Opinion ID: 1351466
Heading Depth: 1
Heading Rank: 2

Heading: Refusal to Admit Photographs Supporting Defense Expert Witness

Text: (25) Defendant next contends the trial court erred in refusing to admit two photographs in support of the serological testimony of Dr. Grunbaum, which testimony disputed the reliability of the conventional electrophoresis technique. The photographs purported to permit a comparison between the conventional technique and the Isoelectric Focusing Method recommended by Dr. Grunbaum: they would assertedly have shown that the conventional method produced a configuration of broad, diffuse bands that were difficult to identify, whereas the Isoelectric Focusing Method produced narrow bands that made identification much easier. The prosecutor objected on grounds of relevance, advancing three reasons. First, the method depicted in the photographs was not in fact the same as the method actually used in this case; the results shown in the photographs had been obtained by the Shaler method, which is different from the Wraxall method used by the police technicians here. Second, the blurriness of the photographs did not accurately represent the resolution of the electrophoretic bands to the naked eye, yet the police technicians based their judgment on that resolution. Third, a comparison of the Isoelectric Focusing Method with the conventional electrophoresis technique was not material to the reliability of the latter. The defense countered by citing Dr. Grunbaum's testimony that the Wraxall and Shaler methods produced the same end product. As to the other objections defendant contended, and asserts on appeal, that they go to the weight, not the admissibility, of the evidence. A trial court has wide discretion in determining whether evidence is relevant. ( People v. Green, supra, 27 Cal.3d 1, 19.) A proponent of evidence has the burden of establishing all preliminary facts pertinent to determining the relevancy of that evidence. (Evid. Code, § 403, subd. (a)(1).) A ruling on the admissibility of evidence implies whatever finding of fact is prerequsite thereto; a separate or formal finding is unnecessary unless required by statute. ( Id., § 402, subd. (c).) Applying these principles, we conclude that the trial court did not abuse its discretion in excluding the challenged evidence. Defendant failed to lay an adequate foundation from which the court could determine that the results depicted in the photographs sufficiently resembled those observed in this case by the technicians who used a different method. Although Dr. Grunbaum testified that the two methods produce the same result, he admitted that he had not observed the Los Angeles Police Department's particular method or results. While Dr. Grunbaum may be correct as to the similarity of the methods, it was reasonable for the court to conclude that the similarity between the method depicted in the photographs and the one actually employed had not been sufficiently established. With this crucial factual link missing, the court did not err in concluding that defendant had failed to carry his burden of establishing relevance. As for the photograph depicting the Isoelectric Focusing Method, we agree that it was not material to any issue in this case. The defectiveness of the evidence-gathering techniques in this case, if any, is not measured in comparison to other, purportedly superior methods. Such a comparison cannot assist the jury in determining to what extent the method employed actually produced probative evidence, nor can it help the jury assign a weight to the evidence. It was therefore properly excluded.