(concurring specially).
Although I concur in the result the court reaches today, I disagree with the majority’s reasoning with respect to the admissibility of impairment evidence in this case. Contrary to the majority opinion, I am unconvinced that impairment evidence is wholly irrelevant in a prosecution for driving with an alcohol concentration of 0.10 or more in violation of Minn.Stat. § 169.121, subd. 1(d).
First, even though this court has recognized that we should not place undue reliance on outward manifestations of intoxication, see State v. Elmourabit, 373 N.W.2d 290, 292 (Minn.1985), we have never found such evidence so unreliable as to exclude it on that basis alone. For example, in Elmourabit, this court noted “[i]t is not uncommon for a person under the influence of liquor, where judgment or reflexes have been impaired, to nevertheless be able to perform the [dexterity] tests satisfactorily.” 373 N.W.2d at 292. We went on to hold, however, that the results of such tests do have probative value and are one of many items to be weighed by the factfinder. Id. at 293. Moreover, we also have recognized that observable indicia of intoxication are sufficiently reliable in other settings. For example, if Horning had been charged with driving under the influence of alcohol, the state clearly could introduce evidence of impairment to support the charge. See State v. Shepard, 481 N.W.2d 560, 562-63 (Minn.1992). Further, under Minn.Stat. § 169.121, subd. 6 (1994), a peace officer may require a driver to submit to a preliminary screening test when he or she “has reason to believe from the manner in which a person is driving, operating, controlling, or acting upon departure from a motor vehicle, * * * ” that the driver is under the influence of alcohol or a controlled substance. Pursuant to this provision, Minnesota courts frequently have relied on impairment evidence in the context of an officer’s determination of whether to request a driver to submit to a chemical alcohol concentration test. See Costillo v. Commissioner of Pub. Safety, 416 N.W.2d 730, 733 (Minn.1987). Thus, our cases suggest that although impairment evidence may not be conclusive as to an alcohol concentration of 0.10 or more, it is not so unreliable that the factfinder should be precluded, on that basis alone, from receiving the evidence and weighing it accordingly.
Second, although I agree with the majority that driving with an alcohol concentration of 0.10 or more constitutes a separate chargeable offense from driving under the influence of alcohol, I do not agree the factual bases for liability are always exclusive. Minnesota’s criminal DWI statute provides:
Subdivision 1. Crime. It is a crime for any person to drive, operate, or be in physical control of any motor vehicle within this state * ⅜ *:
(a) when the person is under the influence of alcohol;
[[Image here]]
(d) when the person’s alcohol concentration is 0.10 or more;
(e) when the person’s alcohol concentration as measured within two hours of the time of driving is 0.10 or more * * *.
Minn.Stat. § 169.121.
It is an elementary principle of evidentiary law that evidence irrelevant to the state’s burden of proof may nonetheless be relevant for other purposes. In regard to the subd. 1(d) charge, the state had the burden of proving that Horning drove in Stearns County with an alcohol concentration of 0.10 or more. Clearly, as the majority notes, evidence of impairment or lack thereof is irrelevant to the state’s burden because it has no bearing on Horning’s actual alcohol concentration. After the state has established its prima facia case, however, a defendant may *301rebut the state’s evidence or impeach the state’s witnesses with other relevant evidence. It is this critical second step that the majority ignores.
In the present case, the accident giving rise to the Intoxilyzer test occurred at 9:00 p.m., and the trooper administered the test at 11:19 p.m., more than two hours later. The test result indicated that Horning’s alcohol concentration at the time of the test was 0.15. This result, however, is relevant to the charge of driving with a blood alcohol concentration of 0.10 or more only to the extent that it reflects Horning’s alcohol concentration at the time of the accident, more than two hours earlier.1 At trial, the state attempted to establish the necessary link between the test result and Horning’s alcohol concentration at the time of the accident. Using an extrapolation method based on typical alcohol absorption rates and based on an assumption that Horning’s alcohol concentration was falling from the time of the accident to the time of the test, the state’s expert witness estimated Horning’s alcohol concentration was between 0.188 and 0.193 at the time of the accident.
Because the state’s expert did not base his testimony on the results of an Intoxilyzer test administered immediately after the accident, Horning could not attack the results of such a test.2 Instead, the state’s evidence consisted of its expert’s post-accident extrapolation, and Horning was relegated to attacking these extrapolations. Horning therefore challenged the state’s extrapolated estimates by contending that his alcohol concentration was rising from the time of the accident to the time of the test, rather than falling as the state’s expert assumed. To support his contention, Horning sought to admit evidence that he did not appear to be impaired at the time of the accident. This evidence is relevant to his defense that his alcohol concentration was rising because if he showed no clinical signs of intoxication, it is less likely that his alcohol concentration was 0.188 at the time of the accident, it is more likely that his alcohol concentration was rising after the accident, and consequently, it is less likely that Horning’s alcohol concentration was 0.10 or more at the time of the accident. In this situation, whether Horning’s alcohol concentration was above or below 0.10 at the time of the accident is certainly relevant and material to the issue of whether Horning violated this state’s prohibition against driving with an alcohol concentration of 0.10 or more.
We have never required more than a slight probative value in determining relevance, and I find no reason to treat the impairment evidence in this ease differently from any other circumstantial evidence admissible for impeachment purposes. I would limit this holding, however, to situations in which a defendant is charged under Minnesota Statutes section 169.121, subdivision 1(d) and the state offers extrapolation testimony to link the result of a post-driving alcohol concentration test to the defendant’s alcohol concentration at the time of driving. In such a case, impairment evidence offered by the defendant is relevant for the limited purpose of impeaching the state’s extrapolation testimony. Moreover, although I believe the exclusion of impairment evidence was an abuse of discretion, I would conclude the error was harmless. In this case, testimony showed that the Intoxilyzer test was administered properly, the Intoxilyzer machine was operating properly, and the expert believed it produced an accurate and reliable test result. The jury also was presented with a number of credibility issues it presumably resolved in favor of conviction. Moreover, if impairment evidence had been admitted, the state would have introduced additional evidence of insobriety to counter Horning’s lack of impairment. Thus, I would conclude that the trial *302court’s exclusion of the impairment evidence was harmless error.
Notwithstanding, I cannot express more clearly my concern that the majority has, with this opinion, invaded the province of the jury in discarding basic principles of evidence law in favor of a perceived public policy. Clearly, we are presented with a pressing need to eradicate drunk driving in Minnesota. I cannot agree, however, that preventing the jury from performing its duty in weighing otherwise relevant evidence is a proper way to accomplish such a goal.
. Although the majority opinion recognizes that one critical issue is "the chemical testing which determines blood alcohol concentrations,” it fails to discern when Horning's blood chemistry is relevant. That is, the majority opinion fails to recognize that the critical issue is: What was Horning's blood chemistry at the time of the accident?
. Granted, Horning could attack the results of the test conducted more than two hours after the accident occurred, but this test was evidence relating to the charge of having an alcohol concentration of 0.10 or more two hours after driving rather than the charge for which he was convicted.