This summary was computer-generated without any editorial revision. It is not official, has not been checked for accuracy, and is NOT citable.
Facts
The Defendant was involved in a vehicular collision that resulted in the death of a passenger in another vehicle. Following the accident, law enforcement officers observed conflicting signs of intoxication in the Defendant, including slurred speech and an unusual odor, but no immediate detection of alcohol. A blood alcohol content (BAC) test conducted six hours after the collision revealed a BAC of 0.04. The State sought to use retrograde extrapolation through an expert witness to estimate the Defendant's BAC at the time of the collision (paras 2-10, 13).
Procedural History
- Trial Court: The Defendant was convicted of vehicular homicide based on a general verdict, which included alternate theories of culpability: driving under the influence of alcohol and reckless driving (paras 11, 21).
- State v. Downey, 2007-NMCA-046: The Court of Appeals affirmed the conviction, holding that the trial court properly admitted the State’s expert testimony on retrograde extrapolation and that any challenges to its reliability went to the weight of the evidence, not its admissibility. A dissenting opinion argued that the expert testimony was unreliable and should have been excluded (paras 22-23).
Parties' Submissions
- Defendant: Argued that the State’s expert witness was not qualified to testify on retrograde extrapolation and that the testimony was unreliable because it was based on unsupported factual assumptions. The Defendant also contended that the admission of this testimony was prejudicial and not harmless (paras 17, 23).
- State: Asserted that the expert witness was qualified and that retrograde extrapolation was a reliable scientific method. The State argued that the expert’s assumptions were reasonable and supported by circumstantial evidence, and that the testimony was properly admitted (paras 16, 19, 36).
Legal Issues
- Was the State’s expert witness qualified to testify on retrograde extrapolation?
- Was the expert testimony on retrograde extrapolation reliable and admissible under Daubert and Alberico?
- Was the improper admission of the expert testimony prejudicial to the Defendant?
Disposition
- The Supreme Court of New Mexico vacated the Defendant’s conviction and remanded the case for a new trial (para 41).
Reasons
Per Maes J. (Chávez CJ., Serna, Bosson, and Daniels JJ. concurring):
Expert Qualification: The Court assumed, without deciding, that the State’s expert witness was qualified to testify on retrograde extrapolation. The Defendant did not meaningfully argue that the trial court abused its discretion in this determination (para 27).
Reliability of Expert Testimony: The Court found that the expert’s testimony was unreliable because it was based on factual assumptions unsupported by the evidence. Specifically, the expert assumed that the Defendant was post-absorptive at the time of the collision, but there was no evidence to confirm when the Defendant had last consumed alcohol. This lack of foundational facts rendered the testimony speculative and inadmissible under Daubert and Alberico (paras 28-34).
Prejudicial Impact: The Court concluded that the improper admission of the expert testimony was prejudicial because it likely influenced the jury’s verdict. The testimony provided the only direct evidence suggesting the Defendant’s BAC exceeded the legal limit at the time of the collision, tipping the balance in favor of the State (para 39).
General Verdict Issue: Because the jury rendered a general verdict, it was impossible to determine whether the conviction was based on the invalid theory of driving under the influence. As a result, the conviction could not stand, and a new trial was required (para 40).