Monday, December 9, 2013

Expert Testimony on Reliability of Breath Test in DUI Excluded

The California Supreme Court affirmed a trial court decision that excluded the defendant's expert witness testimony regarding the reliability of breath test machines at trial.

The court ruled as follows:

"The trial court did not err in limiting Dr. Hlastala‟s prehearing jury testimony and excluding his subsequently proposed elaborating testimony with respect to the statutory per se charge. As the trial court observed, defendant remained free to argue, and present evidence, that the particular machines used in this case malfunctioned, or that they were improperly calibrated or employed. But as explained earlier, the 0.08 percent breath-alcohol concentration formulated by the Legislature in enacting the underlying per se offense, section 23152(b), was adopted on the basis of correlation studies employing just such breath-testing
machines — and the various physiological factors that affect the results of breath machines generally, have already been taken into account by those studies and the widely accepted statutory partition ratio. We construe both the statute, section 23152(b), and the regulation on which defendant relies, California Code of
Regulations, title 17, section 1219.3, as calling simply for a breath specimen . . . " People v. Vangelder, Cal.Sup. C.t; Nov 21, 2013; S195423, at 51-52.

This case presents a blow to an otherwise-great expert defense in breath test DUIs!