THE PEOPLE, Plaintiff and Respondent, v. DONALD E. BRANSFORD et al., Defendants and Appellants, 8 Cal. 4th 885

Opinion MOSK, J. We granted review in these consolidated matters to consider whether the trial court should have allowed defendants convicted of driving with 0.08 percent or more of alcohol in their blood to challenge their breath-test results by showing that their personal ratio of breath-alcohol concentration to blood-alcohol concentration (the “partition ratio”) differed from the standard partition ratio that breath-testing machines use to convert breath-alcohol readings into blood-alcohol equivalents.

As will appear, we conclude the trial court correctly excluded such evidence, and we therefore affirm the judgment of the Court of Appeal to that effect. Defendant Donald E. Bransford was arrested for drunk driving on August 18, 1991. He took a breath test, which showed a blood-alcohol concentration of 0.09 percent. A jury convicted him on October 22, 1992, of violating former Vehicle Code

section 23152, subdivision (b) (hereafter

section 23152(b)), i.e., driving a vehicle while having 0.08 percent or more, by weight, of alcohol in the blood. Defendant Ralph Maldonado was arrested on or about June 27, 1991. Although the record does not specifically so state, he also took a breath test. He was convicted on September 24, 1991, of violating

section 23152(b). Both defendants contended on appeal to the appellate department of the superior court and, following certification, to the Court of Appeal that the trial court improperly excluded the above described evidence of their personal partition ratios. The Court of Appeal rejected the contention and affirmed the judgments. In Burg v.

Municipal Court (1983) 35 Cal.3d 257 [198 Cal.Rptr. 145, 673 P.2d 732] (Burg), we reviewed the history of the Legislature’s initial responses to the problem of drunk driving, and upheld the first California statute to criminalize the act of driving with a specified percentage of alcohol in the blood. We held that the statute defined the “new and separate offense” of driving with a prohibited blood-alcohol concentration (35 Cal.3d at p. 265), and that it was a valid exercise of the police power and was not void for vagueness (id. at pp. 266-273).

In 1989, in the immediate predecessor to the statute under which defendants were convicted, the Legislature lowered the prohibited blood-alcohol concentration from 0.10 percent to 0.08 percent. Because the statute continued to define the offense solely in terms of “grams of alcohol per 100 milliliters of blood,” the prosecution continued to convert breath-test results into equivalent readings per 100 milliliters of blood.

The relevant regulation of the Department of Health Services required that such conversion use a standard partition ratio treating the amount of alcohol per 210 liters of breath as equivalent to the amount of alcohol per 100 milliliters of blood. (Cal. Code Regs., tit. 17, § 1220.4, subd. (f).) Many variables, however, can affect the actual ratio of an individual’s breath-alcohol concentration to blood-alcohol concentration.

These variables include body temperature, atmospheric pressure, medical conditions, sex, and the precision of the measuring device. (Thompson, The Constitutionality of Chemical Test Presumptions of Intoxication in Motor Vehicle Statutes (1983) 20 San Diego L.Rev. 301, 327; Annot. (1991) 90 A.L.R.4th 155, 160.) Changes in these variables may result in a difference between an individual’s actual blood-alcohol level and the blood-alcohol level determined by applying the standard partition ratio to the breath-test results.

Courts therefore allowed defendants charged under the predecessor statute to attack breath-test results on the basis of this variability. Defendants were initially allowed to demonstrate only that their personal partition ratio differed from the standard partition ratio. (See, e.g., People v. Pritchard (1984) 162 Cal.App.3d Supp. 13, 17 [209 Cal.Rptr. 314]; People v. Herst (1987) 197 Cal.App.3d Supp. 1, 3-4 [243 Cal.Rptr. 83].) They would do so by simultaneously measuring their breath-alcohol concentration and blood-alcohol concentration over a period of time. (See, e.g., People v.

Cortes (1989) 214 Cal.App.3d Supp. 12, 21 [263 Cal.Rptr. 113] (Cortes); People v. Lepine (1989) 215 Cal.App.3d 91, 94 [263 Cal.Rptr. 543] (Lepine).) Later courts also allowed defendants to demonstrate that partition ratios differ among individuals generally. (See, e.g., Lepine, supra, 215 Cal.App.3d at p. 101.) Defendants would usually do so by having an expert testify that the standard partition ratio is merely an approximation and that different individuals have different personal partition ratios. (See, e.g., Lepine, supra, 215 Cal.App.3d at p. 101; Cortes, supra, 214 Cal.App.3d at p.

Supp. 19.) Defendants here, however, were convicted under

section 23152(b), not its predecessor.

By the time of their arrests, the Legislature had amended the predecessor statute by adding the following italicized language: “It is unlawful for any person who has 0.08 percent or more, by weight, of alcohol in his or her blood to drive a vehicle. “For purposes of this subdivision, percent, by weight, of alcohol in a person’s blood shall be based upon grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath.” (Stats. 1990, ch. 708, § 1, italics added.) Speaking largely through their amici curiae, defendants briefly contend the amendment made no substantive change to the predecessor statute but merely codified the existing administrative definition of the standard partition ratio. (Cal.

Code Regs., tit. 7, § 1220.4, subd. (f).) They argue that

section 23152(

b) on its face continued to define the offense in terms of blood-alcohol concentration, and urge that the addition of the phrase, “in a person’s blood,” in the second paragraph reinforces this reading. Although the statute did specify that percent, by weight, of alcohol “shall be based on” grams of alcohol per 210 liters of breath, defendants argue that this phrase merely provided an alternate means for calculating the blood-alcohol concentration.

Although it is possible to read the statute this way, we believe there is instead only one reasonable manner in which to do so, i.e., the Legislature intended the statute to criminalize the act of driving either with the specified blood-alcohol level or with the specified breath-alcohol level. The second paragraph provided two distinct

definitions, “For purposes of this subdivision,” of the phrase, “percent, by weight, of alcohol in a person’s blood.” (Stats. 1990, ch. 708, § 1.) Under the second definition—i.e., “grams of alcohol per 210 liters of breath”—section 23152(

b) prohibited the act of driving with 0.08 percent or more of blood alcohol as defined by grams of alcohol in 210 liters of breath. The Legislature originally considered the addition of the phrase, “or grams of alcohol per 210 liters of breath,” while enacting the bill that became the version of

section 23152(

b) effective January 1, 1992. (Sen. Bill No. 1119 (1989-1990 Reg. Sess.) §25, enacted as Stats. 1989, ch. 1114, §25, p. 4079.) Although the legislative history of that bill only briefly discusses the Legislature’s reason for the change, one legislative digest does state that the bill would “Define [blood-alcohol concentration] as alcohol concentration expressed in . . . grams of alcohol per 210 liters of breath.” (Assem. Com. on Pub. Safety, Dig. of Sen. Bill No. 1119 (1989-1990 Reg. Sess.), as amended May 15, 1989, p. 3, italics added and deleted.) The legislative history of the bill that became the version of

section 23152(

b) under which defendants were convicted (Assem. Bill No. 4318 (1989-1990 Reg. Sess.), enacted as Stats. 1990, ch. 708, § 1) lends further support to this

interpretation. For example, the Court of Appeal buttressed with a legislative analysis of the bill its conclusion that

section 23152(

b) criminalized driving with either the stated blood-alcohol or breath-alcohol level. That analysis characterized the “key issue” of the bill as whether driving under the influence should “be statutorily defined in terms of the concentration of alcohol found in the breath when breath analysis is used.” (Sen. Com. on Judiciary, Analysis of Assem. Bill No. 4318 (1989-1990 Reg. Sess.) p. 1, italics added.) It observed that attacks by defendants on the partition ratio “result in expensive and time consuming evidentiary hearings and undermine successful enforcement of driving under the influence laws.” (Sen.

Com. on Judiciary, Analysis of Assem.

Bill No. 4318, supra, at p. 2.) It stated that the amendments would “eliminate the need for conversion of a breath quantity to a blood concentration of alcohol. . . .” (Id. at p. 1, italics added.) To read the statute to allow the prosecution to establish the offense solely by proof of a prohibited breath-alcohol level, moreover, promotes the state’s interest in reducing the danger to the public caused by those who drink and drive. (See Burg, supra, 35 Cal.3d at pp. 261-262.) It will increase the likelihood of convicting such a driver, because the prosecution need not prove actual impairment. (American Bar Association Criminal Justice Section, Rep., Drunk Driving Laws and Enforcement (1986) p. 31.) Adjudication of such criminal charges will also require fewer legal resources, because fewer legal issues will arise. (Id. at p. 32.) And individuals prosecuted under such a statute will be less likely to contest the charge. (Ibid.) It is true the Legislature could have drafted the statute more clearly. (E.g., U.

Veh. Code (1992 rev.) § 11-902, subd. (a)(1); State v. McManus (1989) 152 Wis.2d 113 [447 N.W.2d 654, 657] [former Wisconsin statute].) Nevertheless, we hold as we did in Burg, supra, 35 Cal.3d at page 265, that

section 23152(

b) defined a particular type of prescribed conduct: it set forth an alternative definition of the offense of driving with a prohibited blood-alcohol concentration, i.e., driving with 0.08 percent or more of blood alcohol as defined by grams of alcohol in 210 liters of breath. Defendants contend

section 23152(

b) unconstitutionally created an irrebuttable conclusive presumption that the amount of alcohol in 210 liters of breath was equivalent to the amount of alcohol in 100 milliliters of blood. (See Ulster County Court v. Allen (1979) 442 U.S. 140 [60 L.Ed.2d 111, 99 S.Ct. 2213]; Sandstrom v. Montana (1979) 442 U.S. 510 [61 L.Ed.2d 39, 99 S.Ct. 2450].) In Burg, supra, 35 Cal.3d 257, we rejected a similar challenge to the predecessor to

section 23152(b), which set forth the then-new offense of driving with a blood-alcohol level of 0.10 percent or more. We held that the statute “does not create a conclusive presumption of intoxication .... Instead, the statute defines, in precise terms, the conduct proscribed.” (35 Cal.3d at p. 265.) We observed that “In other states that have enacted a statute similar to

section 23152, subdivision (b), the courts have drawn the same conclusion, notably the Washington Supreme Court which declared, ‘The statute does not presume, it defines.’ (State v. Franco (1982) 96 [Wn.2d] 816 [639 P.2d 1320, 1323]; see also State v. Abbott (1973) 15 Ore.App. 205 [514 P.2d 355, 357] [question is not whether defendant is intoxicated, but whether he had the specified level of alcohol in his blood]; State v. Gerdes (S.D. 1977) 252 N.W.2d 335, 335-336 [by proscribing driving with 0.10 percent blood alcohol, the legislature is ‘stating an offense’]; cf. People v.

Dillon (1983) 34 Cal.3d 441, 472-476 [194 Cal.Rptr. 390, 668 P.2d 697] [Pen. Code, § 189 does not presume malice; it defines first degree felony murder as an offense in which malice is not an element].” (Ibid.) Similarly, here

section 23152(

b) did not presume that the driver was intoxicated or “under the influence”; instead, it defined the substantive offense of driving with a specified concentration of alcohol in the body. Thus, it did not create an irrebuttable conclusive presumption. Defendants also contend

section 28, subdivision (d), of

article I of the California Constitution—declaring that trial courts shall not exclude “relevant evidence” from criminal trials except as provided by statute—mandated that this evidence be admissible. But evidence of the variability of partition ratios was not relevant evidence because, once again,

section 23152(

b) defined the offense without regard to such ratios. Defendants further contend the court’s refusal to consider evidence of the variability of partition ratios denied them their rights to confrontation and counsel under the Sixth Amendment to the United States Constitution. It is clear, however, that “The accused does not have an unfettered right [under the Sixth Amendment] to offer testimony that is incompetent, privileged, or otherwise inadmissible under standard rules of evidence.” (Taylor v. Illinois (1988) 484 U.S. 400, 410 [98 L.Ed.2d 798, 811, 108 S.Ct. 646].) Because

section 23152(

b) defined the offense on the basis of grams of alcohol per 210 liters of breath, the court correctly ruled such evidence irrelevant and therefore inadmissible. Moreover, defendants remained free to challenge the breath-test results on other, relevant grounds, including the reliability of the machine and the manner in which the test was administered. The judgment of the Court of Appeal is affirmed. Lucas, C. J., Arabian, J., Baxter, J., George, J., and Werdegar, J., concurred. All statutory references are to this code unless otherwise specified.

The statute made it unlawful for any person “who has 0.10 percent or more, by weight, of alcohol in his or her blood to drive a vehicle . ... [SO For purposes of this subdivision, percent, by weight, of alcohol shall be based upon grams of alcohol per 100 milliliters of blood.” (Stats. 1981, ch. 940, § 33, p. 3578.) The statute thus made it unlawful for any person “who has 0.08 percent or more, by weight, of alcohol in his or her blood to drive a vehicle. [<][] For purposes of this subdivision, percent, by weight, of alcohol shall be based upon grams of alcohol per 100 milliliters of blood.” (Stats. 1989, ch. 479, § 3, p. 1691.) The regulation is actually written in terms of the amount of alcohol in 2,100 milliliters of breath and the amount of alcohol in 1 milliliter of blood.

In 1989, the Legislature enacted, effective January 1, 1992, the successor to the statute under which defendants were convicted. (Stats. 1989, ch. 1114, §25, p. 4079.) The phrase, “or grams of alcohol per 210 liters of breath,” first appeared there. The Legislature enacted the statute under which defendants were convicted after it enacted the successor statute (Stats. 1990, ch. 708, § 1); that statute also contained the quoted phrase. Although the statute under which defendants were convicted remained in effect only until January 1, 1992, essentially the same language is in force today.

See also Assembly Committee on Public Safety, Digest of Assembly Bill No. 4318 (1989-1990 Reg. Sess.) page 2 (“statutorily defining driving under the influence of alcohol in terms of the concentration of alcohol found in the breath when breath analysis is used”); Assembly Office of Research, third reading analysis of Assembly Bill No. 4318 (1989-1990 Reg. Sess.) page 1 (“statutorily defin[es] driving under the influence of alcohol in terms of the concentration of alcohol found in the breath”); Senate Rules Committee Analysis of Assembly Bill. No. 4318 (1989-1990 Reg. Sess.) page 1 (same).

See also Assembly Committee on Public Safety, Digest of Assembly Bill No. 4318, supra, page 2 (“Eliminate the need for conversion of a breath quantity to a blood concentration of alcohol”); Assembly Office of Research, third reading analysis of Assembly Bill No. 4318, supra, page 1 (same); Senate Rules Committee, Analysis of Assembly Bill No. 4318, supra, page 1 (same). Amicus curiae observe that the Legislative Counsel’s Digest refers to “conforming changes.” (See Legis. Counsel’s Dig., Assem. Bill No. 4318 (1989-1990 Reg.

Sess.).) They argue that the quoted phrase proves the Legislature merely added for the sake of consistency the phrase, “or grams per 210 liters of breath,” to the language that referred only to milliliters of blood; they suggest it did so to simplify the conversion from breath-alcohol to blood-alcohol concentration, but they fail to explain how this incorporation simplifies the conversion. They also assert the Legislature believed the federal government required states to statutorily—as opposed to administratively—define the partition ratio, but they offer no support for this claim.

The Uniform Vehicle Code provides in the cited

section that a person shall not drive a vehicle when “The alcohol concentration in such person’s blood or breath is 0.08 or more based on the definition of blood and breath units in [the definition section] . . . .” (U. Veh. Code, § 11-902, subd. (a), italics added.) The definition

section provides that “Alcohol concentration shall mean either grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath.” (Id., § 11-903, subd. (a)(5), italics added.) Although Illinois’s drunk driving statute is worded differently, the court in People v. Capporelli (1986) 148 Ill.App.3d 1048 [103 Ill.Dec. 864, 502 N.E.2d 11] interpreted it similarly.

That court held that “The statute has provided two ways to measure the level of blood alcohol concentration; one by blood, by means of a blood test; the other by breath, by means of a breathalyzer test.” (Id. at p. 14.) In their brief in this court defendants raise several additional issues. They make an equal protection argument. They also claim that “an erroneous conversion of an accurate breath-alcohol test resulted in an inaccurate blood-alcohol test,” presumably implying the trial court should have allowed them to demonstrate that error. And they contend that under Penal Code

section 1020—providing that matters of fact tending to establish a defense are admissible on a guilty plea—they should have been allowed to present evidence of their personal partition ratios. Defendants did not timely raise these issues in the Court of Appeal. (Cal.

Rules of Court, rule 29(b)(1).) Defendant Maldonado, who was also convicted of driving under the influence of alcohol (§ 23152, subd. (a)), contends the court’s failure to allow into evidence the fact of the variability of partition ratios converted the permissive presumption set forth in the standard instruction on the inference of intoxication (CALJIC No. 12.61 (5th ed. 1994 pocket pt.) p. 74) into an impermissible mandatory presumption. Because he failed to complain in a petition for rehearing that the Court of Appeal opinion did not discuss this issue, we do not address it. (Cal.

Rules of Court, rule 29(b)(2).)