v. Marston , 2020 COA 121 ( 2020 )


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  •      The summaries of the Colorado Court of Appeals published opinions
    constitute no part of the opinion of the division but have been prepared by
    the division for the convenience of the reader. The summaries may not be
    cited or relied upon as they are not the official language of the division.
    Any discrepancy between the language in the summary and in the opinion
    should be resolved in favor of the language in the opinion.
    SUMMARY
    August 6, 2020
    2020COA121
    No. 18CA1879, People v. Marston — Crimes — DWAI;
    Evidence — Admissibility
    A division of the court of appeals holds that a trial court may
    admit evidence of the results of a horizontal gaze nystagmus (HGN)
    test given to a motorist first without holding a Shreck hearing, if the
    evidence is offered only as evidence of impairment and if the
    witness testifying about the administration and the results of the
    test is competent to give such testimony.
    COLORADO COURT OF APPEALS                                            2020COA121
    Court of Appeals No. 18CA1879
    Jefferson County District Court No. 16CR2934
    Honorable Tamara S. Russell, Judge
    The People of the State of Colorado,
    Plaintiff-Appellee,
    v.
    Shawn Patrick Marston,
    Defendant-Appellant.
    JUDGMENT AFFIRMED
    Division V
    Opinion by JUDGE J. JONES
    Gomez, J., concurs
    Welling, J., concurs in part and dissents in part
    Announced August 6, 2020
    Philip J. Weiser, Attorney General, Frank R. Lawson, Assistant Attorney
    General, Denver, Colorado, for Plaintiff-Appellee
    Megan A. Ring, Colorado State Public Defender, Meredith E. O’Harris, Deputy
    State Public Defender, Denver, Colorado, for Defendant-Appellant
    ¶1    Defendant, Shawn Patrick Marston, appeals the judgment of
    conviction entered on a jury verdict finding him guilty of driving
    while ability impaired (DWAI). One of the issues he raises is
    whether the district court was required to hold a Shreck hearing,
    see People v. Shreck, 
    22 P.3d 68
     (Colo. 2001), before allowing a
    police officer to testify about the results of a horizontal gaze
    nystagmus (HGN) test the officer administered to him immediately
    before he was arrested. We hold that no such hearing was
    required; the results of such a test are generally admissible, if
    relevant, as evidence of impairment, so long as the person testifying
    about the administration and results of the test is competent to give
    such testimony. The officer in this case was, so the court didn’t err
    by allowing the officer’s testimony. We also reject Marston’s other
    challenges to the judgment and therefore affirm.
    I.    Background
    ¶2    Shortly before noon one day, J.P. was driving behind a red
    truck when he saw the truck straddling lanes and speeding up and
    slowing down erratically. He also saw the driver nodding off at the
    wheel. J.P. called 911 and followed the truck to a 7-Eleven.
    Marston got out of the truck and went into the 7-Eleven, at which
    1
    point J.P. approached a Jefferson County Sheriff’s deputy —
    Deputy Aaron Fosler — who had just pulled into the parking lot.
    J.P. told Deputy Fosler what he had seen. Deputy Fosler followed
    Marston into the 7-Eleven.
    ¶3    Deputy Fosler asked Marston to step outside the convenience
    store and answer some questions. Marston obliged. As Deputy
    Fosler held the door open and Marston walked out, he saw that
    Marston was “staggering, grabbing something to hold onto.”
    Outside, Deputy Fosler questioned Marston about his driving and
    whether he had been drinking. Marston told him that his driver’s
    license was suspended, told the officer he had driven to the
    7-Eleven but then said his girlfriend had driven him there, and told
    the officer he had downed several “mixed drinks” the night before at
    his girlfriend’s house. Unprompted, Marston asked Deputy Fosler if
    there was any way to keep his truck from being towed if he was
    taken to jail. Throughout this conversation, Deputy Fosler noticed
    2
    that Marston’s eyes were red and watery, he smelled of alcohol, and
    his speech was “thick tongued.”1
    ¶4    Based on Marston’s statements and Deputy Fosler’s
    observations, Deputy Fosler called for another officer, Deputy Kevin
    Kehl, to administer roadside field sobriety tests. Kehl did so. One
    such test was the HGN test. As discussed more fully below, that
    test requires the subject to follow an object (for example, a pen) with
    his eyes to the left and right. The person administering the test
    must watch the subject’s eyes to detect any involuntary “jerking” of
    his eyeballs.
    ¶5    At one point during the roadside tests, when Deputy Kehl was
    demonstrating a walk-and-turn maneuver, Marston said, “I couldn’t
    do that sober.” Deputy Kehl determined that Marston didn’t
    perform as a sober person would on the HGN test and the other
    roadside tests and arrested him. Marston refused to take a
    chemical test.
    1 Sometime during this conversation, a second deputy arrived and,
    for part of the time, stood nearby. That officer also noticed
    Marston’s signs of intoxication.
    3
    ¶6    After Marston’s girlfriend picked up the truck from the
    7-Eleven, she found bottles of vodka in the back of the truck. She
    testified at trial that, contrary to what Marston had told Deputy
    Fosler, she wasn’t with Marston the night before the arrest and in
    fact hadn’t seen him in several weeks.
    ¶7    The People charged Marston with driving under the influence
    (DUI) and driving under restraint. Marston went to trial on the DUI
    charge. The jury ultimately convicted him of the lesser included
    DWAI offense. The court then determined that Marston had at least
    three prior alcohol-related driving convictions and sentenced him
    for felony DWAI. See § 42-4-1301(1)(b), C.R.S. 2019.
    II.   Discussion
    ¶8    Marston contends that the district court erred by (1) denying
    his motion to suppress his statements to Deputy Fosler at the
    scene; (2) denying his request for a Shreck hearing on (a) the
    reliability of the HGN test and (b) Deputy Kehl’s expertise; and (3)
    determining that he had three prior alcohol-related driving
    convictions by a preponderance of the evidence rather than having
    the jury determine those convictions as elements that must be
    4
    proven beyond a reasonable doubt. We address and reject each
    contention in turn.
    A.    Marston’s Statements to Police
    ¶9     First, Marston contends that his statements to Deputy Fosler
    at the scene should have been suppressed because they were
    involuntary.2 We disagree.
    1.     Standard of Review
    ¶ 10   “A trial court’s suppression ruling presents a mixed question
    of fact and law.” People v. Ramadon, 
    2013 CO 68
    , ¶ 21. We won’t
    overturn the trial court’s factual findings if they are supported by
    competent evidence in the record; however, we review the legal
    effect of those facts de novo. Id.; Effland v. People, 
    240 P.3d 868
    ,
    878 (Colo. 2010) (“[T]he ultimate determination of whether a
    statement is voluntary is a legal question and is reviewed de novo.”).
    And we review any error under the constitutional harmless error
    standard; that is, we reverse unless the People show that the error
    2Marston’s motion didn’t specify what statements he wanted
    suppressed. At the suppression hearing, Marston’s attorney said
    she was challenging “everything at the scene.” But on appeal,
    Marston only challenges the voluntariness of his statements to
    Deputy Fosler.
    5
    was harmless beyond a reasonable doubt. Hagos v. People, 
    2012 CO 63
    , ¶ 11.
    2.    Applicable Law
    ¶ 11   “[A] defendant’s statements must be voluntary to be
    admissible as evidence.” Ramadon, ¶ 18. In determining whether a
    defendant’s statements were voluntary, we “must consider the
    totality of the circumstances ‘to determine whether the accused’s
    will was actually overborne by coercive police conduct.’” People v.
    Coke, 
    2020 CO 28
    , ¶ 18 (quoting Sanchez v. People, 
    2014 CO 56
    ,
    ¶ 11). To do so, we engage in a two-step inquiry: we first look to
    whether the police conduct was coercive; if so, we then look to
    whether that conduct “played a significant role in inducing the
    statements.” Ramadon, ¶ 20. The statements “must not be the
    product of any direct or implied promises, nor obtained by exerting
    an improper influence.” People v. Medina, 
    25 P.3d 1216
    , 1222
    (Colo. 2001).
    ¶ 12   To determine whether the police conduct was coercive, we may
    consider, among other things, the following factors:
    (1) whether the defendant was in custody;
    (2) whether the defendant was free to leave;
    6
    (3) whether the defendant was aware of the
    situation;
    (4) whether the police read Miranda rights to
    the defendant;
    (5) whether the defendant understood and
    waived Miranda rights;
    (6) whether the defendant had an opportunity
    to confer with counsel or anyone else prior
    to or during the interrogation;
    (7) whether the statement was made during
    the interrogation or volunteered later;
    (8) whether the police threatened [the]
    defendant or promised anything directly or
    impliedly;
    (9) the method or style of the interrogation;
    (10) the defendant’s mental and physical
    condition just prior to the interrogation;
    (11) the length of the interrogation;
    (12) the location of the interrogation; and
    (13) the physical conditions of the location
    where the interrogation occurred.
    Ramadon, ¶ 20 (quoting Medina, 25 P.3d at 1222-23).
    3.   Analysis
    ¶ 13   We agree with the district court’s determination that Marston’s
    will wasn’t overborne by coercive police conduct and that his
    statements were therefore voluntary. The following facts, almost all
    of which are undisputed, lead us to this conclusion:
    • Deputy Fosler asked Marston if he wouldn’t mind
    stepping outside and answering some questions; he
    didn’t order him to do so. Marston agreed.
    7
    • No officer made any threats or promises to Marston.
    • The encounter occurred outside, in a public place.
    • Marston seemed be aware of the situation. (He had been
    in this situation several times before.) For example,
    unprompted, he asked if there was any way he could
    prevent his truck from being towed if he was taken to jail.
    • Marston appeared to understand Deputy Fosler’s
    questions and gave responsive answers.
    • Marston wasn’t restrained in any way and hadn’t yet
    been taken into custody.
    • Deputy Fosler used a conversational tone.
    • The deputies didn’t use any subtle psychological
    pressure to get Marston to talk.
    ¶ 14   Marston asserts that his statements were coerced because
    more than one deputy was present, the two deputies stood close to
    him, the encounter lasted twenty to thirty minutes, he wasn’t given
    a Miranda advisement, and he wasn’t free to leave. But looking at
    the totality of the circumstances, as we must, see Coke, ¶ 18, we
    conclude that these facts don’t add up to coercion.
    8
    ¶ 15   People v. Zadran, 2013 CO 69M, presents an instructive
    comparison. In that case, the supreme court determined that the
    police officer’s statements to the defendant that “I think it would be
    in your best interest to talk to me[,]” “I think you are going to be
    interested in some of the things that I already know[,]” “It is what it
    is. You messed up. You know you messed up[,]” and “You want to
    get ahead of this. You want to make things right. You want a
    positive outcome from this. I’m trying to do the [least] invasive
    thing that I can do here[,]” didn’t show police coercion. And this
    even though the defendant was in custody and wasn’t free to leave.
    Id. at ¶¶ 15-19. The court contrasted the facts before it with those
    in cases in which the police exploited a defendant’s “particular set
    of vulnerabilities.” Id. at ¶¶ 17-18.
    ¶ 16   In terms of showing coercion, the facts of this case don’t even
    approach those in Zadran, in which the court found no coercion.
    Deputy Fosler simply asked Marston, in a conversational tone,
    questions about his driving and alcohol consumption. We see no
    indication that Marston’s will was overborne by coercive police
    conduct.
    9
    B.    Denial of a Shreck Hearing
    ¶ 17   Next, Marston contends that the district court erred by
    refusing to hold a Shreck hearing on the science, reliability, and
    margin of error of the HGN test, as well as Deputy Kehl’s expertise
    on those issues. We conclude that the district court didn’t err by
    denying Marston a hearing, but that even if it did, any error was
    harmless.
    1.    The District Court’s Ruling
    ¶ 18   After the prosecution endorsed Deputy Kehl as an expert in
    HGN testing, Marston filed a motion requesting a Shreck hearing to
    challenge the admissibility of the HGN test and Deputy Kehl’s
    qualifications as an expert. In response, the prosecution argued
    that a hearing wasn’t necessary, citing district court cases from
    Colorado and appellate court cases from other jurisdictions in
    which HGN testing had been found “reasonably reliable” and
    accepted by the scientific community. At a motions hearing, the
    district court heard argument from both sides as to why a Shreck
    hearing was or wasn’t necessary. It ultimately found that “the
    scientific community has accepted over many years the fact that the
    HGN is a reliable and relevant tool to help police officers determine
    10
    if someone is under the influence of alcohol[,]” and concluded that
    the science was reliable and that if the prosecution properly
    qualified Deputy Kehl as an expert, his testimony would be useful
    to the jury.
    2.    Standard of Review
    ¶ 19   We review a district court’s denial of a request for a Shreck
    hearing for an abuse of discretion. See People v. Rector, 
    248 P.3d 1196
    , 1201 (Colo. 2011) (“Once a party requests a Shreck analysis,
    a trial court is vested with the discretion to decide whether an
    evidentiary hearing would aid the court in its Shreck analysis.”). “A
    trial court abuses its discretion only if its decision is manifestly
    arbitrary, unreasonable, [or] unfair, or is based on a
    misunderstanding or misapplication of the law.” People v.
    Thompson, 
    2017 COA 5
    , ¶ 91. And “we review any error in denying
    a Shreck hearing under the nonconstitutional harmless error
    standard.” People v. Wilson, 
    2013 COA 75
    , ¶ 24; cf. Campbell v.
    People, 
    2019 CO 66
    , ¶ 34 (error in allowing officer to testify as a lay
    witness regarding HGN reviewed for nonconstitutional harmless
    error). We therefore reverse only if any error substantially
    11
    influenced the verdict or impaired the fairness of the trial. Wilson,
    ¶ 24.
    3.     Analysis
    ¶ 20      To decide whether the district court abused its discretion by
    allowing Deputy Kehl to testify about Marston’s performance on the
    HGN test without first holding a Shreck hearing, we proceed in the
    following steps. First, we discuss the nature of the test and its use
    in Colorado courts. Second, we discuss Shreck’s admissibility
    framework. Third, we assess whether there is sufficient indication
    that the HGN test satisfies Shreck’s admissibility test, or whether a
    Shreck hearing was required.
    a.        The HGN Test
    ¶ 21      The HGN test measures the subject’s ability to maintain visual
    fixation on an object as his eyes move from side to side. Nat’l
    Traffic Law Ctr., Am. Prosecutors Research Inst., Horizontal Gaze
    Nystagmus: The Science and the Law (n.d.),
    https://perma.cc/UW93-GHPD. (“Nystagmus” is a rapid,
    involuntary oscillation of the eyeballs.) An officer holds an object (a
    pen, small flashlight, or finger) about twelve to fifteen inches in
    front of a subject’s nose. The officer asks the subject to remove any
    12
    glasses, to stand still with his feet together and hands at his sides,
    and to focus on the object. The officer then moves the object slowly
    back and forth horizontally three times, observing whether each of
    the subject’s eyes smoothly tracks the object. Continuing Legal
    Education in Colorado, Inc., Colorado DUI Benchbook § 6.2.2
    (2019-2020 ed.); see also Am. Prosecutors Research Inst.,
    Admissibility of Horizontal Gaze Nystagmus Evidence 5 (2003),
    https://perma.cc/R36W-CCXR. The officer looks for three testing
    points for each eye (six total): lack of smooth pursuit, distinct
    jerking of the eyes at maximum deviation, and jerking that occurs
    before a forty-five-degree angle. Nat’l Highway Traffic Safety
    Admin., DWI Detection and Standardized Field Sobriety Test (SFST)
    Participant Manual Session 7, page 9 of 39 (rev. Feb. 2018),
    https://perma.cc/4R6E-ZB3A; see State v. Baue, 
    607 N.W.2d 191
    ,
    201-02 (Neb. 2000) (describing the test). If four or more of these
    clues are present, the subject’s blood alcohol content (BAC) is likely
    at or above 0.08%. DWI Detection at Session 8, page 37 of 95;
    Baue, 607 N.W.2d at 202.
    ¶ 22   The National Highway Traffic Safety Administration (NHTSA)
    standardized the HGN test along with the walk-and-turn and
    13
    one-leg-stand tests in 1981, finding that, combined, the tests can
    accurately determine whether a subject’s BAC is .10 or higher
    eighty-three percent of the time. Horizontal Gaze Nystagmus: The
    Science and the Law. Those tests are now the standard field
    sobriety tests in use across the country.
    ¶ 23   In Colorado, “virtually every judge now takes judicial notice of
    the scientific principles underlying HGN testing[,]” though
    Colorado’s appellate courts haven’t yet addressed the test’s
    admissibility. Colorado DUI Benchbook § 6.2.2.
    b.   Shreck
    ¶ 24   In Shreck, the Colorado Supreme Court adopted a “liberal,”
    “totality of the circumstances” test, grounded in relevant rules of
    evidence, for determining whether scientific evidence is admissible
    through expert testimony. To get there, the court first rejected the
    so-called Frye test (derived from Frye v. United States, 
    293 F. 1013
    (D.C. Cir. 1923)), which Colorado appellate courts had applied,
    albeit perhaps inconsistently, for several decades. The Frye test
    requires that a scientific conclusion gain “general acceptance in the
    particular field to which it belongs” as to both the underlying theory
    supporting the conclusion and the techniques and experiments
    14
    employing it, before evidence based on that conclusion can be
    introduced in court. Shreck, 22 P.3d at 73 (quoting Frye, 293 F. at
    1014). The court determined that the Frye test is too rigid and is
    inconsistent with the more flexible approach countenanced by the
    Colorado Rules of Evidence. Id. at 76-77.
    ¶ 25   The Shreck court also discussed the United States Supreme
    Court’s decision in Daubert v. Merrell Dow Pharmaceuticals, Inc.,
    
    509 U.S. 579
     (1993), which likewise rejected Frye, holding that its
    “rigid general acceptance requirement [is] at odds with the ‘liberal
    thrust’ of the Federal Rules [of Evidence] and their ‘general
    approach of relaxing the traditional barriers to opinion testimony.’”
    
    Id. at 588
     (quoting Beech Aircraft Corp. v. Rainey, 
    488 U.S. 153
    , 169
    (1988)). Rather than adopting the Daubert approach wholesale,
    however, the Colorado Supreme Court went its own way.
    ¶ 26   Ultimately, the court adopted a rubric supported by CRE 403
    and 702 “because their flexibility is consistent with a liberal
    approach that considers a wide range of issues.” Shreck, 22 P.3d at
    77. An admissibility analysis under Shreck requires the court to
    determine whether “(1) the scientific principles underlying the
    testimony are reasonably reliable; (2) the expert is qualified to opine
    15
    on such matters; (3) the expert testimony will be helpful to the jury;
    and (4) the evidence satisfies CRE 403.” Rector, 248 P.3d at 1200;
    see Shreck, 22 P.3d at 77-79. In making these determinations, the
    court can consider a broad range of indicia “that may be pertinent
    to the evidence at issue.” Shreck, 22 P.3d at 77. These may
    include, but certainly aren’t limited to, the factors identified in
    Daubert. Id. at 77-78.
    ¶ 27   Before applying the Shreck framework to the testimony at
    issue in this case, we pause to address Marston’s assertion that
    Shreck “is widely regarded as imposing a more rigorous ‘gatekeeper’
    function on trial courts than Frye did.” (The point matters because,
    as discussed below, some courts have applied the Frye test in
    determining HGN test admissibility, and so understanding the
    relative restrictiveness of the tests will prove informative.) To the
    extent Marston intends to suggest that the Shreck test is more
    limiting than the Frye test, he is wrong, for at least two reasons.
    ¶ 28   First, Marston’s assertion is based on a quote from an Alaska
    Supreme Court case, State v. Coon, 
    974 P.2d 386
    , 390 (Alaska
    1999), abrogated by State v. Sharpe, 
    435 P.3d 887
     (Alaska 2019),
    that is taken out of context. That case compared the Daubert test
    16
    (not the Shreck test, which the Colorado Supreme Court adopted
    two years later) to the Frye test. And in saying that the Daubert test
    imposes a more rigorous gatekeeper function, the Alaska court
    merely observed that, under Daubert, admissibility depends on
    consideration of several factors, while Frye gives dispositive weight
    to but one — general acceptance.
    ¶ 29   Second, Shreck itself repeatedly contrasts Frye’s “rigid”
    (indeed, too rigid) approach to the more “liberal” approach
    contemplated by the Colorado Rules of Evidence. See Shreck, 22
    P.3d at 76 (rejecting Frye because it “restricts the admissibility of
    reliable evidence that may not yet qualify as ‘generally accepted’”)
    (citation omitted).3 And the court emphasized that “[a]ny concerns
    that invalid scientific assertions will be admitted under this liberal
    standard are assuaged by Rule 702’s overarching mandate of
    reliability and relevance. . . . Such concerns are also mitigated by
    ‘[v]igorous cross-examination, presentation of contrary evidence,
    3Indeed, the court in Shreck concluded that certain scientific
    evidence that may not have been generally accepted was
    nonetheless admissible. People v. Shreck, 
    22 P.3d 68
    , 80-81 (Colo.
    2001).
    17
    and careful instruction on the burden of proof.’” 
    Id. at 78
     (quoting
    Daubert, 
    509 U.S. at 596
    ).
    c.    Application
    i.   HGN Test Evidence is Generally Admissible
    ¶ 30   A number of relevant considerations identified in Shreck
    support the admissibility of HGN test results as evidence of
    impairment:
    1. The technique has been tested and subjected to peer
    review and publication. See State v. Ruthardt, 
    680 A.2d 349
    , 357 (Del. Super. Ct. 1996) (citing some of the
    relevant literature); State v. Dahood, 
    814 A.2d 159
    , 166
    (N.H. 2002) (recognizing “extensive scientific literature
    dating back to the 1950s that thoroughly examines and
    critiques the HGN test and the theory underlying that
    test-that there is a strong correlation between the
    amount of alcohol a person consumes and the onset of
    nystagmus”); see, e.g., Marcelline Burns & Ellen W.
    Anderson, Nat’l Highway Traffic Safety Admin., A
    Colorado Validation Study of the Standardized Field
    Sobriety Test (SFST) Battery (Nov. 1995),
    18
    https://perma.cc/5MMA-NR8W; Gregory W. Good & Arol
    R. Augsburger, Use of Horizontal Gaze Nystagmus as a
    Part of Roadside Sobriety Testing, 63 Am. J. Optometry &
    Physiological Optics 467 (1986); V. Tharp, M. Burns, &
    H. Moskowitz, Nat’l Highway Traffic Safety Admin.,
    Development and Field Test of Psychophysical Tests for
    DWI Arrest (Mar. 1981), https://perma.cc/5HA3-S3KV.
    2. Studies have produced reliability rates indicating a
    significant correlation between test results and
    impairment. See, e.g., Horizontal Gaze Nystagmus: The
    Science and the Law (combined, the HGN test, the
    walk-and-turn test, and the one-leg-stand test accurately
    determine whether a subject’s BAC was .10 or higher
    eighty-three percent of the time); Jack Stuster &
    Marcelline Burns, Validation of the Standardized Field
    Sobriety Test Battery at BACs Below .10 Percent (Aug.
    1998), https://perma.cc/E5BL-PGFH (study showed that
    the HGN test could often accurately predict whether a
    subject’s BAC is at or above 0.08).
    19
    3. Standards have been developed to ensure consistency in
    the application of the test and the assessment of
    responses. See DWI Detection and Standardized Field
    Sobriety Test (SFST) Participant Manual at Session 4, page
    35 of 36, Session 7, pages 8-11 of 39 (providing
    instructions for application and evaluation of the HGN
    test nationwide).
    4. There is substantial specialized literature dealing with
    the technique. See Dahood, 814 A.2d at 166 (reviewing
    some of the literature); see, e.g., Stephanie E. Busloff,
    Comment, Can Your Eyes Be Used Against You — The
    Use of the Horizontal Gaze Nystagmus Test in the
    Courtroom, 
    84 J. Crim. L. & Criminology 203
     (Spring
    1993).
    5. The evidence has been offered in many other cases in
    Colorado as evidence of alcohol impairment. See, e.g.,
    Campbell, ¶¶ 7, 13-15 (HGN test results admitted at
    trial); People v. Haack, 
    2019 CO 52
    , ¶¶ 1, 8 (trial court
    20
    found that HGN test results would have been admissible
    but for an unrelated constitutional violation).4
    See Shreck, 22 P.3d at 77-78 (identifying these considerations as
    relevant).
    ¶ 31   As well, a survey of case law from other jurisdictions shows
    that most allow evidence of HGN test results as evidence of
    impairment. Some of these decisions employ a Daubert or
    Shreck-like analysis, but some employ the even more restrictive
    Frye test. See, e.g., Ballard v. State, 
    955 P.2d 931
    , 940 (Alaska Ct.
    App. 1998) (HGN evidence meets Frye test if results are offered to
    show a person has consumed alcohol and is potentially impaired),
    overruled on other grounds as recognized by Alvarez v. State, 
    249 P.3d 286
     (Alaska 2011); State v. City Court, 
    799 P.2d 855
    , 859 (Ariz.
    1990) (HGN test satisfies the Frye standard if offered only as
    evidence of impairment); State v. Commins, 
    850 A.2d 1074
    , 1080-81
    (Conn. App. Ct. 2004) (HGN test evidence satisfied Daubert test),
    4 As noted above, the prosecution cited several trial court decisions
    admitting evidence of HGN test results in responding to Marston’s
    motion for a Shreck hearing. Marston has never disputed the point
    that Colorado trial courts regularly admit such evidence.
    21
    aff’d on other grounds, 
    886 A.2d 824
     (Conn. 2005); Ruthardt, 
    680 A.2d at 356-60
     (applying Shreck-like test; HGN test results
    admissible as evidence of impairment); Williams v. State, 
    710 So. 2d 24
    , 30-32 (Fla. Dist. Ct. App. 1998) (the HGN test is a reliable
    indicator of the presence of alcohol in blood, and there is no need
    for trial courts to reapply a Frye analysis to HGN); Hawkins v. State,
    
    476 S.E.2d 803
    , 806-08 (Ga. Ct. App. 1996) (HGN test results
    admissible without expert testimony regarding the scientific validity
    of the test; applying a Shreck-like totality of the circumstances test);
    State v. Gleason, 
    844 P.2d 691
    , 694-95 (Idaho 1992) (HGN
    testimony admissible under Frye test as evidence of impairment);
    State v. Taylor, 
    694 A.2d 907
    , 911-12 (Me. 1997) (applying Frye
    test; HGN test results admissible as evidence of impairment);
    Schultz v. State, 
    664 A.2d 60
    , 69-70 (Md. Ct. Spec. App. 1995)
    (courts may take judicial notice of the results of an HGN test); State
    v. Klawitter, 
    518 N.W.2d 577
    , 584-86 (Minn. 1994) (HGN test
    results satisfied Frye test); State v. Hill, 
    865 S.W.2d 702
    , 703-04
    (Mo. Ct. App. 1993) (HGN test satisfies Frye test if offered as
    evidence of intoxication), overruled on other grounds by State v.
    Carson, 
    941 S.W.2d 518
     (Mo. 1997); Baue, 607 N.W.2d at 201-04
    22
    (HGN test results admissible as evidence of impairment under Frye
    test); Dahood, 814 A.2d at 166-67 (HGN test results admissible
    under Daubert test); State v. Aleman, 
    194 P.3d 110
    , 115-16 (N.M.
    Ct. App. 2008) (HGN test results admissible under Daubert test);
    City of Fargo v. McLaughlin, 
    512 N.W.2d 700
    , 703-08 (N.D. 1994)
    (HGN test results admissible under Frye test if offered in
    conjunction with other field sobriety tests); State v. O’Key, 
    899 P.2d 663
    , 689 (Or. 1995) (HGN test results admissible under Daubert
    test); Emerson v. State, 
    880 S.W.2d 759
    , 763-69 (Tex. Crim. App.
    1994) (HGN test results admissible under Texas Rule of Criminal
    Evidence 702; applying Daubert-like test); see also United States v.
    Horn, 
    185 F. Supp. 2d 530
    , 561 (D. Md. 2002) (collecting cases).
    ¶ 32   Marston cites a few cases rejecting the admissibility of HGN
    test results under the facts before them. Ex Parte Malone, 
    575 So. 2d 106
     (Ala. 1990); State v. Meador, 
    674 So. 2d 826
     (Fla. Dist. Ct.
    App. 1996); People v. McKown, 
    875 N.E.2d 1029
     (Ill. 2007); State v.
    Witte, 
    836 P.2d 1110
     (Kan. 1992); State v. Lasworth, 
    42 P.3d 844
    (N.M. Ct. App. 2001); Commonwealth v. Apollo, 
    603 A.2d 1023
     (Pa.
    23
    Super. Ct. 1992).5 But those cases usually apply the Frye test,
    which, as discussed above, is more restrictive than the “liberal”
    Shreck test. And even then, they don’t reject such evidence
    outright, but hold that the evidence before them wasn’t sufficient to
    establish reliability and leave open the possibility that such
    evidence could be presented. See also Commonwealth v. Sands,
    
    675 N.E.2d 370
    , 371-73 (Mass. 1997) (trial court erred by allowing
    officer to testify about HGN test results without being qualified as
    an expert, but indicating that HGN test results would be admissible
    if supported by expert testimony from the person administering the
    test); State v. Helms, 
    504 S.E.2d 293
    , 294-96 (N.C. 1998) (same);
    State v. Murphy, 
    953 S.W.2d 200
    , 202-03 (Tenn. 1997) (same); State
    v. Cissne, 
    865 P.2d 564
    , 566-69 (Wash. Ct. App. 1994) (same).6
    5 Marston also cites State v. Superior Court, 
    718 P.2d 171
     (Ariz.
    1986), in support of his position. But the court in that case
    actually held that HGN test results are admissible as evidence of
    impairment (but not as evidence of a specific BAC level). 
    Id. at 182
    .
    6 In at least one instance, the court reversed course after additional
    evidence of reliability was presented. State v. Aleman, 
    194 P.3d 110
    , 115-16 (N.M. Ct. App. 2008) (backtracking on its earlier
    holding in State v. Lasworth, 
    42 P.3d 844
     (N.M. Ct. App. 2001)).
    24
    ¶ 33   The weight of judicial authority therefore favors admissibility
    of HGN test results without the need for additional evidence of
    scientific reliability — at least if the evidence is offered only as
    evidence of impairment and not a specific BAC level.7
    ¶ 34   We recognize that there isn’t unanimous agreement among
    academics and other commentators concerning the reliability of the
    HGN test. But much of the disagreement doesn’t relate to whether
    alcohol can cause nystagmus — that point is widely accepted.
    Rather, some have noted that there can be reasons other than
    alcohol impairment that may explain test results in a particular
    case, see, e.g., William A. Pangman, Horizontal Gaze Nystagmus:
    Voodoo Science, 2 DWI J. 1, 2 (1987), or that police officers may not
    be sufficiently trained in administering the test. And some claim a
    higher incidence of false positives than reported by NHTSA and
    7 A few courts have held that this type of evidence isn’t scientific
    evidence at all, and therefore isn’t subject to restrictions on
    scientific evidence. State v. Murphy, 
    451 N.W.2d 154
    , 156-58 (Iowa
    1990); State v. Nagel, 
    506 N.E.2d 285
    , 286 (Ohio Ct. App. 1986);
    Salt Lake City v. Garcia, 
    912 P.2d 997
    , 1000-01 (Utah Ct. App.
    1996). We align ourselves, however, with the vast majority of courts
    that have held that such evidence is based, at least in part, on
    scientific principles.
    25
    other studies. Busloff, 84 J. Crim. L. & Criminology at 211 (noting
    that NHTSA’s “experimental procedure has been further challenged
    for its intentional screening out of those individuals highly likely to
    be misclassified as false positives”). We believe such concerns go to
    the weight of the evidence, not its admissibility. See Ruthardt, 
    680 A.2d at 359-60
     (so holding); Dahood, 814 A.2d at 166-67 (same).
    They can be addressed through the presentation of evidence by the
    defense, cross-examination, and rigorous application of the rules
    governing an expert’s qualifications. See Daubert, 
    509 U.S. at 596
    (“Vigorous cross-examination, presentation of contrary evidence,
    and careful instruction on the burden of proof are the traditional
    and appropriate means of attacking shaky but admissible
    evidence.”); Shreck, 22 P.3d at 78 (same).
    ¶ 35   We therefore conclude that evidence of HGN test results is
    admissible as evidence of impairment if offered through a qualified
    expert witness. Contrary to Marston’s assertion, such an expert
    doesn’t have to be an expert in the science underlying the test. It is
    enough that the witness is an expert in administering the test and
    interpreting the subject’s responses. See, e.g., Ballard, 
    955 P.2d at 942
     (trooper could testify about the results of the HGN test because
    26
    the court could find he was qualified to administer the test and
    assess the results); People v. Leahy, 
    882 P.2d 321
    , 336 (Cal. 1994)
    (once HGN testing is shown to be generally accepted, officers may
    be deemed qualified to testify as to test results and the prosecution
    won’t be required to submit expert testimony confirming a police
    officer’s evaluation of an HGN test); Taylor, 
    694 A.2d at 912
     (“A
    proper foundation shall consist of evidence that the officer or
    administrator of the HGN test is trained in the procedure and the
    test was properly administered.”); State v. Torres, 
    976 P.2d 20
    ,
    34-35 (N.M. 1999) (the expert is qualified to testify if it is shown
    that he had ability and training to administer the HGN test
    properly, and that he did in fact administer the test properly); see
    also Campbell, ¶¶ 26-31 (officer testifying as to HGN test results
    must be qualified as an expert in administration and interpretation
    of the test).
    ¶ 36    Though a party may request a Shreck hearing on the
    admissibility of the proposed testimony, a trial court isn’t required
    to grant that request if it has “sufficient information to make
    specific findings under CRE 403 and CRE 702 about the reliability
    of the scientific principles involved, the expert’s qualification to
    27
    testify to such matters, the helpfulness to the jury, and potential
    prejudice.” Rector, 248 P.3d at 1201. The district court in this case
    had ample information before it from which it could determine the
    admissibility of the HGN test results without granting Marston’s
    request for a Shreck hearing. And Deputy Kehl was sufficiently
    qualified to testify about the administration and interpretation of
    the test. (Marston doesn’t contest this point.) Though the court
    didn’t make extensive findings, it didn’t abuse its discretion.
    ii.   Alternatively, Any Error Was Harmless
    ¶ 37   Even if the district court did err, we agree with the People that
    any error was harmless.
    ¶ 38   In Campbell, the supreme court determined that while the
    district court erred by allowing a police officer to testify about the
    results of an HGN test without being qualified as an expert, the
    error was harmless. Campbell, ¶¶ 1-2, 35. The court discussed the
    “overwhelming” evidence against Campbell aside from the HGN test,
    including the following:
    • “Campbell’s breath had an odor of alcohol.”
    • “[H]is eyes were bloodshot.”
    • “[H]is speech was slurred.”
    28
    • He was uncoordinated: “he dropped his wallet while
    trying to retrieve his identification[,]” and, “when
    Campbell tried to get out of his truck, the officer saw him
    reach for the door handle twice without success before
    grabbing it and opening the door.”
    • Bottles of alcohol were found in his car.
    • He failed two of the other field sobriety tests.
    • He had admitted to consuming alcohol.
    • He took two breath tests, which showed BAC levels of
    0.07 and 0.086, respectively.
    Id. at ¶¶ 36-40.
    ¶ 39   There is similar overwhelming evidence against Marston:
    • Two of the three officers reported that Marston’s breath
    smelled like alcohol.
    • All three observed that he had bloodshot eyes.
    • Two of the three noticed that his speech was slurred.
    • Marston had trouble keeping his balance as he walked
    out of the 7-Eleven into the parking lot, and two of the
    29
    three officers reported that he had to reach to keep his
    balance.
    • Bottles of alcohol were found in the truck.
    • Marston didn’t complete the other two field sobriety tests
    as a sober person would. Deputy Kehl observed three of
    eight clues on the walk-and-turn test. On the
    one-leg-stand test, Marston could only lift his leg for
    approximately four seconds.
    • Marston admitted to drinking alcohol the night before.
    ¶ 40      Unlike Campbell, Marston didn’t submit to a breath test. (Nor
    did he submit to a blood test.) But a witness saw him driving
    erratically and nodding off at the wheel. And Marston said, “I
    couldn’t do that sober,” when Deputy Kehl demonstrated the
    walk-and-turn maneuver.
    ¶ 41      Because of the overwhelming amount of evidence against
    Marston independent of the HGN test results, we conclude that any
    error in allowing Deputy Kehl to testify about those results without
    first holding a Shreck hearing didn’t substantially influence the
    verdict or impair the fairness of the trial. See Hagos, ¶ 12; Wilson,
    ¶ 24.
    30
    C.      Prior Convictions
    ¶ 42   Lastly, Marston contends that the district court erred by
    finding that he had at least three prior alcohol-related driving
    convictions by a preponderance of the evidence rather than
    submitting the issue to the jury for it to decide beyond a reasonable
    doubt. He argues that the prior convictions are elements of the
    crime. We disagree.
    ¶ 43   Several divisions of this court have determined that such prior
    convictions operate as sentence enhancers, not as elements, and
    therefore don’t have to be decided by a jury. See People v. Ambrose,
    
    2020 COA 112
    , ¶ 40; People v. Jiron, 
    2020 COA 36
    , ¶ 14; People v.
    Quezada-Caro, 
    2019 COA 155
    , ¶ 24; People v. Gwinn, 
    2018 COA 130
    , ¶ 49. We agree with those divisions and disagree with another
    division’s holding to the contrary. See People v. Viburg, 2020 COA
    8M, ¶ 28.
    III.   Conclusion
    ¶ 44   The judgment is affirmed.
    JUDGE GOMEZ concurs.
    JUDGE WELLING concurs in part and dissents in part.
    31
    JUDGE WELLING, concurring in part and dissenting in part.
    ¶ 45   I concur fully in Parts II.A and II.B of the majority opinion but
    dissent as to Part II.C. I do so for the reasons set forth by Judge
    Berger in People v. Viburg, 2020 COA 8M (petition for cert. filed Mar.
    12, 2020), which I joined. See also People v. Schreiber, 
    226 P.3d 1221
    , 1225-27 (Colo. App. 2009) (Bernard, J., concurring in part
    and dissenting in part). Accordingly, I would reverse Marston’s
    felony DUI conviction and remand the case for further proceedings.
    I wouldn’t reach Marston’s contention on appeal that double
    jeopardy bars retrial on the felony DUI. Instead, as in Viburg, I
    would order that “[i]f there is a retrial of the felony DUI charge and
    [Marston] interposes a double jeopardy defense, the trial court must
    rule on that defense.” Viburg, ¶ 32 (“express[ing] no opinion
    regarding the merits of any such defense”).
    32