337 P.3d 1280
Idaho Ct. App.2014Background
- Trooper stopped Jay Roach for missing front plate and expired rear sticker; trooper detected alcohol odor and Roach failed field sobriety tests and was arrested for DUI.
- After a 15-minute wait, two Intoxilyzer 5000 breath samples read .143 and .144 BAC.
- Defense disclosed Dr. Michael Hlastala as an expert to testify generally that breath tests can be unreliable due to physiological factors (body temperature, breathing pattern, airway vs. alveolar origin of vapor, blood/plasma ratio). He did not opine about Roach’s specific test or machine malfunction.
- The State moved to exclude Hlastala’s testimony; the magistrate excluded it as irrelevant. The district court (sitting as an intermediate appellate court) affirmed the exclusion; Roach appealed.
- The courts held that Idaho’s per se DUI statute requires only the alcohol concentration “as shown by” the approved breath test, so generalized attacks on breath-testing methodology or physiological variability are irrelevant to a per se offense unless targeted to the particular test administration or machine function.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Admissibility of Dr. Hlastala’s expert testimony on physiological factors affecting breath tests | State: Testimony is irrelevant because statute looks to alcohol concentration “as shown by” the breath test | Roach: Testimony shows breath tests can be unreliable and thus is relevant to guilt and to challenging the legislature’s reliance on breath tests | Excluded as irrelevant: generalized scientific critiques of breath testing do not negate a per se result shown by an approved breath test absent a challenge to that specific test or device administration |
| Whether breath test measures alveolar air vs. airway air matters for per se statutory proof | State: Statute requires measurement of “breath,” not alveolar air; machine measures legally cognizable ‘‘breath’’ | Roach: If device measures airway vapor rather than deep-lung air, results overestimate true body alcohol and are relevant | Rejected: Legislature’s per se standard is the alcohol concentration shown by the test (breath) regardless of alveolar/airway distinction |
| Whether physiologic variability is analogous to procedural contamination (15-minute rule) | State: Procedural safeguards address contamination (mouth alcohol); physiologic factors are natural, not contamination | Roach: Variability in breathing/temperature can skew readings like a failure to observe the 15-minute rule | Court: Distinction upheld—physiologic variability is not the type of extrinsic contamination the observation rule guards against; thus not a basis to exclude the per se result |
| Constitutional right to present a complete defense by admitting Hlastala’s testimony | State: Exclusion of irrelevant evidence does not violate due process | Roach: Exclusion deprived him of meaningful opportunity to present a complete defense | Denied: No constitutional violation because defendants have no right to present irrelevant evidence |
Key Cases Cited
- State v. Hardesty, 136 Idaho 707 (Ct. App.) (general challenges to partition ratio irrelevant after statute changed; defendant may still challenge whether device accurately measured that defendant’s breath)
- Elias-Cruz v. Idaho Dep’t of Transp., 153 Idaho 200 (Idaho 2012) (breath-machine margin of error irrelevant at license-suspension hearing because statute looks to concentration as shown by the test)
- State v. Carson, 133 Idaho 451 (Ct. App.) (15-minute observation rule is a procedural safeguard against mouth contamination to ensure validity of breath test)
- Pelayo v. Pelayo, 154 Idaho 855 (Idaho 2013) (standard of appellate review when district court sits in intermediate appellate capacity)
- State v. Hopkins, 113 Idaho 679 (Ct. App.) (previous language suggesting challenges to device methodology and proper administration are permissible)