Illinois, scientific evidence is admissible at
trial only if it meets the standard expressed in Frye, which dictates that
“scientific evidence is admissible at trial only if the methodology or
scientific principle upon which the opinion is based is ‘sufficiently
established to have gained general acceptance in the particular field in
which it belongs.’ ” In re Commitment of Simons, 213 Ill. 2d 523,
529-30 (2004), quoting Frye, 293 F. at 1014. A court may determine
the general acceptance of a scientific principle or methodology in
either of two ways: (1) based on the results of a Frye hearing; or (2)
by taking judicial notice of unequivocal and undisputed prior judicial
decisions or technical writings on the subject. K. Broun, McCormick
on Evidence §203, at 828-39 (6th ed. 2006). See also Jones v. United
States, 548 A.2d 35 (D.C. App. 1988). At issue here is whether it was
proper for the trial court to forgo a Frye hearing and determine the
general acceptance of the reliability of the HGN test as an indicator of
alcohol impairment by taking judicial notice of prior decisions. Our
review is de novo. In re Commitment of Simons, 213 Ill. 2d at 531.

I. HGN Testing Is Scientific
Because Frye applies only to scientific evidence, we first must
determine whether the results of HGN testing are scientific evidence
subject to the Frye standard. Scientific evidence is the product of
scientific tests or studies. Evidence labeled “scientific” carries a
greater weight in the eyes of the jury, which may accord it undue
significance because “science” is equated with truth. M. Udall & J.
Livermore, Law of Evidence §102 (2d ed. 1982). For this reason,
Illinois courts require any evidence which is “scientific evidence” to
meet the Frye standard.
Initially, we note that the matter at issue is not the scientific
principle underlying the HGN test, but rather the test itself. Defendant
concedes the general acceptance of the scientific principle that alcohol
consumption can cause nystagmus. What defendant challenges is the
use of the HGN test as the methodology employed to generate the
conclusion that a defendant is impaired by alcohol. See Donaldson v.
Central Illinois Public Service Co., 199 Ill. 2d 63, 77 (2002) (the
proper focus in Frye hearings is on the methodology that was used to
generate a proffered conclusion).

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 Some jurisdictions have held that HGN testing is not scientific,
and therefore the evidence the HGN test produces does not need to
meet any of the Frye requirements for admission. See State v.
Bresson, 51 Ohio St. 3d 123, 129, 554 N.E.2d 1330, 1336 (1990)
(“HGN test cannot be compared to other scientific tests such as a
polygraph examination, since no special equipment is required in its
administration”); State v. Murphy, 451 N.W.2d 154, 156 (Iowa 1990)
(because the test may be easily administered and its results objectively
recorded by a properly trained officer, it is unnecessary to establish the
foundation for such evidence through scientific testimony). Several
other states have also concluded that HGN testing does not produce
scientific evidence. See Whitson v. State, 314 Ark. 458, 863 S.W.2d
794 (1993); City of Fargo v. McLaughlin, 512 N.W.2d 700 (N.D.
1994); State v. Sullivan, 310 S.C. 311, 426 S.E.2d 766 (1993).
The majority of jurisdictions that have addressed the issue,
however, have held HGN testing to be scientific because it is based on
a scientific principle that is not common knowledge, i.e., consumption
of alcohol causes the type of nystagmus measured by the HGN test.
See State v. Reed, 83 Or. App. 451, 454-55, 732 P.2d 66, 68 (1987)
(certain reactions to alcohol are so commonly known that they are not
considered scientific evidence, but nystagmus does not fall into this
category); State v. Witte, 251 Kan. 313, 321, 836 P.2d 1110, 1115
(1992) (HGN test differs from other field-sobriety tests in that
science, rather than common knowledge, provides the legitimacy for
HGN testing); State v. O’Key, 321 Or. 285, 296-97, 899 P.2d 663,
675 (1995) (“The relationship between the effects of alcohol on the
*** HGN test is not within the realm of common knowledge of the
average person”); and State v. Murphy, 953 S.W.2d 200, 203 (Tenn.
1997) (HGN testing is scientific because the underlying basis of the
test has to be explained in order for the testimony to make sense to
the average juror). See also Ex parte Malone, 575 So. 2d 106 (Ala.
1990); People v. Leahy, 8 Cal. 4th 587, 882 P.2d 321, 34 Cal. Rptr.
2d 663 (1994); State v. Merritt, 36 Conn. App. 76, 647 A.2d 1021
(1994); State v. Meador, 674 So. 2d 826 (Fla. App. 1996); State v.
Witte, 251 Kan. 313, 836 P.2d 1110 (1992); Commonwealth v. Sands,
424 Mass. 184, 675 N.E.2d 370 (1997); People v. Berger, 217 Mich.
App. 213, 551 N.W.2d 421 (1996); State v. Wheeler, 764 S.W.2d 523
(Mo. App. 1989); Hulse v. State, 289 Mont. 1, 961 P.2d 75 (1998);

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State v. Borchardt, 224 Neb. 47, 395 N.W.2d 551 (1986); State v.
Duffy, 146 N.H. 648, 778 A.2d 415 (2001); State v. Torres, 127
N.M. 20, 976 P.2d 20 (1999); People v. Heidelmark, 214 A.D.2d
767, 624 N.Y.S.2d 656 (1995), appeal denied, 85 N.Y.2d 973, 653
N.E.2d 629 (1995); State v. Helms, 348 N.C. 578, 504 S.E.2d 293
(1998); Yell v. State, 856 P.2d 996 (Okla. Crim. App. 1993); State v.
O’Key, 321 Or. 285, 899 P.2d 663 (1995); State v. Murphy, 953
S.W.2d 200 (Tenn. 1997); State v. Barker, 179 W. Va. 194, 366
S.E.2d 642 (1988), overruled on other grounds, Wilt v. Buracker, 191
W. Va. 39, 443 S.E.2d 196 (1993) (adopting the Daubert standard
over the Frye standard).
We agree with those jurisdictions that hold HGN testing to be
scientific. The average person understands the effect that alcohol has
on a person’s balance and motor skills. For this reason, the average
person can draw his own conclusion from the results of field-sobriety
tests such as the walk-and-turn and the stand-on-one-leg. As such, the
results of those tests are not deemed scientific evidence. In contrast,
the results of an HGN test are meaningless to an average person
unless accompanied by expert testimony about what those results
mean and what conclusion may be drawn from them. This expert
testimony comes from police officers, who must be trained to
administer and interpret the HGN test. Because the results of an HGN
test require expert interpretation, we join the majority of courts and
hold that the results of HGN testing are scientific evidence.

II. HGN Evidence Is Novel for Purposes of Frye Testing
In Illinois, the application of the Frye standard is limited to
scientific methodology that is considered “new” or “novel.” Defendant
contends that the HGN test is a novel technique, despite the fact that
it has been used by police officers for many years, because no Frye
hearing has ever been held in Illinois to determine if the HGN test has
achieved general acceptance as a reliable indicator of alcohol
impairment. We agree.
In Leahy, the California Supreme Court held,
“HGN testing has been repeatedly challenged in court, with
varying degrees of success, in this and other states, and

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 accordingly its courtroom use cannot fairly be characterized
as ‘routine’ or settled in law. [Citation.] ***.
Given the recent history of legal challenges to the
admissibility of HGN test evidence in this and other states, it
seems appropriate that we deem the technique ‘new’ or
‘novel’.” (Emphasis omitted.) Leahy, 8 Cal. 4th at 606, 882
P.2d at 332, 34 Cal. Rptr. 2d at 674.
Since Leahy was published in 1994, the general acceptance of
HGN testing has been repeatedly challenged in courts around the
nation, and the issue remains unsettled. As discussed below, our own
appellate court has issued divergent opinions on the topic, with People
v. Wiebler, 266 Ill. App. 3d 336 (3d Dist. 1994), and People v.
Buening, 229 Ill. App. 3d 538 (5th Dist. 1992), taking judicial notice
of the general acceptance of the reliability of the HGN test as an
indicator of alcohol impairment, and People v. Kirk, 289 Ill. App. 3d
326 (4th Dist. 1997), declining to determine general acceptance based
on judicial notice alone. As also discussed below, many states have
addressed the issue of whether HGN testing satisfies Frye since Leahy
was published in 1994, with the same “varying degrees of success”
mentioned in Leahy. Other states have also held that the question of
novelty alone should not prevent a court from considering the larger
issues involved in a Frye hearing. See, e.g., Emerson v. State, 880
S.W.2d 759 (Tex. Crim. App. 1994) (HGN testing considered novel
because Texas courts had not determined if the technique it was based
upon was reliable).
Given the history of legal challenges to the admissibility of HGN
test evidence, and the fact that a Frye hearing has never been held in
Illinois on this matter, we conclude that the methodology of HGN
testing is novel for purposes of Frye.
Having concluded that HGN testing is a novel scientific
methodology, we find that the trial and appellate courts did not err in
determining that HGN testing must meet the Frye standard before
defendant’s HGN test results were admitted as evidence. The ultimate
issue to be determined, however, is whether the lower courts
employed the proper method in determining that the HGN test had
been generally accepted as a reliable indicator of alcohol impairment
by the scientific community.

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 III. Determining General Acceptance
In considering whether the trial court and the appellate court
erred in taking judicial notice of the general acceptance of the
reliability of the HGN test as an indicator of alcohol impairment, we
look not only to the opinions of Basler and Wiebler, but also to other
cases from Illinois and around the nation, as well as the technical
writings proffered by each party. See In re Commitment of Simons,
213 Ill. 2d at 531 (in reviewing a lower court’s Frye analysis, we may
consider sources outside the record, including court opinions from
other jurisdictions, as well as legal and scientific articles).

A. Prior Judicial Decisions
In the instant case, the appellate court took judicial notice of the
general acceptance of the reliability of the HGN test as an indicator of
alcohol impairment based on Basler and Wiebler. No. 3–04–0433
(unpublished order under Supreme Court Rule 23). Defendant argues
that the appellate court erred by taking judicial notice of prior judicial
decisions, rather than on the results of a Frye hearing, in making its
determination. Defendant maintains that a Frye hearing is necessary
because the matter has not been adequately litigated in Illinois, nor
was it adequately litigated in the cases from other jurisdictions that
Illinois cases have relied on, notably State v. Superior Court [Blake],
149 Ariz. 269, 718 P.2d 171 (1986).3
The appellate court below relied on Wiebler, in which the Third
District held that HGN test results are admissible in a prosecution for
driving under the influence of alcohol, but are not conclusive evidence
of intoxication. Wiebler, 266 Ill. App. 3d at 339. Wiebler, however,
merely reaffirmed Buening, which was the first Illinois case hold that
the HGN test was generally accepted as a reliable indicator of alcohol
impairment.
In Buening, the Fifth District held that HGN test results are
admissible to prove that the defendant is impaired by alcohol, in
violation of section 11–501(a)(2), provided a proper foundation has

3
This case has been referred to in various Illinois opinions as State v.
Superior Court, County of Cochise, and Blake. For clarity it shall be
referred to as Blake in this opinion

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been laid. Buening, 229 Ill. App. 3d at 541-46. Buening held that a
proper foundation should consist of describing the education and
experience of the officer who administered the test and by a showing
that the procedure was properly administered. Buening, 229 Ill. App.
3d at 546.
Buening described how HGN testing is treated by numerous
foreign jurisdictions, but did not analyze any of the foreign cases or
apply their reasoning to its facts. Buening, 229 Ill. App. 3d at 541-45.
Instead, the Buening court based its holding of general acceptance on
three reasons: (1) the fact that the United States Department of
Transportation Test Manual called the HGN test “the single most
accurate field test used in determining whether a person is alcohol
impaired”; (2) the NHTSA found that an officer’s ability to detect
whether a driver is under the influence of alcohol improves when the
HGN test is used in conjunction with the walk-and-turn field-sobriety
test (NHTSA, Improved Sobriety Testing (1984)); and (3) the
reasoning set forth in Blake, which Buening called “one of the more
extensively researched and well-reasoned decisions on the subject.”
Buening, 229 Ill. App. 3d at 541.
In Blake, the State of Arizona presented testimony at a Frye
hearing regarding the principles and use of HGN testing from three
police officers and Dr. Marcelline Burns, a research psychologist who
studied the effect of alcohol on behavior. Blake, 149 Ariz. at 271, 718
P.2d at 173. Dr. Burns was identified as the Director of the Southern
California Research Institute (SCRI), which had received research
contracts from NHTSA to develop the best possible field-sobriety
tests. Blake, 149 Ariz. at 271, 718 P.2d at 173. The result of the
SCRI’s research was a three-test battery which included the walk-and-
turn test, the one-leg-stand test, and the HGN test. Blake, 149 Ariz.
at 271, 718 P.2d at 173.
Dr. Burns explained that the HGN test is based on the known
principle that alcohol, among other things, can cause nystagmus.
Blake, 149 Ariz. at 271, 718 P.2d at 173. The SCRI study found the
HGN test to be “the best single index of intoxication,” because the
jerking movements of the eye are involuntary. Blake, 149 Ariz. at 271,
718 P.2d at 173. Dr. Burns then testified that the HGN test had been
accepted as valid by the NHTSA, Finnish researchers, numerous city

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agencies, and the highway patrols of California, Washington, and
Arizona. Blake, 149 Ariz. at 272, 718 P.2d at 174.
Sergeant Richard Studdard, a supervisor in charge of DUI
enforcement for the City of Los Angeles and a consultant to NHTSA
on field-sobriety testing, then testified that, based on his field work
administering the HGN test and his participation in studies at the
institute, the accuracy rate of the HGN test in determining if a
person’s blood-alcohol content is over 0.10% is between 80% and
90%. Blake, 149 Ariz. at 272, 718 P.2d at 174.
Sergeant Jeffrey Raynor, who administered the HGN training
program for Arizona, testified about the usefulness of the HGN test
and the “rigor and requirements of the Arizona training and
certification program.” Blake, 149 Ariz. at 272, 718 P.2d at 174.
While no details of the actual training program were presented in the
opinion, it was explained that an HGN training manual developed by
NHTSA for its nationwide training program was entered into
evidence. Blake, 149 Ariz. at 272, 718 P.2d at 174. This manual, and
the training program, were based on the SCRI’s studies. Blake, 149
Ariz. at 272, 718 P.2d at 174. The opinion states that Officer Robert
Hohn, who administered the HGN test to the defendant, also testified
for the State, but does not elaborate on his testimony. Blake, 149
Ariz. at 271, 718 P.2d at 173. The defendant did not present any
evidence.
At the close of the hearing, the trial court found that HGN testing
was a new scientific principle and thus subject to the Frye standard of
admissibility, but that it did not satisfy Frye and could not form the
basis of probable cause to arrest. Blake, 149 Ariz. at 272, 718 P.2d at
174. The court of appeals vacated the trial court’s order, noting that
the Frye standard applies only to the admissibility of evidence at trial,
not to probable cause for arrest. Blake, 149 Ariz. at 272, 718 P.2d at
174. The court of appeals then held that the HGN test satisfied Frye
and would be admissible, except that there was insufficient foundation
in the underlying case as to the arresting officer’s proficiency in
administering the test. Blake, 149 Ariz. at 273, 718 P.2d at 174-75.
The Arizona Supreme Court affirmed the court of appeals. Blake,
149 Ariz. at 279, 718 P.2d at 181. In analyzing the HGN test under
Frye, the Blake court first set out to “identify the appropriate

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scientific community whose acceptance of the nystagmus principles
and validity of the HGN test is required.” Blake, 149 Ariz. at 277, 718
P.2d at 179. In doing so, Blake stated,
“[I]t stands to reason that experimental psychologists in the
area of behavioral psychology would be interested in verifying
the validity of the HGN test and should be included in the
relevant scientific community. Similarly, the problem of
alcohol’s effect on driving ability is a major concern to
scientists in the area of highway safety and they, too, should
be included.” Blake, 149 Ariz. at 278, 718 P.2d at 180.
Having identified the scientific community it felt was appropriate,
the Blake court then turned to the question of whether that
community had generally accepted the HGN test as a reliable indicator
of blood-alcohol content and alcohol impairment. Blake, 149 Ariz. at
278, 718 P.2d at 180. In its analysis, the Blake court considered the
testimony of Burns and the police officers, as well as the content of 29
scientific publications and reports of research on nystagmus and HGN
testing. Blake, 149 Ariz. at 278, 718 P.2d at 180. The Blake court
noted that the publications it considered “have been before the
relevant communities a considerable period of time for any opposing
views to have surfaced.” Blake, 149 Ariz. at 279, 718 P.2d at 181.
Blake concluded, “[t]he literature demonstrates to our satisfaction that
those professionals who have investigated the subject do not dispute
the strong correlation between BAC and the different types of
nystagmus.” Blake, 149 Ariz. at 278-79, 718 P.2d at 180-81.
Blake then held that “with proper foundation as to the techniques
used and the officer’s ability to use it [citations], testimony of
defendant’s nystagmus is admissible on the issue of a defendant’s
blood alcohol level as would be other field sobriety test results on the
question of the accuracy of the chemical analysis.” Blake, 149 Ariz.
at 279, 718 P.2d at 181. Blake also held that HGN test results were
admissible as evidence that a defendant was driving while “under the
influence of alcohol.” Blake, 149 Ariz. at 280, 718 P.2d at 182.
The reasoning presented in Blake has been followed by many
jurisdictions, as will be discussed below. However, the Fourth District
of our appellate court questioned the Blake analysis in Kirk. In Kirk,
a case involving the admission of HGN test results in a prosecution for

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driving under the influence of alcohol, the trial court admitted HGN
test results as scientific evidence without any Frye hearing taking
place. Kirk, 289 Ill. App. 3d at 327. In its analysis, the Kirk court
examined Buening, and in particular, its reliance on Blake and the
opinions of other courts. Kirk, 289 Ill. App. 3d at 333. In examining
Blake, which it deemed “questionable authority,” the Kirk court was
troubled by the fact that no defense evidence was presented, and that
the trial court, which heard the testimony firsthand, was reversed by
the reviewing courts, which relied on their own research of relevant
articles. Kirk, 289 Ill. App. 3d at 332, 333. The Kirk court was also
troubled by Blake’s reliance on the testimony of the prosecution’s
expert. The Kirk court stated:
“The expert retained by the prosecution in Blake, Dr.
Burns, was the individual who conducted the study that led to
the NHTSA’s adoption of the HGN test. Police departments,
in turn, have adopted the NHTSA’s recommendations. In
Blake, Dr. Burns supported the proposition that the HGN test
is accepted and reliable, in part, by relying upon the NHTSA’s
manual and the fact that the test is used by different police
departments. By doing so, however, she in essence referred
back to her own conclusions, magnifying the opportunity for
error. We do not say that Dr. Burns’ conclusions on the
subject are flawed, only that the issue has not been fully and
thoroughly litigated. The proper place for this litigation is in
the trial court, and it was error to admit the HGN test
evidence without a proper Frye hearing.” Kirk, 289 Ill. App.
3d at 333-34.
The Kirk court then examined the cases from other states that
Buening relied upon and found that four of them deemed HGN test
results to be nonscientific evidence that did not need to satisfy the
Frye standard. Kirk, 289 Ill. App. 3d at 333. The Kirk court found
that, “[o]f the remaining cases, none of the appellate courts had the
benefit of a Frye hearing. Rather, those courts concluded that the Frye
standard had been met due to the Blake court’s conclusion.”
(Emphasis omitted.) Kirk, 289 Ill. App. 3d at 333. The Kirk court did
not approve of Buening’s reliance on these cases, and held that relying
exclusively upon prior judicial decisions to establish general scientific

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acceptance can be a “hollow ritual” if the underlying issue of scientific
acceptance has not been adequately litigated. Kirk, 289 Ill. App. 3d at
333, quoting 1 J. Strong, McCormick on Evidence §203, at 870 n.20
(4th ed. 1992).
The Kirk court then held that it was error to have admitted the
HGN test results “without a proper Frye hearing.” Kirk, 289 Ill. App.
3d at 334. The error was deemed harmless, however, because there
was sufficient non-HGN evidence to establish that the defendant was
impaired by alcohol while operating his vehicle. Kirk, 289 Ill. App. 3d
at 334.
The disparity in how HGN evidence has been treated by the
districts of the appellate court was discussed, but not resolved, by this
court in Basler. In Basler, a jury found the defendant guilty of driving
under the influence of alcohol. Basler, 193 Ill. 2d at 546 (plurality
op.). The appellate court reversed and remanded, holding that the trial
court committed reversible error by, among other things, rejecting the
defendant’s motion for a continuance. Basler, 193 Ill. 2d at 547
(plurality op.). In the defendant’s petition for rehearing, she
challenged the admissibility of the testimony regarding her HGN test
results for the first time. Basler, 193 Ill. 2d at 547 (plurality op.).
Upon rehearing, the appellate court issued a modified opinion, which
again reversed and remanded the cause, but added a discussion of the
HGN testing issue. Basler, 193 Ill. 2d at 548 (plurality op.). The State
appealed to this court.
We affirmed the appellate court’s decision to reverse and remand,
but held that the HGN issue had been waived by the defendant.
Basler, 193 Ill. 2d at 549 (plurality op.). We stated, “The problem
with undertaking such an expansive analysis is that validity of the
HGN test was never challenged in the trial court” or in the defendant’s
posttrial motion. Basler, 193 Ill. 2d at 549 (plurality op.). Although
we held the HGN issue waived, a plurality chose to address the issue
on the merits, and held that HGN testing met the Frye standard.
Basler, 193 Ill. 2d at 551 (plurality op.). Two justices dissented.
Basler, 193 Ill. 2d at 552-60 (McMorrow, J., dissenting, joined by
Freeman, J.). Two other justices concurred only with the result of the
case, and not the plurality’s statements on HGN test results, which
they held to be dicta. Basler, 193 Ill. 2d at 552 (Heiple, J., specially

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concurring, joined by Bilandic, J.). As such, Basler provides no
guidance.4
A review of other Frye states reveals that the general acceptance
of HGN testing is not a settled issue. Our research indicates that, in
the first five years after 1986, when Blake was published, several
courts took judicial notice of the general acceptance of the reliability
of the HGN test as an indicator of alcohol impairment, based on
Blake, and for that reason held that no Frye hearing was needed
before admitting HGN evidence. Malone v. City of Silverhill, 575 So.
2d 101 (Ala. Crim. App. 1989), rev’d on other grounds, Ex parte
Malone, 575 So. 2d 106 (Ala. 1990); State v. Garrett, 119 Idaho 878,
811 P.2d 488 (1991); State v. Armstrong, 561 So. 2d 883 (La. App.
1990). In May 1992, Buening likewise relied on Blake in determining
that no Frye hearing was necessary before admitting HGN test results
in the Fifth District. Buening, 229 Ill. App. 3d at 542.
However, 1992 marked a change in the way many courts chose to
resolve the HGN test issue. In January 1992, a Pennsylvania superior
court declined to consider any foreign cases and instead relied solely
on the evidence presented at a Frye hearing in a lower court to
determine if any testimony related to the administration of the HGN
test was admissible. Commonwealth v. Apollo, 412 Pa. Super. 453,
455, 603 A.2d 1023, 1025 (1992). In Apollo, the prosecution
presented testimony from an optometrist who conducted his own
study of the incidence of HGN in sober persons, and stated that he
was “aware of no studies evaluating the reliability of the HGN test
that have reached any conclusion other than that it is the most
accurate field sobriety test available.” Apollo, 412 Pa. Super. at 460,
603 A.2d at 1027. The defense countered this testimony with technical
writings that criticized the HGN test and concluded that “the reliability
of the Horizontal Gaze Nystagmus test is not a settled proposition
within the scientific community.” Apollo, 412 Pa. Super. at 461, 603

4
The issue came before us once again in People v. Robinson, 223 Ill. 2d
165 (2006), but we declined to resolve the HGN issue, holding that the
question was waived because it “was not raised in [the defendant’s] posttrial
motion, his appeal before the appellate court, or his petition for leave to
appeal to this court.” Robinson, 223 Ill. 2d at 173-74.

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A.2d at 1027. The lower court then concluded that the HGN test was
an appropriate field test for sobriety, but that the general acceptance
of the HGN test was not sufficiently established. Apollo, 412 Pa.
Super. at 461, 603 A.2d at 1027. The Apollo court affirmed the lower
court’s preclusion of the HGN evidence, holding that the
optometrist’s testimony “fell short of establishing the ‘general
acceptance in the scientific community standard’ ” because it “was
largely based on his own personal views and observations.” Apollo,
412 Pa. Super. at 461, 603 A.2d at 1028.
In July 1992, the Kansas Supreme Court issued Witte, the leading
case against admitting the evidence produced by HGN testing without
a Frye hearing. After examining the holding in Blake, which was relied
upon by the prosecution, the Witte court presented its own research:
“Our research indicates that the reaction within the
scientific community is mixed. Some articles endorse the HGN
testing and its accuracy. See, e.g., Good & Augsburger, Use
of Horizontal Gaze Nystagmus as a Part of Roadside Sobriety
Testing, 63 Am. J. of Optometry & Physiological Optics 467
(1986). Other articles discuss concerns with the HGN test.
See, e.g., Carper & McCamey, 77 Ill. B.J. at 149; Halperin &
Yolton, Is the Driver Drunk? Ocularmotor Sobriety Testing,
57 J. of the Am. Optometric A. 654, 657 (1986). Several
commentators disagree with the Arizona Supreme Court’s
conclusions, insisting the HGN test has not been accepted
generally within the scientific community and questioning the
methodology of the NHTSA’s research. See, e.g., Cowan &
Jaffee, Proof and Disproof of Alcohol-Induced Driving
Impairment Through Evidence of Observable Intoxication
and Coordination Testing, 9 Am. Jur. Proof of Facts 3d 459
§12 (1990); Pangman, Horizontal Gaze Nystagmus: Voodoo
Science, 2 DWI Journal 1, 3-4 (1987); Rouleau, Unreliability
of the Horizontal Gaze Nystagmus Test, 4 Am. Jur. Proof of
Facts 3d 439 §7, p. 452 (1989); 1 Erwin, Defense of Drunk
Driving Cases §§ 8A:06, 8A:08 (3d ed. 1992); 2 Nichols,
Drinking/Driving Litigation §26:01 (1991 & 1992 Supp.).
These articles or the particular sections cited are not listed in
the Arizona opinion’s appendices. Most of these articles were

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 published after the Arizona opinion was issued April 7, 1986.”
Witte, 251 Kan. at 326-27, 836 P.2d at 1119.
The Witte court then noted that there was disagreement in the
scientific community about the correlation between the blood-alcohol
level and the angle of onset at which nystagmus occurs, that the
NHTSA has admitted that the 45-degree angle test is wrong 22% of
the time, and that the NHTSA study has been criticized for
deliberately screening out people at high risk for being classified as
false positives. Witte, 251 Kan. at 327-28, 836 P.2d at 1119, citing
Pangman, 2 DWI Journal, at 2 (citing J. Toglia,
Electronystagmography: Technical Aspects and Atlas (1976); Aschan,
Different Types of Alcohol Nystagmus, Acta Oto-Laryngologica
Supp. 140:69 (1957); Aschan, Bergstedt, Goldberg & Laurell,
Positional Nystagmus in Man During and After Alcohol Intoxication,
17 Q.J. of Studies on Alcohol 381 (1956); Lehti, The Effect of Blood
Alcohol Concentration on the Onset of Gaze Nystagmus, 13
Blutalkohol 411 (1976)). See M. Rouleau, 4 Am. Jur. Proof of Facts
3d 439 §§7, 8 (1989); 2 D. Nichols, Drinking/Driving Litigation
§26:01 (1989).
The Witte court continued,
“In addition to intoxication, many other factors can cause
nystagmus. ‘Nystagmus can be caused by problems in an
individual’s inner ear labyrinth. In fact, irrigating the ears with
warm or cold water, not a far-fetched scenario under
particular weather conditions, is a source of error.
Physiological problems such as certain kinds of diseases may
also result in gaze nystagmus. Influenza, streptococcus
infections, vertigo, measles, syphilis, arteriosclerosis, 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

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 consumption.’ Pangman, 2 DWI Journal at 3.” Witte, 251
Kan. at 328, 836 P.2d at 1120.
Witte cited more criticism of the studies that lauded the HGN test
and concluded,
“If the Arizona Supreme Court had had this evidence
before it, it may not have held that HGN evidence satisfies the
Frye admissibility requirements. The reliability of the HGN
test is not currently a settled proposition in the scientific
community. This court holds that HGN evidence requires a
Frye foundation for admissibility. If the Frye foundation is
established to this court’s satisfaction, HGN evidence will be
admitted in other cases without the need to satisfy the Frye
test each time. Before this court rules on whether HGN
evidence satisfies the Frye admissibility requirements, a trial
court first should have an opportunity to examine, weigh, and
decide disputed facts to determine whether the test is
sufficiently reliable to be admissible for any purpose in
Kansas.” Witte, 251 Kan. at 329-30, 836 P.2d at 1121.
After publication of Witte in 1992, courts have been reluctant to
take judicial notice of the general acceptance of the reliability of the
HGN test as an indicator of alcohol impairment based on the
reasoning of prior judicial decisions. In fact, a majority of courts since
1992 have resolved the HGN evidence issue only after at least a
partial Frye hearing occured in their jurisdiction. As discussed above,
Kirk joined with this majority in 1997 and called for a full Frye
hearing in Illinois to decide the matter.
Five states have conducted full Frye hearings on HGN testing
since 1992, with varying results. Ballard v. State, 955 P.2d 931
(Alaska App. 1998) (HGN test results admissible only to show that
person has consumed alcohol and is potentially impaired)5; People v.
Joehnk, 35 Cal. App. 4th 1488, 1507-08, 42 Cal. Rptr. 2d 6, 17
(1995) (HGN test is generally accepted as a useful tool “when
combined with other tests and observations in reaching an opinion
whether a defendant was intoxicated”), State v. Chastain, 265 Kan.

5
Alaska has since abandoned Frye and adopted Daubert.

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16, 960 P.2d 756 (1998) (HGN testing has not been generally
accepted within the scientific community); State v. Klawitter, 518
N.W.2d 577 (Minn. 1994) (HGN testing satisfies Frye); State v.
Baity, 140 Wash. 2d 1, 991 P.2d 1151 (2000) (the forensic application
of HGN to determining intoxication satisfies Frye).
In four other states, the type of hearing on the HGN issue was
similar to that which occured in Blake. In these states, the trial court
heard testimony from only the prosecutor before finding that HGN
evidence satisfied Frye. State v. Hill, 865 S.W.2d 702 (Mo. App.
1993) (when properly administered by adequately trained personnel,
the HGN test is admissible as evidence of intoxication), overruled on
other grounds, State v. Carson, 941 S.W.2d 518 (Mo. 1997); State v.
Baue, 258 Neb. 968, 607 N.W.2d 191 (2000) (HGN test results are
“admissible for the limited purpose of establishing that a person has an
impairment which may be caused by alcohol”); People v.
Vanderlofske, 186 Misc. 2d 182, 717 N.Y.S.2d 450 (Co. Ct. 2000)
(HGN test results are generally accepted in the scientific community
as a reliable indicator of intoxication)6; Yell, 856 P.2d at 999 (HGN
evidence is subject to Frye testing, but testimony from an arresting
officer alone is insufficient to establish general acceptance).7
Since 1992, only five states have made their determinations
regarding the admissibility of HGN evidence without the benefit of a
Frye hearing. Three of these states took judicial notice of the general
acceptance of HGN evidence, based primarily on the reasoning
presented in Blake. See Hawkins v. State, 223 Ga. App. 34, 476
S.E.2d 803 (1996); Schultz v. State, 106 Md. App. 145, 664 A.2d 60
(1995); Berger (all finding that HGN evidence satisfies the Frye
standard). The other two states, however, declined to take judicial
notice of the general acceptance of HGN evidence, and consequently
ruled it inadmissible.

6
Dr. Burns testified for the prosecution in six of the seven cases just
mentioned.
7
Oklahoma has since abandoned Frye and adopted Daubert.

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 In Young v. City of Brookhaven, 693 So. 2d 1355 (Miss. 1997),
the Mississippi Supreme Court held, without elaboration, that the
HGN test is not generally accepted within the scientific community
and its results cannot be used as scientific evidence to prove
intoxication or as a mere showing of impairment. Young, 693 So. 2d
at 1360-61. In State v. Doriguzzi, 334 N.J. Super. 530, 760 A.2d 336
(2000), the most recent appellate case on the matter, the Superior
Court of New Jersey held that it would not determine the general
acceptance of HGN evidence based upon its independent review of
authoritative, scientific and legal writings as well as opinions from
foreign jurisdictions. Doriguzzi, 334 N.J. Super. at 533, 760 A.2d at
337. The Doriguzzi court expressed its reasoning as follows,
“While it may very well be that HGN testing can meet the
Frye test, we believe that the case which decides the issue for
all other cases in New Jersey should be grounded in sufficient
expert testimony to assure defendants and the State alike that
a conviction for driving under the influence, when based in
part on HGN testing, is a conviction grounded in reliable
scientific data.” Doriguzzi, 334 N.J. Super. at 540, 760 A.2d
at 342.
As our research indicates, determinations on HGN testing are as
varied as the states that have made them. These disparate opinions
provide insight as to how HGN testing has been addressed, but do not
present the kind of unequivocal or undisputed viewpoint on the issue
upon which a court can take judicial notice. As such, we cannot take
judicial notice of the general acceptance of HGN test results based on
prior judicial decisions.

B. Technical Writings
The State contends that, even if we decline to take judicial notice
of the general acceptance of the HGN test as a reliable indicator of
alcohol impairment based on the reasoning of prior judicial decisions,
we should do so based on the technical writings on the subject. The
State makes this argument in light of our ruling on the standard of
review of Frye cases in In re Commitment of Simons, wherein we held
that, in reviewing a trial court’s Frye analysis, we may consider not

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only the record, but also “sources outside the record, including legal
and scientific articles, as well as court opinions from other
jurisdictions.” In re Commitment of Simons, 213 Ill. 2d at 531.
The State supports its argument with a battery of materials
endorsing the use of HGN testing as a reliable indicator of alcohol
impairment, including a 1993 resolution of the American Optometric
Association that declared the HGN test “to be a scientifically valid and
reliable tool for trained police officers to use in field sobriety testing.”
A sampling of the other articles presented by the State includes G.
Good & A. Augsberger, Use of Horizontal Gaze Nystagmus As a Part
of Roadside Sobriety Testing, 63 Am. J. of Optometry &
Physiological Optics 467 (1986); E. Halperin & R. Yolton, Is the
Driver Drunk? Oculomotor Sobriety Testing, 57 J. Am. Optometric
Ass’n 654 (September 1986); Horizontal Gaze Nystagmus: The
Science and the Law, American Prosecutors Research Institute,
National Traffic Law Center (1999).
Many of the articles offered by the State merely acknowledge the
accepted theory that there is a causal connection between HGN and
alcohol consumption, which defendant concedes. Several articles do
conclude that HGN test results are reliable indicators of alcohol
impairment, but at least one of the sources the State provides in the
appendix to its brief actually denounces the use of HGN testing for
roadside sobriety tests:
“Unfortunately, that alcohol can produce horizontal gaze-
evoked nystagmus has led to a ‘roadside sobriety’ test
conducted by law-enforcement officers. Nystagmus as an
indicator of alcohol intoxication is fraught with extraordinary
pitfalls: many normal individuals have physiologic end-point
nystagmus; small doses of tranquilizers that wouldn’t interfere
with driving ability can also produce nystagmus; nystagmus
may be congenital or consequent to structural neurologic
disease, and often a neuro-ophthalmologist or sophisticated
oculographer is required to determine whether nystagmus is
pathologic. Such judgments are difficult for experts to make
under the best conditions and impossible to make accurately
under roadside conditions. It is unreasonable to have cursorily
trained law officers using the test, no matter how intelligent,

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 perceptive, and well meaning they might be.” L. Dell’Osso &
R. Daroff, Nystagmus and Saccadic Intrusions and
Oscillations, at 26-27, in 2 Duane’s Clinical Opthamology, ch.
11 (2005).
In support of her argument, defendant presents an extensive list of
articles that condemn the reliability of HGN testing. The gist of most
of these writings is that the HGN test is too delicate a test to be
administered and interpreted accurately by police officers outside of
a laboratory, and that positive test results can be caused by many
other factors besides alcohol. See, e.g., W. Pangman, Horizontal Gaze
Nystagmus: Voodoo Science, 2 DWI J. 1 (1987); N. Willey, Feature:
Should HGN in OUI by DOA?, 13 Me. B.J. 60 (1998); J. Booker,
End-position Nystagmus as an Indicator of Ethanol Intoxication, 41
Science & Justice 113 (2001); J. Mancke, DUI Field Sobriety Tests:
Have the Courts Missed a Step?, 73 Pa. B. Ass’n Q. 117 (2002); S.
Rubenzer, The Psychometrics and Science of the Standardized Field
Sobriety Tests, 27 The Champion 40 (June 2003); J. Booker, The
Horizontal Gaze Nystagmus Test: Fraudulent Science in the
American Courts, 44 Science & Justice 133 (2004); M. Coffey, DWI–
Modern Day Salem Witch Hunts, The Champion, 51 (November
2004).
Defendant also argues that the HGN test was not developed to
measure whether a subject was impaired, and that it is being
improperly used for that purpose today. Defendant maintains that,
during an evidentiary hearing in New Mexico, Dr. Burns, who has
testified at almost every Frye hearing on HGN testing around the
nation, has referred to “the incorrect assumption that field sobriety
tests are designed to measure driving impairment,” and that, when
developing the HGN test, the NHTSA “pursued the development of
tests that would provide statistically valid and reliable indications of
a driver’s BAC, rather than indications of driving impairment.”
(Emphasis omitted.) State v. Lasworth, 131 N.M. 739, 742-43, 42
P.3d 844, 847 (2001). Defendant also contends that Dr. Burns has
written that “[t]he only appropriate criterion measure to assess the
accuracy of the SFSTs (standard field-sobriety tests) is BAC.
Measures of impairment are irrelevant because performance of the
SFSTs must be correlated with BAC level, rather than driving

-24-
performance.” Lasworth, 131 N.M. at 742, 42 P.3d at 847, quoting J.
Stuster & M. Burns, Validation of the Standardized Field Sobriety
Test Battery of BAC’s below 0.10 Percent, Final Report, Submitted
to the US Dept. of Transportation, NHTSA, at 10 (1998).
The fact that the HGN test was developed to measure blood-
alcohol content, but is not used for that purpose but, rather, used as
an indicator of impairment, has led one commentator to note, “This
leads to an apparent contradiction, in that the courts will not accept
the SFSTs for the purpose for which they were developed and the
method by which they were validated, but will accept them for
purposes for which they have not been directly studied or validated.”
H. Cohen, 10 Defense of Drunk Driving Cases: Criminal, Civil
§10.09, at 6 (2006). Defendant argues that such a contradiction calls
into serious question the conclusions reached in Blake, and relied
upon by Buening and Wiebler.
As illustrated by these conflicting materials, HGN testing appears
to have as many critics as it does champions. The technical writings
above reveal a dichotomy in the scientific community, rather than the
unequivocal or undisputed viewpoint necessary for us to take judicial
notice. As such, we cannot take judicial notice of the general
acceptance of the HGN test as a reliable indicator of alcohol
impairment based on these technical writings.
Our holding today does not purport to decide whether the HGN
test has been generally accepted as a reliable indicator of alcohol
impairment. Rather, we find that this issue cannot be resolved in
Illinois on judicial notice alone. In light of the disparate resolutions of
the issue in foreign jurisdictions, the varying opinions expressed in
articles on the subject, the fact that a Frye hearing has never been held
on the matter in Illinois, and the fact that, as far as we are aware, the
last Frye hearing held on this controversial methodology was held in
Washington in 2000, we hold that a Frye hearing must be held to
determine if the HGN test has been generally accepted as a reliable
indicator of alcohol impairment.

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 IV. Harmless Error
The State argues that, even if the trial court erroneously admitted
the HGN test results, the additional evidence against defendant
renders any such error harmless. Defendant maintains that the
admission of the HGN test results was not harmless because there was
no witness testimony that she was actually speeding or driving
erratically prior to the accident; no other field-sobriety tests were
conducted upon her; the chemical samples collected from her were
negative; the odor of beer on her breath indicated only consumption
of alcohol, and not impairment; and that the appearance of her eyes
could be attributed to her recent overnight shift in a chemical plant.
When a defendant challenges the admission of evidence, we may
hold the admission to be harmless “[w]hen the competent evidence in
the record establishes the defendant’s guilt beyond a reasonable doubt
and it can be concluded that retrial without the erroneous admission
of the challenged evidence would produce no different result.” People
v. Arman, 131 Ill. 2d 115, 124 (1989). Given the fact that defendant’s
blood-alcohol content was not verified by any chemical test, and no
other field-sobriety tests were given, it is reasonable to conclude that
the trial court relied heavily on the improperly admitted HGN test
results. Therefore, we cannot say that “retrial without the erroneous
admission of the challenged evidence would produce no different
result.” For this reason we hold that the admission of the HGN test
results was not a harmless error.

CONCLUSION
For the foregoing reasons, we retain jurisdiction and remand this
cause to the circuit court of Peoria County for a Frye hearing to
determine whether the HGN test has been generally accepted as a
reliable indicator of alcohol impairment. See People v. Wheeler, 334
Ill. App. 3d 273, 283 (2002) (a reviewing court retains jurisdiction of
any cause remanded to the circuit court for a Frye hearing). The
circuit court is directed to make appropriate findings of fact and
conclusions of law as to this question. The circuit court’s decision,
together with a record of the proceedings on remand, shall be filed

-26-
with the clerk of this court within 90 days of the date that this decision
becomes final.

Cause remanded with directions.

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