State v. Tanksley, 809 N.W.2d 706

Tanksley was convicted of driving with an alcohol concentration of 0.08 or more under Minn. Stat. § 169.4.20, subd. 1(5).
He moved for a Frye-Mack hearing on the reliability of first-void urine testing to infer urine alcohol concentration's relation to blood alcohol concentration.
Urine sample tested at 8:21 p.m. showed 0.18 g/67 mL; BAC at driving time is not the sole basis for the 0.08 offense.
District court denied the Frye-Mack hearing, ruling urine testing isn’t a novel technique and correlation to BAC isn’t required for the offense.
The trial proceeded as a stipulated-facts trial for the alcohol-concentration offense; under-the-influence charge was dismissed.
Court of Appeals relied on Edstrom but found any error harmless; this court granted review to address the Frye-Mack denial and relevance of first-void urine testing.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Is a Frye-Mack hearing required on first-void urine testing for the 0.08 offense?	Tanksley argues the test is novel and unreliable.	Tanksley contends the district court abused discretion by denying the Frye-Mack hearing.	No Frye-Mack required; correlation to BAC not relevant to the offense.
Is correlation between first-void urine and BAC relevant to proving 0.08 under §169.4.20(1)(5)?	Correlation is needed to prove urine concentration reflects BAC.	Statute allows proving concentration by urine regardless of BAC correlation.	Irrelevant; three authorized methods exist and no requirement to show BAC-urine correlation.
Does the absence of a BAC-BAC correlation affect proof of the two elements of the 0.08 offense?	Urine concentration must align with BAC to prove offense.	Proof required is that urine concentration is 0.08+ within 2 hours.	Not required to prove correlation; sufficient to prove urine concentration meets threshold.
Is the district court’s reliance on Edstrom controlling?	Edstrom supported admitting first-void testing.	Edstrom doesn’t control if issue is not relevant to offense.	This Court’s analysis relies on Horning and statutory structure, not Edstrom.

State v. Horning, 535 N.W.2d 296 (Minn. 1995) (relevance of impairment evidence to the 0.10 offense; two-element proof rule)
State v. Edstrom, 792 N.W.2d 105 (Minn.App. 2010) (approved first-void testing in that case; not dispositive here)
Jacobson v. $55,900 in U.S. Currency, 728 N.W.2d 510 (Minn. 2007) (threshold relevancy standard for admissibility)
Reiter v. Kiffmeyer, 721 N.W.2d 908 (Minn. 2006) (reading statute without adding omitted requirements)
State v. Steward, 645 N.W.2d 115 (Minn. 2002) (relevance of evidence under Rule 401)
State v. Roman Nose, 649 N.W.2d 815 (Minn. 2002) (Frye-Mack framework for admissibility of novel scientific evidence)
Goeb v. Tharaldson, 615 N.W.2d 800 (Minn. 2000) (foundational reliability burden on proponent of scientific evidence)
Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) (test for admissibility of novel scientific evidence)
State v. Mack, 292 N.W.2d 764 (Minn. 1980) (two-pronged Frye-Mack standard adopted)
Frieler v. Carlson Marketing Grp., Inc., 751 N.W.2d 558 (Minn. 2008) (statutory interpretation on legislative change)