Reset A A Font size: Print

Court of Appeal, Fourth District, Division 3, California.

The PEOPLE of the State of California, Plaintiff and Respondent, v. William Michael LEAHY, Defendant and Appellant.

The PEOPLE of the State of California, Plaintiff and Respondent, v. Michael Norman TATAR, Defendant and Appellant.

No. G013782.

Decided: August 24, 1993

Ronald Y. Butler, Public Defender, Carl C. Holmes, Chief Deputy Public Defender, Thomas Havlena and Alan J. Crivaro, Deputy Public Defenders, for defendants and appellants. Michael R. Capizzi, Dist. Atty., Maurice L. Evans, Chief Asst. Dist. Atty., Wallace J. Wade, Asst. Dist. Atty., Kathleen M. Harper and Donald Clarence, Deputy Dist. Attys., for plaintiff and respondent.

 We accepted transfer of these consolidated appeals 1 from the appellate department of the Orange County Superior Court to consider whether a police officer without scientific expertise is qualified to give an opinion concerning the results of a horizontal gaze nystagmus (HGN) field sobriety test 2 and whether HGN evidence is admissible at all in the absence of a Kelly–Frye foundation (People v. Kelly (1976) 17 Cal.3d 24, 130 Cal.Rptr. 144, 549 P.2d 1240;  Frye v. United States (D.C.Cir.1923) 293 F. 1013).   We answer both questions in the negative.


William Michael Leahy was stopped after a police officer observed him driving 55 miles per hour in a 25–mile–per–hour zone.   His face was flushed, his eyes were red and watery, his speech was slurred, his balance was unsteady, and his person exuded the odor of alcohol.   Despite these relatively conventional indicia of intoxication, the officer was not convinced Leahy was under the influence of alcohol.   And apparently with reason, for defendant passed two field sobriety tests, the “internal clock” test and the alphabet test.   The officer did not believe Leahy successfully completed the horizontal gaze nystagmus test (HGN), however;  and he was arrested.   A subsequent intoxilyzer breath test revealed a .10 blood alcohol level.

In a wholly separate incident, Michael Norman Tatar was stopped after he sped off a freeway exit, skidded through a red light, and came to rest in the middle of an intersection.   Unfortunately for Tatar, he performed these maneuvers in full view of an officer standing at a corner while his partner wrote a ticket for another traffic offender.

Tatar also displayed the usual physical symptoms of intoxication:  He had trouble standing up and failed six field sobriety tests, including the HGN test.   He eventually admitted consuming five beers.   His blood alcohol level turned out to be .17.

Leahy and Tatar were charged in independent proceedings in different municipal court districts with driving under the influence of alcohol (Veh.Code, § 23152, subd. (a)) and driving with a blood alcohol level in excess of .08 (Veh.Code, § 23152, subd. (b)).  Each made an in limine motion to bar evidence of the HGN test based on People v. Kelly, supra, 17 Cal.3d 24, 130 Cal.Rptr. 144, 549 P.2d 1240 and Frye v. United States, supra, 293 F. 1013.   The motions were denied.

In both prosecutions the arresting officers were permitted to testify over continuing objections concerning the relationship between the HGN test and defendants' intoxication.   In Tatar's case the court (Singer, J.) said the officer was testifying as a lay witness.3  Leahy's judge (McKone, J.) made a similar determination:  “[T]he Kelly–Frye rule is inapplicable because the nature of this test isn't a specific test for the determination of alcohol;  it is only a symptom that the officer is testifying to ․ in the same manner as he might be testifying to a symptom of slurred speech or a person's face turning red, or ․ bloodshot eyes.   It would be on that type of reasoning that it would be allowed in.”   Leahy and Tatar were each convicted on both counts.


The Kelly–Frye rule is this:  “[W]hile courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.” 4  (Frye v. United States, supra, 293 F. 1013, 1014;  see People v. Kelly, supra, 17 Cal.3d at p. 30, 130 Cal.Rptr. 144, 549 P.2d 1240.)   That is the major premise.   The minor premise is that a lay witness is not competent to prove the validity of a scientific principle, despite a complete familiarity with its application.  (See People v. Kelly, supra, at p. 39, 130 Cal.Rptr. 144, 549 P.2d 1240.)   In the few cases to consider the HGN test, the focus has usually been on the minor premise;  we will look at both.

There are three pertinent decisions dealing with HGN, two Court of Appeal opinions (People v. Williams (1992) 3 Cal.App.4th 1326, 5 Cal.Rptr.2d 130;   People v. Ojeda, supra, 225 Cal.App.3d 404, 275 Cal.Rptr. 472) and one from an appellate department (People v. Loomis (1984) 156 Cal.App.3d Supp. 1, 203 Cal.Rptr. 767).   We examine them in turn.

In Loomis the testifying officer explained his experience in administering the HGN test and then calculating the suspect's blood alcohol levels based on the results.   He tested Loomis, noted a ratio of less than 20°, and determined defendant's blood alcohol level was between .15 and .16.   The San Diego Superior Court Appellate Department concluded the trial court erroneously permitted the officer to relate a lay opinion as to defendant's blood alcohol level based on the HGN test:  “In the present case the officer testified to the oscillation of the driver's pupil at a certain angle.   That is certainly something he could have perceived.   What is not based on his perception, however, is the officer's opinion that such oscillation at that angle indicates a blood alcohol level of [a certain] percent.   That conclusion could not possibly be based on the officer's own perceptions and could be admitted only if the evidence is admissible as expert testimony.”  (Id. at pp. 5–6, 203 Cal.Rptr. 767.)

Citing Kelly and Frye, the appellate department then squelched the notion that the testimony could have qualified as expert opinion:  “[N]either the reliability of the method nor the qualification of the witness as an expert on the subject was established.   Since there is no indication of general acceptance in the scientific community of the [HGN] test as an indicator of blood alcohol level, the evidence should have been excluded.”  (Id. at p. 7, 203 Cal.Rptr. 767.)   How the court would have viewed the test as an “indicator” of intoxication had it merely been used as part of the basis of the officer's opinion of intoxication is not stated, but the conclusion should, and would presumably, have been the same.

Similarly, in People v. Ojeda, supra, 225 Cal.App.3d 404, 275 Cal.Rptr. 472, defendant unsuccessfully argued testimony by the arresting officer concerning the HGN test should be excluded because the deputy did not possess the “required scientific expertise.”   The trial court “agreed [the deputy] could not testify to a particular level of blood alcohol on the basis of the [HGN] test, and could not attempt to explain its physiological basis, but ruled he could testify that he observed the phenomenon in defendant and that he has frequently observed the same phenomenon in people known to be under the influence of alcohol.”  (Id. at p. 407, 275 Cal.Rptr. 472.)   That was the substance of the HGN testimony, and defendant was convicted of driving while under the influence of alcohol and with a blood alcohol level in excess of .10.

A majority of the appellate panel rejected Ojeda's challenge to the HGN test evidence;  but it refused to discuss “the Kelly/Frye problem,” noting defendant did not object on that basis in the trial court.5  (People v. Ojeda, supra, 225 Cal.App.3d at p. 407, 275 Cal.Rptr. 472.)   Instead, the majority analyzed “the correctness of the court's ruling allowing the deputy to draw an opinion as to defendant's intoxication based upon his own experience with the HGN test” (id. at p. 408, 275 Cal.Rptr. 472) and concluded there was no error:  “The observation of HGN in a person and its interpretation as an effect of alcohol intoxication do not necessarily require expertise in physiology, toxicology, or any other scientific field.   The nystagmus effect can be observed without mechanical, electronic or chemical equipment of any kind.   At least in the simple form presented in this case, it requires no more medical training than administration of the other field sobriety tests, such as the one-legged balance.  [¶] It is hardly surprising that police officers who deal daily with intoxicated persons become expert at recognizing the physical effects of intoxication, and that they learn to perceive effects somewhat more subtle than those apparent to the amateur.   This does not make them scientists․  [The officer] drew his generalization from experience, not from experimentation, and did not attempt to quantify the relationship he observed.” 6  (Ibid.)

The majority opinion ends with the following passage:  “We do not hold that HGN is a reliable indicator of alcohol intoxication, that the HGN test meets Kelly/Frye standards, or that nonscientists are qualified to correlate HGN with a particular level of blood alcohol.   Nor do we decide the extent of personal experience with a field sobriety test an officer must have in order to use it to form an opinion on intoxication.   We hold only that an officer with sufficient experience may testify, based on his or her own experience with the relationship between HGN and alcohol intoxication, to an opinion that a subject was or was not under the influence.” 7  (Id. at p. 409, 275 Cal.Rptr. 472.)   As noted earlier, this appears to have been the thinking of the trial judges who heard these cases, as well.

In People v. Williams, supra, 3 Cal.App.4th 1326, 5 Cal.Rptr.2d 130, after a hearing under Evidence Code section 402, the trial court permitted the arresting officer to offer a lay opinion based on a series of observations, including the HGN test, that defendant had imbibed alcohol.   In addition, a forensic alcohol analyst was allowed to testify concerning the proper administration of an HGN test and the various possible causes of nystagmus.8  After reversing the conviction on other grounds, the Court of Appeal concluded the trial judge also erred in admitting HGN test evidence.   This was not dicta because it was a direction to the trial court in the event of a retrial (Code Civ.Proc., § 43).

As in Ojeda, the Williams court declined to reach the Kelly–Frye issue.9  But the court disagreed with Ojeda as to whether a police officer could render a lay opinion that correlated the results of an HGN test and the subject's intoxication:  “Lay witnesses have been permitted to give an opinion of another's state of intoxication when based on the witness's personal observations of such commonly recognizable signs as an odor of alcohol, slurring of speech, unsteadiness, and the like.  [Citations.]   If [the officer's] opinion that [defendant] was under the influence of alcohol was based solely on such matters, it would be admissible as lay opinion.   Here, however, [the officer's] opinion was based in some part on his administration of HGN testing and his interpretation of appellant's response to the testing stimulus.   He drew a conclusion from the testing only because of his knowledge, training, and experience which was clearly beyond common experience.   Matters beyond common experience are not proper subjects of lay opinion testimony.  [Citation.]  ‘The HGN test is a different type of test from balancing on one leg or walking a straight line because it rests almost entirely upon an assertion of scientific legitimacy rather than a basis of common knowledge.   Different rules therefore apply to determine its admissibility.’  (State v. Superior Court (1986) 149 Ariz. 269 [718 P.2d 171].)”  (People v. Williams, supra, 3 Cal.App.4th at pp. 1332–1333, 5 Cal.Rptr.2d 130;  see Evid.Code, § 800.)

Having rejected the notion that a police officer can properly be allowed to offer lay testimony concerning the HGN test as an indicator of a subject's intoxication, the Williams panel then concluded an officer may not give expert opinion on the same topic either:  “We will assume [the officer's] training and experience qualified him as an expert to administer the nystagmus test and observe signs of nystagmus.   Being qualified to attribute the observed eye movements to a particular cause, however, is a far different matter․  [¶] [The officer's] opinion that [defendant] was under the influence of alcohol, to the extent it was based on the nystagmus test, rests on scientific premises well beyond his 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, [an officer's] opinion on causation, notwithstanding his ability to recognize the symptom, [will be] unfounded.   It should [be] excluded.”  (Id. at pp. 1333–1334, 5 Cal.Rptr.2d 130.)

Finally, Williams concluded the forensic alcohol expert's testimony was “not sufficiently factual to aid the jury in making a meaningful evaluation of [the arresting officer's] observations when he administered the test to [defendant].   At best it merely furnished a basis for the jury to speculate that [defendant's] nystagmus was caused by alcohol.”  (Id. at p. 1335, 5 Cal.Rptr.2d 130.)   We agree with Justice Haning and the Williams and Loomis courts.   It was error to admit HGN evidence as either lay or expert testimony without a proper scientific foundation.   The usual field sobriety tests are grounded in common knowledge, i.e., that intoxicated persons will often demonstrate lack of concentration, judgment, balance, and coordination.   HGN is not.

Consequently, at least as the law of California currently stands, it will be error in the event of any retrial to permit such evidence as the basis of an opinion concerning intoxication without a Kelly–Frye foundation, i.e., proof of general acceptance of HGN in the scientific community.10  (Code Civ.Proc., § 43.)  People v. Kelly, supra, 17 Cal.3d at pp. 31–32, 130 Cal.Rptr. 144, 549 P.2d 1240 explains why this must be the case:  “The primary advantage ․ of the Frye test lies in its essentially conservative nature.   For a variety of reasons, Frye was deliberately intended to interpose a substantial obstacle to the unrestrained admission of evidence based upon new scientific principles.  ‘There has always existed a considerable lag between advances and discoveries in scientific fields and their acceptance as evidence in a court proceeding.’  [Citation.]   Several reasons founded in logic and common sense support a posture of judicial caution in this area.   Lay jurors tend to give considerable weight to ‘scientific’ evidence when presented by ‘experts' with impressive credentials.   We have acknowledged the existence of a ‘․ misleading aura of certainty which often envelops a new scientific process, obscuring its currently experimental nature.’  [Citations.]”  (See also People v. Stoll (1989) 49 Cal.3d 1136, 1156, 265 Cal.Rptr. 111, 783 P.2d 698.)

 Thus, in the matters before us, we must hold the courts erred in permitting the officers to testify concerning HGN.   The error was clearly prejudicial in Leahy's case;  i.e., it is reasonably probable a different result would have been achieved on both counts but for the HGN evidence (People v. Watson (1956) 46 Cal.2d 818, 836, 299 P.2d 243):  Leahy passed the other field sobriety tests.   His blood alcohol level was said to be .10, only .02 over the statutory maximum;  and criminalists generally concede a margin of error of at least plus or minus .01.   Also, the passage of time between arrest and test can account for even more than that, up or down.   About 90 minutes went by between arrest and Leahy's encounter with the intoxilyzer.   Depending on when he had his last drink and a host of other factors, his blood alcohol level could have risen or fallen several points in that time.

 On the other hand, the error was unlikely to have prejudiced Tatar's case.   His driving strongly demonstrated impairment, and he displayed the usual physical signs of intoxication.   He failed all of the traditional field sobriety tests administered, admitted consumption of five beers, and had a blood alcohol level of .17, more than double the statutory limit.   The HGN evidence would only have been another drop in the bucket for his jury.   We find it improbable that Tatar would do better on retrial.

III **

The judgment is reversed as to William Michael Leahy (Muni.Ct. No. HBW209618P0) with directions to proceed in accordance with the views expressed above.   The judgment is affirmed in the case of Michael Norman Tatar (Muni.Ct. No. NS9103992).


1.   They arise from two unrelated municipal court prosecutions.   Different panels (with two common members) of the appellate department issued a joint opinion.   The matters appear here under one case number.

2.   The Court of Appeal has explained, “Nystagmus is an involuntary rapid movement of the eyeball, which may be horizontal, vertical, or rotatory.  [Citation.]   An inability of the eyes to maintain visual fixation as they are turned from side to side (in other words, jerking or bouncing) is known as horizontal gaze nystagmus, or HGN.  [Citation.]   Some investigators believe alcohol intoxication increases the frequency and amplitude of HGN and causes HGN to occur at a smaller angle of deviation from the forward direction.”  (People v. Ojeda (1990) 225 Cal.App.3d 404, 406, 275 Cal.Rptr. 472.)

3.   The district attorney insists in his brief that the officer testified as an expert.   The engrossed settled statement clearly states the contrary, however.   The focus of our opinion will be on expert testimony, though, for that is what the HGN evidence was.   As will be amplified below, it was improperly offered as the opinion of nonexperts.   Evidence Code section 800 provides, “If a witness is not testifying as an expert, his testimony in the form of an opinion is limited to such an opinion as is permitted by law, including but not limited to an opinion that is:  [¶] (a) Rationally based on the perception of the witness;  and [¶] (b) Helpful to a clear understanding of his testimony.”   An opinion concerning an individual's alleged state of intoxication cannot be “rationally based” on symptoms not commonly understood without presentation of a scientific foundation to the trier of fact.

4.   Several months ago the United States Supreme Court held Frye was superseded by the Federal Rules of Evidence (specifically, rule 702), where there is no requirement of general acceptance in the scientific community.  (Daubert v. Merrell Dow Pharmaceuticals 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469.)   But under federal law, if a witness qualifies as an expert, the court may not play censor.   The merits and demerits of a particular scientific test, approach, or procedure are simply matters for the jury to sort out.A comparison of the California Evidence Code with the Federal Rules reveals a strong similarity in this area.   Our code says nothing of “general acceptance in the scientific community.”  Evidence Code section 801, for example, merely requires expert opinion to “[r]elate[ ] to a subject that is sufficiently beyond common experience that the opinion of an expert would assist the trier of fact” and be “[b]ased on matter (including his special knowledge, skill, experience, training, and education) perceived by or personally known to the witness or made known to him ․ is of a type that reasonably may be relied upon by an expert in forming an opinion upon the subject to which his testimony relates, unless an expert is precluded by law from using such matter as a basis for his opinion.”   This last clause may have been intended to codify the Frye rule, but the Law Revision Commission comment does not so state and uses a different example to illustrate its application.In People v. Kelly, supra, 17 Cal.3d 24, 130 Cal.Rptr. 144, 549 P.2d 1240, the Supreme Court, while making a passing reference to Evidence Code section 801 (id. at p. 30, 130 Cal.Rptr. 144, 549 P.2d 1240), appears to embrace Frye based on case law.   Another way to reconcile section 801 with Kelly–Frye is to focus on the words “of a type that reasonably may be relied upon by an expert.”   Under Kelly–Frye only generally accepted science is considered reliable.Thus, there is reason to wonder whether Kelly, a unanimous decision of the California Supreme Court issued a decade after adoption of the Evidence Code, might be ripe for reexamination.   The civil defense bar, which has long decried “junk science,” will surely strongly resist any tampering with Kelly–Frye in California, while district attorneys can be expected to seek a change to the new federal rule.   None of this is our problem, of course;  we examine the issues in light of Kelly–Frye.

5.   The objection was to the lack of the deputy's scientific expertise and was enough, we think, to at least raise the minor premise of People v. Kelly, supra, 17 Cal.3d at p. 39, 130 Cal.Rptr. 144, 549 P.2d 1240:  “The record in the instant case reveals that Nash has an impressive list of credentials in the field of voiceprint analysis.   However, these qualifications are those of a technician and law enforcement officer, not a scientist.   Neither his training under Kersta, his association with the Tosi study, his limited college study in certain speech sciences, his membership in organizations promoting the use of voiceprints, nor his former position as head of the Michigan State Police Voice Identification Unit, necessarily qualifies Nash to express an informed opinion on the view of the scientific community toward voiceprint analysis.   This area may be one in which only another scientist, in regular communication with other colleagues in the field, is competent to express such an opinion.”

6.   Justice Haning disagreed with the majority, but found admission of the HGN evidence was harmless error.

7.   Justice Haning noted, “I submit that the HGN phenomenon is not sufficiently within common experience that it is readily understood or accepted as an indicator of intoxication․   Consequently, any explanation of the effects of alcohol on eye movement should be given only by an expert.”  (People v. Ojeda, supra, 225 Cal.App.3d at p. 410, 275 Cal.Rptr. 472 (conc. opn. of Haning, J.).)   He added, “I am puzzled by the majority's statement that ‘[w]e do not hold that HGN is a reliable indicator of alcohol intoxication [or] that the HGN test meets Kelly/ Frye standard ․,’ and yet they conclude that the untrained officer is qualified to render a scientific opinion to the contrary.   This analysis simply eludes me.   I find the rationale of People v. Loomis, supra, 156 Cal.App.3d Supp. 1 [203 Cal.Rptr. 767] more persuasive.”  (People v. Ojeda, 225 Cal.App.3d at p. 411, 275 Cal.Rptr. 472 (conc. opn. of Haning, J.).)We agree.   Would a high school teacher be permitted to testify based on years of classroom observation alone that acne is caused by overindulgence in candy?   Would an uneducated barber be qualified to state an opinion in court as to the causes of baldness?

8.   This expert conceded “that factors other than alcohol impairment may cause nystagmus.”  (Id. at p. 1331, 5 Cal.Rptr.2d 130.)   He cited fatigue, circadian rhythm, and antihistamines.  (See also Holmes v. Kizer (1992) 11 Cal.App.4th 395, 398, 13 Cal.Rptr.2d 746 [disease];  Emerick v. Raleigh Hills Hospital (1982) 133 Cal.App.3d 575, 583, 184 Cal.Rptr. 92 [alcohol addiction];  Humble v. Union Pacific R.R. Co. (1949) 90 Cal.App.2d 276, 278–279, 202 P.2d 791 [trauma].)  The expert admitted there has been little scientific research relating nystagmus to alcohol consumption and acknowledged no one knew “the exact mechanism by which alcohol might produce nystagmus.”  (People v. Williams, supra, 3 Cal.App.4th at p. 1331, 5 Cal.Rptr.2d 130.)

9.   The court noted that no California decision had yet determined whether the prosecution must first establish that the HGN test meets Kelly–Frye standards.   Because there was no effort in the first trial to qualify the HGN test under Kelly–Frye, the Williams panel refused to speculate on whether the prosecution would be required to do so on retrial.   This is a puzzler in an otherwise scholarly and well-reasoned opinion.   The court's analysis makes plain that HGN evidence will require a foundation in scientific testimony.   If that is not the same as saying Kelly–Frye must be applied to it, we must be missing something.Also, Code of Civil Procedure section 43 seemingly obliged the court to instruct the lower court on the matter:  “[I]f a new trial be granted [on appeal], the court shall pass upon and determine all the questions of law involved in the case, presented upon such appeal, and necessary to the final determination of the case.”

10.   The officers are qualified to testify as to their observations of the HGN tests as a foundation for interpretation by a scientist capable of explaining and validating the phenomena, but no more.   Even though police might be prepared to testify that they had seen identical bouncing eyeballs in thousands of persons arrested and convicted of driving under the influence, this would not prove the test result necessarily meant anything, for nystagmus appears naturally in some people (People v. Milham (1984) 159 Cal.App.3d 487, 496, 205 Cal.Rptr. 688) and may be induced by causes apart from alcohol intoxication in others.  (See fn. 8 above.)   Moreover, many suspects who passed the HGN test were presumably not arrested and thus not subjected to blood alcohol tests which might have shown they were nonetheless intoxicated.

FOOTNOTE.   See footnote *, ante.

CROSBY, Associate Justice.

SILLS, P.J., and SONENSHINE, J., concur.

Copied to clipboard