                                                                    FILED BY CLERK
                        IN THE COURT OF APPEALS                        AUG 14 2012
                            STATE OF ARIZONA
                                                                         COURT OF APPEALS
                              DIVISION TWO                                 DIVISION TWO


THE STATE OF ARIZONA,               )
                                    )
              Petitioner/Appellant, )               2 CA-CV 2011-0197
                                    )               DEPARTMENT B
         v.                         )
                                    )               OPINION
JOSEPH COOPERMAN,                   )
                                    )
             Respondent/Appellee. )
                                    )


           APPEAL FROM THE SUPERIOR COURT OF PIMA COUNTY

                                 Cause No. C20117903

                          Honorable John S. Leonardo, Judge

                                     AFFIRMED


Michael G. Rankin, Tucson City Attorney
 By Baird S. Greene and William F. Mills                                       Tucson
                                                    Attorneys for Petitioner/Appellant

City of Tucson Public Defender
 By Stefan F. Niemiec                                                          Tucson

  and

Law Office of Nesci and St. Louis
 By James Nesci                                                              Tucson
                                                   Attorneys for Respondent/Appellee

Stephen Paul Barnard                                                          Tucson
                                                           Attorney for Amici Curiae
                                                Arizona Attorneys for Criminal Justice
V Á S Q U E Z, Presiding Judge.


¶1            In Guthrie v. Jones, 202 Ariz. 273, ¶ 2, 43 P.3d 601, 602 (App. 2002), this

court held that evidence regarding breath-to-blood partition ratios1 is inadmissible in a

prosecution for driving or being in actual physical control of a vehicle with an alcohol

concentration of .08 or more within two hours of driving, in violation of A.R.S. § 28-

1381(A)(2).   However, we also held that when the state uses breath-test results to

establish a presumption of intoxication in a prosecution for driving under the influence of

an intoxicant (DUI) while impaired to the slightest degree, see § 28-1381(A)(1) and (G),

the defendant may introduce partition-ratio evidence to rebut the presumption. Id. ¶ 14.

¶2            In this case involving a prosecution under both § 28-1381(A)(1) and (A)(2),

the state filed a motion in limine to preclude Joseph Cooperman from introducing at his

trial in the Tucson City Court partition-ratio evidence contesting the accuracy of the

Intoxilyzer 8000 breath tests. The city court denied the state’s motion, and the state filed

a special action challenging that ruling in the superior court. The state now appeals from

the superior court’s denial of relief. Relying on Guthrie, the state contends the superior

court abused its discretion by affirming the city court’s ruling. For the reasons stated

below, we affirm.




       1
        Partition ratios are used to correlate the amount of alcohol in a person’s breath
into the amount of alcohol in the person’s blood. Guthrie v. Jones, 202 Ariz. 273, ¶ 5, 43
P.3d 601, 602 (App. 2002).
                                             2
                          Factual and Procedural Background

¶3            On June 20, 2010, a Tucson police officer cited and arrested Cooperman for

DUI while impaired to the slightest degree, in violation of § 28-1381(A)(1), and, based

on the results of duplicate Intoxilyzer breath tests, for driving or being in actual physical

control of a vehicle with an alcohol concentration of .08 or more within two hours of

driving, in violation of § 28-1381(A)(2).

¶4            Before trial, the state moved to preclude Cooperman from presenting

evidence of partition ratios, breath and body temperatures, breathing patterns, and radio

frequency interference (RFI)2 to contest the accuracy of his breath-test results. At an

evidentiary hearing on the motion, the city court heard conflicting testimony from the

state’s expert, Michael Sloneker, and the defendant’s expert, Chester Flaxmayer,

concerning the effect of using partition ratios and other physiological variables on the

accuracy of breath tests. The court issued a thorough, five-page ruling denying the state’s

motion, but granting an instruction limiting the relevancy of the partition-ratio evidence

to the (A)(1) charge.

¶5            The state then filed a petition for special action with the superior court.

The respondent judge accepted jurisdiction but denied relief, affirming the city court’s


       2
         At the evidentiary hearing, the state conceded that RFI should not have been
included in its motion in limine because RFI is a proper “subject for attack anytime
you’re using an Intoxilyzer.” However, the state requested permission to modify its
motion to replace RFI with hematocrit as a factor it sought to preclude, and the city court
granted that request. Hematocrit is “a device for separating the cells and other particulate
elements of the blood from the plasma,” Stedman’s Medical Dictionary 558 (3d
unabridged lawyers’ ed. 1972), and Cooperman maintains that it can affect breath-test
results.
                                             3
ruling. The state filed this appeal. We have jurisdiction pursuant to A.R.S. §§ 12-

120.21(A)(1), 12-2101(A)(1), and Rule 8(a), Ariz. R. P. Spec. Actions.

                                         Discussion

¶6            Under Arizona’s statutory scheme, a defendant accused of drinking and

driving or being in actual control of a vehicle can be charged with multiple DUI-related

offenses. See A.R.S. §§ 28-1381 through 28-1383. Under § 28-1381(A)(1), the state

must prove the defendant was driving or in actual physical control of a vehicle “[w]hile

under the influence of intoxicating liquor . . . if the person is impaired to the slightest

degree.” And, for a violation of § 28-1381(A)(2), the state must prove the defendant had

“an alcohol concentration of .08 or more within two hours of driving or being in actual

physical control of the vehicle.” Cooperman was charged under both subsections.

¶7            Arizona’s implied consent law, A.R.S. § 28-1321(A), provides that any

person operating a motor vehicle in this state and arrested for DUI “gives consent . . . to a

test or tests of [his] blood, breath, urine or other bodily substance for the purpose of

determining alcohol concentration.”          If the test shows the defendant’s alcohol

concentration within two hours of the time of driving or being in actual physical control

was .08 or more, “it may be presumed that the defendant was under the influence of

intoxicating liquor” for purposes of the (A)(1) offense.3             § 28-1381(G)(3).     The

presumption, however, does not preclude the introduction of “any other competent



       3
       If the defendant has an alcohol concentration of .05 or less, it may be presumed
he was not under the influence; if it is in excess of .05 but less than .08, that fact raises no
presumption. § 28-1381(G)(1)-(2).
                                               4
evidence bearing on the question of whether or not the defendant was under the influence

of intoxicating liquor.” § 28-1381(H).

¶8            “Alcohol in the breath does not cause impairment; impairment results when

alcohol enters the body, is absorbed into the bloodstream, and is transported to the central

nervous system and the brain.” Guthrie, 202 Ariz. 273, ¶ 5, 43 P.3d at 602. “[B]reath

alcohol readings nonetheless indicate blood alcohol levels, and . . . the percentage of

alcohol in 100 milliliters of blood could be equated to the percentage of alcohol in 210

liters of breath.” Id. ¶¶ 5-6. Accordingly, our legislature adopted a 2,100:1 ratio of

breath-to-blood alcohol. Id. ¶ 6. The 2,100:1 partition ratio is “an estimation” and varies

among individuals based on several factors, including: body temperature, breathing

patterns, blood consistency, and environmental factors. Id. ¶¶ 7-8. Evidence of such

variability, nevertheless, is admissible only in certain circumstances.

¶9            For example, in Guthrie, this court held partition-ratio evidence is

inadmissible in a prosecution under § 28-1381(A)(2). 202 Ariz. 273, ¶ 10, 43 P.3d at

603. Section 28-1381(A)(2) prohibits a person from driving or physically controlling a

vehicle if the person has an “alcohol concentration” of .08 or more. And A.R.S. § 28-

101(2) defines alcohol concentration, when expressed as a percentage, as either “[t]he

number of grams of alcohol per one hundred milliliters of blood,” or “[t]he number of

grams of alcohol per two hundred ten liters of breath.” “The statutes thus permit[] either

a breath alcohol reading or a blood alcohol reading to establish the element of alcohol

concentration without regard to the question how the former might be converted to the

latter.” Guthrie, 202 Ariz. 273, ¶ 10, 43 P.3d at 603. Accordingly, in Guthrie, we

                                             5
reasoned that the accuracy of the 2,100:1 partition ratio was irrelevant in a prosecution

under (A)(2) because “it [i]s illegal to drive or physically control a vehicle if, according

to a test within two hours, the number of grams of alcohol per 210 liters of breath

exceeded [.08].” Id. However, we also held that, in a prosecution under (A)(1), where

the state uses the defendant’s breath-test results to establish a presumption of intoxication

pursuant to § 28-1381(G), the defendant may introduce evidence challenging the

accuracy of the partition-ratio calculation to rebut that presumption. Id. ¶ 14.

¶10           In its petition for special action to the superior court, the state contended the

city court had abused its discretion by ruling that (1) the § 28-1381(G) presumption arises

by operation of law when test results are admitted in evidence, even when the state

“never sought to take advantage of the . . . statutory presumption”; (2) once the

presumption arises, evidence of the variability of the partition ratio in the general

population is relevant and admissible in an (A)(1) case; and (3) evidence of hematocrit,

breathing patterns, and breath and body temperature—and their effect on breath tests—

are relevant and admissible in both types of DUI cases. On appeal, the state essentially

reurges these arguments, asserting the superior court abused its discretion by affirming

the city court’s ruling, which it contends is “contrary to [the] caselaw.” We address each

argument in turn.

Appellate Review

¶11           When a special action initiated in the superior court is appealed to this

court, we must conduct a bifurcated review. Bazzanella v. Tucson City Court, 195 Ariz.

372, ¶ 3, 988 P.2d 157, 159 (App. 1999). First, we consider the superior court’s decision

                                              6
to accept or refuse jurisdiction; second, we consider the merits of the superior court’s

decision. Id. Here, the court accepted jurisdiction, finding there was “no equally plain,

speedy, and adequate remedy available by appeal.” Neither party argues the court erred

in so finding, and we agree the state had no avenue to appeal the city court’s order and

special-action jurisdiction therefore was appropriate. See State ex rel. Thomas v. Duncan,

216 Ariz. 260, ¶ 4, 165 P.3d 238, 240 (App. 2007) (state can appeal order granting

motion to preclude evidence, but not order denying preclusion).

¶12           Accordingly, we turn to the merits of the superior court’s decision. “The

denial of special action relief is a discretionary decision for the superior court,” State ex

rel. Dean v. City Court of City of Tucson, 123 Ariz. 189, 192, 598 P.2d 1088, 1011 (App.

1979), but we review questions of law, such as the interpretation of a statute, de novo,

Files v. Bernal, 200 Ariz. 64, 66, 22 P.3d 57, 59 (App. 2001). “Generally, a court abuses

its discretion where the record fails to provide substantial support for its decision or the

court commits an error of law in reaching the decision.” Id. at 65, 22 P.3d at 58. Here,

the court denied relief and confirmed the city court’s order, finding it “thorough, well

considered and consistent with the evidentiary record and cited case law.” 4 We conclude

the record and the case law provide ample support for the superior court’s decision.

Statutory Presumption

¶13           First, we address the state’s argument that evidence regarding the partition-

ratio calculation is inadmissible where “the [s]tate does not [rely on] the statutory

       4
        Because the superior court essentially adopted the city court’s reasoning, we
likewise consider it in deciding the issues on appeal.

                                             7
presumption of impairment.”      Guthrie permits partition-ratio rebuttal evidence in a

prosecution under (A)(1) when the state introduces breath-test results and thereby raises

the § 28-1381(G) presumption. But the state apparently suggests that if it does not raise

the presumption expressly, then partition-ratio evidence is neither relevant nor

admissible. And, it asserts it does not intend to use Cooperman’s breath-test results in

order to take advantage here of the statutory presumption on the (A)(1) charge.5

¶14           Cooperman counters that the state has misinterpreted Guthrie. He contends

Guthrie stands for the proposition that in an (A)(1) prosecution, the statutory presumption

effectively is raised whenever the state introduces evidence of alcohol concentration, and

a defendant is entitled to rebut that presumption by challenging the breath-to-blood

partition ratio. Cooperman points to § 28-1381(H) as evidence of the legislature’s intent

to ensure that defendants prosecuted for DUI are afforded their due process right to

present a complete defense, which includes introducing evidence to rebut the § 28-

1381(G) presumption.

¶15           The city court found there is no language in Guthrie, or § 28-1381(G),

limiting use of the presumption in the manner suggested by the state. Rather, the court

concluded the presumption “will always apply” in an (A)(1) prosecution once the state

introduces evidence of the Intoxilyzer results to prove the defendant was driving under


       5
        Even if the state did not intend to request that the jury be informed of the
statutory presumption of intoxication, it nonetheless must introduce the breath-test results
into evidence in order to prove the (A)(2) charge; otherwise, it would have no other
evidence of Cooperman’s alcohol concentration. See State v. Superior Court, 149 Ariz.
269, 279-80, 718 P.2d 171, 181-82 (1986) (cannot convict defendant under (A)(2)
without analysis of blood, breath, or urine showing alcohol concentration).
                                             8
the influence of intoxicating liquor. In other words, the presumption “does not offer an

opt out clause” for the state.

¶16           The interpretation of a statute is a question of law we review de novo. State

v. Bolding, 227 Ariz. 82, ¶ 5, 253 P.3d 279, 282 (App. 2011). Our primary goal in

interpreting a statute is to effectuate the intent of the legislature. State v. Ross, 214 Ariz.

280, ¶ 22, 151 P.3d 1261, 1264 (App. 2007). We look first to the plain language of the

statute as the best indicator of that intent and give that language effect when it is clear

and unambiguous. Fragoso v. Fell, 210 Ariz. 427, ¶ 7, 111 P.3d 1027, 1030 (App. 2005).

We “will not read into a statute something which is not within the manifest intent of the

legislature as reflected by the statute itself.” State v. Ritch, 160 Ariz. 495, 497, 774 P.2d

234, 236 (App. 1989).

¶17           We find the language of § 28-1381(G) clear and unambiguous. According

to that statute, the defendant’s alcohol concentration—as determined by an analysis of his

blood, breath, or other bodily substance taken within two hours of driving or being in

actual physical control of a vehicle—“gives rise” to certain presumptions. And, contrary

to the state’s position, the statutory presumption of intoxication is raised in a prosecution

for an (A)(1) offense whenever the state introduces evidence that a defendant had an

alcohol concentration of .08 or more. We find nothing in the statute’s language to

support the state’s argument that the presumption applies only when expressly invoked

by the state.6 Our interpretation of the statute is consistent with Guthrie which, as the


       6
       Either party can introduce evidence of the defendant’s alcohol concentration,
thereby triggering the statutory presumption. See State v. Klausner, 194 Ariz. 169, ¶ 18,
                                              9
city court points out, “carefully never implies that the [s]tate could choose not to use the

presumption” despite introducing alcohol-concentration evidence in an (A)(1)

prosecution.

¶18            Trial courts have a duty to instruct the jury on the general principles of law

that pertain to a criminal offense. State v. McAlvain, 104 Ariz. 445, 448, 454 P.2d 987,

990 (1969); see also State v. Clark, 112 Ariz. 493, 495, 543 P.2d 1122, 1124 (1975)

(failure to instruct on matter vital to rights of defendant constitutes fundamental error).

This duty exists regardless of who requests a particular instruction. McAlvain, 104 Ariz.

at 448, 454 P.2d at 990.       Although the presumption contained in § 28-1381(G) is

permissive and “nothing more than an inference,” State v. Seyrafi, 201 Ariz. 147, ¶ 9, 32

P.3d 430, 433 (App. 2001), the trial judge still has a duty to instruct the jury on this

general principle of law pertaining to a prosecution under (A)(1) once evidence is

introduced of the defendant’s alcohol concentration.

General Partition-Ratio Evidence

¶19            Next, we consider the state’s argument that “any defendant who wishes to

challenge the ‘standard’ or ‘generally accepted’ [partition] ratio on which the Intoxilyzer

(5000 or 8000) is based, must present evidence of his own ratio at the time of the test.”

The state maintains that “the logic [and language] of Guthrie” compel that result and

“[t]he probative value of any other evidence (such as a ‘hypothetical’ person) is

substantially outweighed by the danger of unfair prejudice.” In response, Cooperman


978 P.2d 654, 658 (App. 1998) (“Defendant is always free to prove . . . his [alcohol
concentration] . . . and will be entitled to the benefit of the presumptions as they apply.”).
                                             10
argues that Guthrie “d[oes] not preclude a defendant from introducing studies or other

evidence about variations in the population.”

¶20           For purposes of our review, we treat the state’s motion in limine as a

motion to suppress, State v. Rodriguez, 126 Ariz. 28, 30, 612 P.2d 484, 486 (1980), and

consider only the evidence presented at the suppression hearing, viewing that evidence in

the light most favorable to the city court’s ruling, State v. Gay, 214 Ariz. 214, ¶ 4, 150

P.3d 787, 790 (App. 2007). We are mindful that a trial court has broad discretion to

determine the admissibility of evidence and is best suited to conduct any balancing of

probative value and prejudicial effect pursuant to Rule 403, Ariz. R. Evid. State v.

Harrison, 195 Ariz. 28, ¶ 21, 985 P.2d 513, 518 (App. 1998). On review, we also

consider “the evidence in the ‘light most favorable to its proponent, maximizing its

probative value and minimizing its prejudicial effect.’” Id., quoting State v. Castro, 163

Ariz. 465, 473, 788 P.2d 1216, 1224 (App. 1989).

¶21           We believe the state interprets Guthrie too broadly. In that case, we said

partition-ratio evidence is relevant and admissible in an (A)(1) but not an (A)(2)

prosecution. Although dictum in Guthrie may suggest otherwise, we did not address

specifically whether a defendant is limited to evidence of his own partition ratio, or

whether he may show generally that partition ratios vary from person to person, and even

from moment to moment for the same person.7 Noting that Guthrie does not provide


       7
        Language in Guthrie arguably supports both parties’ positions. For example, in
Guthrie, we said, “the municipal court erred by precluding Guthrie’s effort to establish
that his particular partition ratio on the date in question differed significantly from the
norm,” which tends to support the state’s argument that only defendant-specific,
                                            11
definitive guidance on this issue, the city court relied on cases from other jurisdictions,

namely, State v. Hanks, 772 A.2d 1087 (Vt. 2001), and People v. McNeal, 46 Cal. 4th

1183 (2009). And, based on those cases, the court concluded that if “the [s]tate has relied

upon or will rely upon an [I]ntoxilyzer result in any way to argue impairment, evidence

of the variability of the partition ratio in the general population is relevant and

admissible” to challenge the presumption of intoxication in an (A)(1) case. It noted that,

because an individual’s partition ratio constantly varies, a calculation of his ratio at some

later time would not be relevant to discredit the earlier Intoxilyzer test or the partition

ratio it employed.8 The court concluded that the general variability of partition ratios

makes the evidence relevant and that, although “questions can be raised in individual

cases about whether th[e] assum[ed ratio] tends to underestimate most people’s result, the

defense has a right to raise the issue, and cast doubt upon the theory” that the Intoxilyzer

results accurately demonstrate the defendant’s impairment. We agree with the court’s

reasoning and conclusion. To be relevant, evidence need only have “any tendency to

make a fact more or less probable than it would be without the evidence.” Ariz. R. Evid.

401. And our supreme court has observed that “[t]his standard . . . is not particularly

high.” State v. Oliver, 158 Ariz. 22, 28, 760 P.2d 1071, 1077 (1988).



partition-ratio evidence is admissible. 202 Ariz. 273, ¶ 18, 43 P.3d at 605. However, we
also discussed partition-ratio evidence generally and favorably cited State v. Hanks, 772
A.2d 1087 (Vt. 2001), which “reached a similar conclusion” in permitting general
partition-ratio evidence. 202 Ariz. 273, ¶¶ 14, 17, 43 P.3d at 604-05.
       8
        According to Cooperman’s expert, the only way to determine a defendant’s
partition ratio at the time of the breath test is to conduct simultaneous blood and breath
tests because “[p]artition ratio is blood divided by breath.”
                                             12
¶22          The state nonetheless maintains that evidence regarding variances in

partition ratios generally should be precluded because it “could only serve to confuse the

issue and[/]or mislead the jury.”    Rule 403 provides that relevant evidence can be

excluded if “its probative value is substantially outweighed by a danger of . . . unfair

prejudice, confusing the issues, misleading the jury, undue delay, wasting time, or

needlessly presenting cumulative evidence.”

¶23          As did the city court, we find Hanks and McNeal instructive. In Hanks, the

Vermont Supreme Court concluded general partition-ratio evidence was admissible in a

prosecution for DWI, similar to our (A)(1) DUI offense, because “any evidence raising a

doubt as to defendant’s condition . . . is relevant.” 772 A.2d at 1092. Although the court

acknowledged the general evidence the defendant sought to admit was “not highly

probative given the unlikelihood that defendant’s partition ratio . . . fell outside the

normal curve,” the court specifically rejected the notion that allowing the evidence would

confuse the jury. Id. The court reasoned:

             Evidence on the variability of partition ratios would simply
             reveal to the jury that the breath-test result is based on a
             statutorily accepted conversion rate that tends to favor
             defendants, but that the result is not unassailable with respect
             to demonstrating impairment. We fail to see how such
             evidence would be confusing to the jury or unduly prejudicial
             to the State; to the contrary, not allowing defendants to reveal
             these scientifically recognized facts would make it difficult, if
             not impossible, for a defendant to challenge a test result that
             is admissible in generic [DUI] prosecutions only as a
             permissive inference on the ultimate question of impairment.




                                            13
Id. at 1093. Similarly, in McNeal, the California Supreme Court approved the use of

general partition-ratio evidence, explaining that all evidence tending to rebut the

presumption of intoxication is admissible. 46 Cal. 4th at 1200.

¶24           We agree with the court in Hanks that although the probative value of

general partition-ratio evidence usually will be low, 772 A.2d at 1092, we cannot say it is

substantially outweighed by the danger of confusing the issues or misleading the jury.

Because the ultimate issue in an (A)(1) case is whether the defendant was driving while

“under the influence of intoxicating liquor,” § 28-1381(A)(1), evidence showing the

Intoxilyzer may have overstated a defendant’s alcohol concentration, and thus his

impairment, could be an important part of the defense, especially if the defendant tested

at or near the .08 threshold. Cf. Fuenning v. Superior Court, 139 Ariz. 590, 598, 680

P.2d 121, 129 (1983) (defendant may offer expert testimony to show “for one reason or

another” test results did not establish DUI). Although the Intoxilyzer produces accurate,

even understated, results in most cases, State v. Velasco, 165 Ariz. 480, 485, 799 P.2d

821, 826 (1990), a defendant charged under § 28-1381(A)(1) nonetheless is entitled to

introduce reliable evidence challenging the state’s alcohol-concentration evidence in his

particular case.9


       9
        The state also argues, in passing, that the expert’s testimony “is scientifically
invalid and fails to meet the foundational requirements of Rule 702[, Ariz. R. Evid.].”
This argument was not raised in the state’s motion in limine or in its petition for special
action; accordingly, it is waived on appeal. State v. Lopez, 170 Ariz. 112, 117, 822 P.2d
465, 470 (App. 1991). Moreover, the argument is unsupported by reference to relevant
legal authority. See Ariz. R. Civ. App. P. 13(a)(6) (brief shall include “[a]n argument
which shall contain the contentions of the appellant with respect to the issues presented,
and the reasons therefor, with citations to the authorities, statutes and parts of the record
                                             14
¶25           Accordingly, we hold that when a defendant is charged with DUI under

§ 28-1381(A)(1) and the state introduces evidence of his breath-alcohol concentration at

trial, he may offer evidence explaining how partition ratios vary within an individual and

among the general population and how that variability may result in breath-test results

that overstate a defendant’s actual level of intoxication. It is then for the jury to decide

the weight to be given such evidence in the particular case. See State v. Williams, 209

Ariz. 228, ¶ 6, 99 P.3d 43, 46 (App. 2004) (“Although the record contains some

conflicting evidence, it was for the jury to weigh the evidence and determine the



relied on”); State v. Carver, 160 Ariz. 167, 175, 771 P.2d 1382, 1390 (1989) (“opening
briefs must present significant arguments” and “[f]ailure to argue a claim usually
constitutes abandonment and waiver of that claim”). And, even if the argument had been
raised properly, we disagree. Our conclusion that general partition-ratio evidence is
admissible in an (A)(1) case is consistent with Rule 702, which provides that “[a] witness
who is qualified as an expert by knowledge, skill, experience, training, or education may
testify in the form of an opinion or otherwise if” the testimony would assist the trier of
fact and is sufficiently reliable. The comments to that rule provide in part:

                      The trial court’s gatekeeping function is not intended
              to replace the adversary system.           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.

                     A trial court’s ruling finding an expert’s testimony
              reliable does not necessarily mean that contradictory expert
              testimony is not reliable. The amendment is broad enough to
              permit testimony that is the product of competing principles
              or methods in the same field of expertise. Where there is
              contradictory, but reliable, expert testimony, it is the province
              of the jury to determine the weight and credibility of the
              testimony.

Ariz. R. Evid. 702 cmt. 2012 amend.

                                             15
credibility of the witnesses.”). We also reaffirm Guthrie’s holding that partition-ratio

evidence is inadmissible in an (A)(2) case and agree with the city court that the state is

entitled to a limiting instruction to that effect.10 We find no abuse of discretion in the

superior court’s denial of relief.

Hematocrit, Breathing Patterns, and Breath and Body Temperature

¶26           Finally, the state argues that evidence of the possible effect on breath tests

of hematocrit, breathing patterns, and breath and body temperature should be excluded in

both (A)(1) and (A)(2) cases unless the defendant can offer evidence of his own

physiology at the time of the test. The state maintains the possibility these factors could

affect the breath test is not relevant because it “has no basis in fact—as applied to this

defendant.” To support its argument, the state asserts the experts agreed that “blood

hematocrit (blood concentration) was irrelevant to the issue of what might affect the

differences between contemporaneous breath and blood tests”; a properly administered

test—one in which the subject is instructed to take a deep breath and blow into the

machine as long as he can—would “negate” any potential effect breathing patterns could

have on the test results; and one study had found “no direct correlation shown between


       10
          Our holding is consistent with evidentiary rulings in other cases allowing
general, as opposed to case-specific, evidence. See, e.g., State v. Chapple, 135 Ariz. 281,
292, 296-97, 660 P.2d 1208, 1219, 1223-24 (1983) (expert testimony regarding general
reliability of eye-witness identification admissible without any opinion regarding
accuracy of specific identification made by witnesses); State v. Gonzalez, 229 Ariz. 550,
¶ 16, 278 P.3d 328, 332 (App. 2012) (expert testimony regarding “general practices of
drug organizations” relevant and admissible); State v. Tucker, 165 Ariz. 340, 346, 798
P.2d 1349, 1355 (App. 1990) (expert witness may testify as to general characteristics and
behavior of sex offenders and victims if information not within knowledge of lay
persons).
                                            16
body temperature, breath temperature and the effect it would have on simultaneous breath

and blood tests for alcohol concentration.”

¶27           But quoting State ex rel. McDougall v. Superior Court, 178 Ariz. 544, 546,

875 P.2d 203, 205 (App. 1994), Cooperman contends a “defendant may attack the

accuracy of a breathalyzer on any relevant ground, including the inherent margin of

error.” He claims “evidence of temperature and breathing patterns are independent of

partition ratio . . . [and] are always relevant and admissible in challenging the § 28-

1381(A)(2) charge,” and “requiring the defendant to provide specific evidence of

independent physiological variables is improper burden shifting.”

¶28           As noted above, evidence is relevant if it has “any tendency to make a fact

more or less probable.” Ariz. R. Evid. 401. In reaching its conclusion that evidence of

these physiological variables is relevant and admissible in both types of cases—even

without defendant-specific evidence—the city court necessarily rejected the opinion of

the state’s expert and, instead, relied upon the testimony of defense expert Flaxmayer.

Although Sloneker testified that hematocrit “doesn’t make any difference in the

simultaneous breath/blood comparisons” based on the results of one study, Flaxmayer

opined that “hematocrit can change [either breath or blood alcohol concentration] by

about plus or minus five percent” based on the results of a different study. Where the

experts’ testimony differed, it was within the court’s discretion to reject Sloneker’s

opinion. State v. Ellison, 213 Ariz. 116, ¶ 32, 140 P.3d 899, 911 (2006).

¶29           Flaxmayer also testified that “how you breathe and how you blow into the

instrument changes the reading that you obtain on the instrument. It changes your breath

                                              17
alcohol concentration.” As to temperature, he stated that “[t]he amount of alcohol that

leaves the blood is a function of [body] temperature”; that studies have shown a

statistically significant difference in the breath temperature among participants; that

breath machines were calibrated to thirty-four degrees centigrade and that one degree

above or below that level could result in a six-to-eight-percent change in the breath-test

result. He stated:

              [T]emperature affects the amount of alcohol in your breath.
              Your breathing affects the amount of alcohol in your breath,
              regardless [of] if you then take the additional step to use [the]
              partition ratio to make the calculation. It changed what was
              in your breath.

¶30           The city court noted that Sloneker “did not address this exact issue” of how

breathing patterns and temperature may affect breath alcohol readings, other than to state

that these factors were related to the partition ratio. And although Flaxmayer agreed that

if an individual takes a deep breath and blows into the machine as instructed it should

cancel out the potential physiological effects, he also testified “you can’t always tell if

somebody’s breathing exactly as instructed.” In sum, Cooperman presented competent

expert testimony that these physiological factors, apart from partition-ratio evidence, can

impact the ability of the machine to accurately register a defendant’s breath alcohol

concentration, which is relevant to both charges.       The court thus did not abuse its

discretion in concluding the evidence had some tendency to make a fact in issue more or

less probable. Cf. State v. Storholm, 210 Ariz. 199, ¶¶ 11-12, 109 P.3d 94, 96 (App.

2005) (defendant has right to obtain blood test to “cast doubt on the validity of the breath

alcohol concentration results”); Moss v. Superior Court, 175 Ariz. 348, 352, 857 P.2d

                                             18
400, 404 (App. 1993) (accuracy of breath readings means due process does not require

state to preserve breath sample for independent testing; “focus inherently shifts from the

breath sample to the machine itself and its proper operation”).

                                        Disposition

¶31           For the reasons stated above, the superior court’s ruling is affirmed.


                                                 /s/ Garye L. Vásquez
                                                 GARYE L. VÁSQUEZ, Presiding Judge

CONCURRING:


/s/ Virginia C. Kelly
VIRGINIA C. KELLY, Judge


/s/ Peter J. Eckerstrom
PETER J. ECKERSTROM, Judge




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