People v. Vangelder
58 Cal. 4th 1
Cal.2013Background
- At ~2:30 a.m. defendant was stopped after driving >125 mph; officers detected alcohol odor and administered preliminary breath tests (PAS) showing ~0.095 and 0.086, then post-arrest EC/IR breath tests of 0.08 and blood tests ~0.087–0.088 within three hours. Defendant was charged with DUI (Veh. Code § 23152(a)), per se DUI (Veh. Code § 23152(b)), and speeding over 100 mph.
- Defense expert Dr. Michael Hlastala testified about respiratory physiology: alcohol in bronchial/mucus membranes and factors (breathing pattern, temperature, hematocrit, sex, lung disease) can affect breath samples; he opined breath tests may be inherently inaccurate even when machines work properly.
- Trial court permitted testimony limited to "mouth alcohol" contamination but excluded testimony that properly functioning, approved breath machines generally fail to sample alveolar (deep-lung) air or are unreliable due to the listed physiological factors, treating that testimony as akin to inadmissible partition-ratio variability evidence for a § 23152(b) prosecution.
- Jury convicted on the per se breath count (§ 23152(b)) and the speeding count, deadlocked on the generic DUI (§ 23152(a)). The Court of Appeal reversed the per se conviction; the California Supreme Court granted review.
- The Supreme Court reversed the Court of Appeal, holding the trial court properly excluded the challenged expert testimony as inconsistent with the per se statute and the legislatively/administratively endorsed breath-testing scheme.
Issues
| Issue | Plaintiff's Argument (People) | Defendant's Argument (Vangelder) | Held |
|---|---|---|---|
| Admissibility of expert testimony that breath machines are inherently unreliable because inhalation "saturates" airway so machines do not sample alveolar air | Such testimony conflicts with § 23152(b) as amended and with federal/state certification of approved devices; admission would nullify legislative/administrative determinations | Testimony addresses whether collected breath meets title 17 §1219.3 requirement ("essentially alveolar") and is therefore relevant to per se charge | Excluded: trial court did not err — Legislature/regulations endorse approved devices; breath sample means the end-expiratory sample captured by an approved machine, so testimony inviting juries to reject that policy is inadmissible |
| Admissibility of expert testimony that physiological factors (breathing pattern, temperature, hematocrit, sex, disease) render breath tests unreliable | These factors are encompassed by the statutory conversion/validation process and by certification; permitting such evidence would reintroduce partition-ratio attack barred by Bransford for per se prosecutions | Evidence is not about partition-ratio conversion but about machine sampling accuracy and therefore relevant to per se charge | Excluded: trial court properly treated this as partition-ratio–type evidence and barred it for the § 23152(b) charge |
| Whether defendant may rely on title 17 regulatory compliance to introduce above expert evidence | State adoption and federal conformity lists establish that approved machines reliably sample deep-lung breath; regulatory/legislative scheme precludes relitigation through expert testimony | Defendant may show noncompliance or challenge that a given sample was not "essentially alveolar" under §1219.3 | Held for People: compliance/approval scheme means defendants may challenge malfunction, calibration, or noncompliance in specific cases but cannot use experts to attack the fundamental reliability of approved devices for per se prosecutions |
| Prejudice and right to present a defense (constitutional claim) | Exclusion was proper under state law; defendant could still present evidence of machine malfunction or procedural noncompliance | Exclusion denied due process and compulsory-process rights by preventing defense of per se charge | Denied: no state-law error; exclusion lawful and defendant retained ability to contest calibration/malfunction; conviction affirmed |
Key Cases Cited
- People v. Bransford, 8 Cal.4th 885 (California Supreme Court) (holding partition-ratio variability evidence inadmissible in § 23152(b) per se prosecutions)
- People v. McNeal, 46 Cal.4th 1183 (California Supreme Court) (holding partition-ratio evidence admissible to rebut presumption in § 23152(a) generic DUI prosecutions)
- Burg v. Municipal Court, 35 Cal.3d 257 (California Supreme Court) (upholding per se alcohol statute against vagueness/fair-notice challenges)
- State v. Chun, 943 A.2d 114 (New Jersey Supreme Court) (reviewing partition-ratio science and affirming continued use of 2100:1 ratio)
- State v. Downie, 569 A.2d 242 (New Jersey Supreme Court) (discussing partition-ratio variability and breath/blood correlation studies)
- Brayman v. State, 751 P.2d 294 (Washington Supreme Court) (rejecting due process/equal protection challenges to statutory partitioning and breath test use)