I N T H E S U P R E M E C O U R T O F T E N N E S S E E
A T N A S H V I L L E
( H E A R D A T C O O K E V I L L E )
S T A T E O F T E N N E S S E E , ) F O R P U B L I C A T I O N
)
) F I L E D : O C T O B E R 1 3 , 1 9 9 7
A p p e l l a n t )
) D A V I D S O N C O U N T Y
v . )
) H O N . W A L T E R C . K U R T Z ,
C O R A M U R P H Y , ) J U D G E
A p p e l l e e FILED )
) N O . 0 1 - S - 0 1 - 9 6 0 2 - C C - 0 0 0 3 5
October 13, 1997
Cecil W. Crowson
Appellate Court Clerk
F o r A p p e l l e e : F o r A p p e l l a n t :
J E F F E R S O N T . D O R S E Y J O H N K N O X W A L K U P
A s s i s t a n t P u b l i c D e f e n d e r A t t o r n e y G e n e r a l a n d R e p o r t e r
N a s h v i l l e , T N
M I C H A E L E . M O O R E
S o l i c i t o r G e n e r a l
W I L L I A M D A V I D B R I D G E R S
A s s i s t a n t A t t o r n e y G e n e r a l
N a s h v i l l e , T N
V I C T O R S . J O H N S O N , I I I
D i s t r i c t A t t o r n e y G e n e r a l
J A M E S D . S L E D G E
A s s i s t a n t D i s t r i c t A t t o r n e y
N a s h v i l l e , T N
O P I N I O N
C O U R T O F C R I M I N A L A P P E A L S A F F I R M E D B I R C H , J .
2
The Court of Criminal Appeals reversed the judgment of
the trial court that convicted Cora Murphy, the defendant, of
driving while under the influence of an intoxicant1 and remanded
the case for a new trial. We consider now the appeal of the State
of Tennessee,2 and we must determine whether testimony concerning
an Horizontal Gaze Nystagmus (“HGN”) sobriety test constitutes
“scientific, technical, or other specialized knowledge” under
Tenn. R. Evid. 702. We hold that the HGN test is a scientific
test. To be admissible at trial, such evidence must satisfy the
requirements of Tenn. R. Evid. 702 and 703 as announced in McDaniel
v. CSX Transportation, Inc., S.W.2d (Tenn 1997). Because
we are unable to determine from the record now before us whether
these admissibility requirements have been met, the judgment of the
Court of Criminal Appeals is affirmed, and we remand this case to
the trial court for a new trial.
I
Murphy was arrested and charged with driving while under
the influence of an intoxicant on May 31, 1993. At trial, the
State relied primarily on the results of an HGN sobriety test.
Michael Eby, the arresting officer, described the test he
administered to Murphy and his conclusions therefrom as follows:
1
Tenn. Code Ann. § 55-10-401.
2
Oral argument was heard in this case on October 8, 1996, in
Cookeville, Putnam County, Tennessee, as part of this Court’s
S.C.A.L.E.S. (Supreme Court Advancing Legal Education for Students)
project.
3
[The HGN test] works on the
movement of the eyes, that --- what
you check for are three different
things. One, you check for smooth
movement. You have them follow an
object, either a pen, tip of a pen
or your finger, and they’re supposed
to follow with their eyes. And if
there’s nystagmus present, their
eyes will not move from side to side
smoothly; they will have jumping
movements in them.
Then you check for, at maximum
deviation, any signs of movement.
And what it is is [sic] when you get
to a 45 degree angle, their eyes
will jerk back and forth if there’s
signs of nystagmus there.
And the last one is you check
for the offset [sic, onset] of it
before 45 degrees.
. . . .
on all three points both the eyes
[Murphy] had obvious signs of
nystagmus.
Murphy was tested as she faced the flashing lights of
Eby’s patrol car. At trial, Eby acknowledged that nystagmus may be
caused by many factors other than alcohol consumption. Eby did not
conduct any other field sobriety tests, nor was Murphy’s blood or
breath later analyzed for alcohol content. Eby also testified
concerning his general observations of Murphy made during the
incident. As stated, the trial court held that the HGN test
results did not constitute scientific evidence. The Court of
Criminal Appeals reversed.
4
II
Nystagmus is an involuntary jerking movement of the eye
either as it attempts to focus on a fixed point or as it moves to
one side. The phenomenon results from the body’s attempt to
maintain orientation and balance. State v. Cissne, 72 Wash. App.
677, 865 P.2d 564, 566 (1994). “The theory behind the [HGN] test
is that there is a strong correlation between the amount of alcohol
a person consumes and the angle of onset of the nystagmus.” State
v. Witte, 251 Kan. 313, 836 P.2d 1110, 1112 (1992)(quoting Carper
& McCamey, Gaze Nystagmus: Scientific Proof of DUI?, 77 Ill.B.J.
146, 147 (1988)).
The effect of alcohol consumption on nystagmus may be
observed in three ways:
“Angle of Onset--the more
intoxicated a person becomes, the
sooner the jerking will occur as the
eyes move to the side.
“Maximum Deviation--the greater the
alcohol impairment the more distinct
the nystagmus is when the eyes are
as far to the side as possible.
“Smooth Pursuit--an intoxicated
person often cannot follow a slowly
moving object smoothly with his
eyes.” 2 Nichols, Drinking/Driving
Litigation §26:01, p. 159 (1992
Supp.)
Id. at 1113.
In conducting an HGN test, the subject should be
instructed to keep the head still and with one eye covered, follow
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a penlight or other object with the uncovered eye. The penlight is
held at eye level about 12 to 15 inches from the subject’s head.
It is then moved from directly in front of the subject’s eyes to
one side. As a person who has been consuming alcohol attempts to
follow the penlight’s movement, so the theory goes, nystagmus will
occur sooner and be more pronounced than it would be in a person
who has not consumed any alcohol.
The State argues, and certain other jurisdictions have
accepted this reasoning,3 that HGN testing is not scientific
because it simply involves an officer’s objective observations of
the subject’s physical characteristics. In this way, says the
State, HGN is no different from other field sobriety tests.4
In our view, the HGN test does differ fundamentally from
other field sobriety tests because the witness must necessarily
explain the underlying scientific basis of the test in order for
the testimony to be meaningful to a jury. Other tests, in marked
contrast, carry no such requirement. For example, if a police
3
Whitson v. State, 314 Ark. 458, 863 S.W.2d 794 (1993); State
v. Murphy, 451 N.W.2d 154 (Iowa 1990); State v. Garris, 603 So.2d
277 (La. App. 2 Cir. 1992); City of Fargo v. McLaughlin, 512 N.W.2d
700 (N.D. 1994); State v. Nagel, 30 Ohio App.3d 80, 506 N.E.2d 285
(1986); State v. Sullivan, 426 S.E.2d 766 (S.C. 1993).
4
In State v. Gilbert, 751 S.W.2d 454, 459 (Tenn. Crim. App.
1988), the Court of Criminal Appeals held that field sobriety tests
were not “scientific” and therefore, not subject to Tenn. R. Evid.
702. However, the intermediate court did not specify which field
sobriety tests were utilized in that case. There are several
unpublished opinions by the Court of Criminal Appeals that have
held that HGN test results are not scientific in nature. As author
of this opinion, I acknowledge that I participated in several of
those opinions while on the lower court and even authored one.
After further reflection, however, I have concluded that the course
we adopt today is the better-reasoned one.
6
officer testifies that the defendant was unable to walk a straight
line or stand on one foot or count backwards, a jury needs no
further explanation of why such testimony is relevant to or
probative on the issue of the defendant’s condition. A juror can
rely upon his or her personal experience or otherwise obtained
knowledge of the effects of alcohol upon one’s motor and mental
skills to evaluate and weigh the officer’s testimony. However, if
a police officer testifies that the defendant exhibited nystagmus,
that testimony has no significance to the average juror without an
additional explanation of the scientific correlation between
alcohol consumption and nystagmus. In effect, the juror must rely
upon the specialized knowledge of the testifying witness and likely
has no independent knowledge with which to evaluate the witness’s
testimony.
And there is another distinction between the HGN test and
other field sobriety tests, and it concerns measurement. Returning
to examples, an officer may testify that the subject performed the
“finger to nose” test successfully three out of seven attempts.
Once again, no explanation is needed. In contrast, when an officer
testifies that the subject’s eye movement was rapid and very jerky
at less than a 40 degree angle, that officer is testifying about a
measurement that probably should be taken with a measuring device.
Therefore, the accuracy of this testimony may be questionable in
light of the officer’s non-scientific measurement of a
scientifically measurable phenomenon.
7
In Witte, the Kansas Supreme Court cogently summarized
the distinction between the HGN test and other field sobriety
tests:
The HGN test is distinguished from
other field sobriety tests in that
science, rather than common
knowledge, provides the legitimacy
for HGN testing. . . . HGN test
results are “scientific evidence
based on the scientific principle
that consumption of alcohol causes
the type of nystagmus measured by
the HGN test.” . . .
[T]he officer’s opinion that the
defendant “was under the influence
of alcohol, to the extent it was
based on the nystagmus test, rests
on scientific premises well beyond
[the officer’s] knowledge, training,
or education. Without some
understanding of the processes by
which alcohol ingestion produces
nystagmus, how strong the
correlation is, how other possible
causes might be masked, what margin
of error has been shown in
statistical surveys, and a host of
other relevant factors, [the
officer’s] opinion on causation,
notwithstanding his ability to
recognize the symptom, was
unfounded.”
Witte, 836 P.2d at 1115-16 (quoting Commonwealth v. Miller, 367 Pa.
Super. 359, 365, 532 A.2d 1186 (1987) and People v. Williams, 3
Cal. App. 4th 1326, 1334, 5 Cal. Rptr. 2d 130 (1992)).
Tennessee Rule of Evidence 702 states:
If scientific, technical, or other
specialized knowledge will
substantially assist the trier of
fact to understand the evidence or
to determine a fact in issue, a
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witness qualified as an expert by
knowledge, skill, experience,
training, or education may testify
in the form of an opinion or
otherwise.5
In Tennessee, evidence constitutes “scientific, technical, or other
specialized knowledge” if it concerns a matter that “the average
juror would not know, as a matter of course. . . .” State v.
Bolin, 922 S.W.2d 870, 874 (Tenn. 1996). In our view, the average
juror would not know, as a matter of course, that a correlation
exists between alcohol consumption and nystagmus. Consequently,
testimony concerning the HGN field sobriety test constitutes
“scientific, technical, or other specialized knowledge.”6 As such,
it must be offered through an expert witness and must meet the
requirements of Tenn. R. Evid. 702 and 703 as explained in McDaniel
v. CSX Transportation, S.W.2d (Tenn 1997).
The judgment of the Court of Criminal Appeals is
affirmed, and the cause is remanded to the trial court for a new
trial. Costs are taxed to the State for which execution may issue,
if necessary.
________________________________________
ADOLPHO A. BIRCH, JR., Justice
CONCUR:
Anderson, C.J.
Drowota, Reid, JJ.
O’Brien, S.J.
5
Tennessee Rule of Evidence 702 requires that the evidence
“substantially” assist the trier of fact; in contrast, the federal
rule simply requires that the evidence assist the trier of fact.
6
An apparent majority of the jurisdictions that have addressed
this issue agree with our conclusion. See State v. Merritt, 36
Conn. App. 76, 647 A.2d 1021, 1026 (1994) and the authorities cited
therein.
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