State v. Eighth Judicial District Court ex rel. County of Clark
267 P.3d 777
Nev.2011Background
- Armstrong charged with DUI causing death/substantial bodily harm under NRS 484C.430(1) on two theories: under the influence and at or above .08 BAC while driving.
- Collision occurred about 1:30 a.m.; a single blood sample was drawn at 3:51 a.m. with BAC 0.18.
- Motion to exclude the blood test argued it was taken outside the two-hour statutory window and relied on a single sample; retrograde extrapolation was argued to be unreliable and unfairly prejudicial.
- State contended retrograde extrapolation was not required to prove BAC at the time of driving and, if used, its variables go to weight, not admissibility; blood test also relevant to DUI.
- District court partially granted Armstrong’s motion: excluded retrograde extrapolation and the numerical result but allowed generalized evidence that the blood test showed presence of alcohol.
- Nevada Supreme Court denied mandamus relief, holding retrograde extrapolation is relevant but may be unfairly prejudicial under the circumstances; decision to admit or exclude turns on case-specific reliability and prejudice considerations.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| May retrograde extrapolation be admitted where only one post-incident blood sample exists? | Armstrong argues factors known render extrapolation reliable; single sample can be sufficient. | State argues extrapolation not required; if used, reliability issues affect weight not admissibility. | No manifest abuse; extrapolation may be unfairly prejudicial under these facts; petition denied. |
| Whether the district court properly balanced probative value against unfair prejudice under NRS 48.035. | Extrapolation evidence is probative of BAC at driving time and should be admitted. | Variables and single sample undermine reliability; prejudice outweighs probative value. | Court did not err; in these circumstances, prejudice outweighed probative value; admissibility denied. |
Key Cases Cited
- Mata v. State, 46 S.W.3d 902 (Tex. Crim. App. 2001) (guidance on factors affecting reliability of extrapolation; balancing required)
- Sheriff v. Burcham, 198 P.3d 326 (Nev. 2008) (recognizes relevance of retrograde extrapolation to DUI theories in Nevada)
- Anderson v. State, 865 P.2d 318 (Nev. 1993) (discusses retrospective evidence in DUI context)
- Old Chief v. United States, 519 U.S. 172 (1997) (explains unfair prejudice concept in Rule 403 context)