Mata v. State

Summary

The Texas Court of Criminal Appeals held that expert testimony using retrograde extrapolation to estimate a defendant's blood alcohol concentration at the time of driving did not satisfy the reliability requirements of Texas Rule of Evidence 702, Daubert, and Kelly. The court focused on the variability of alcohol absorption and elimination and the expert's inconsistent and unsupported assumptions regarding the defendant's BAC. The court also held that the defendant preserved his challenge to the reliability of the expert testimony.

Holdings

1. Mata preserved error because he timely informed the trial court that he sought to exclude the expert's testimony as unreliable, and his complaint was stated with sufficient specificity.
2. Retrograde extrapolation may be reliable in an appropriate case, but the proponent must establish by clear and convincing evidence that the expert reliably applied the underlying science and clearly and consistently explained it.
3. The trial court abused its discretion by admitting the portion of McDougall's testimony that extrapolated Mata's BAC back to the time of driving because the State failed to prove by clear and convincing evidence that the extrapolation was reliable.

Questions Presented

1. Whether Mata preserved his challenge to the reliability of the expert's retrograde-extrapolation testimony.
2. Whether the expert's retrograde-extrapolation testimony satisfied the reliability requirements of Daubert, Kelly, and Texas Rule of Evidence 702.
3. Whether the trial court abused its discretion by admitting the expert testimony.

Disposition

remanded