Guthrie v. Jones
In Guthrie v. Jones, 202 Ariz. 273,2, 43 P.3d 601, 602 (App. 2002), the Court held that evidence regarding breath-to-blood partition ratios 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, the Court 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.