Kar’s testimony begins on page 4306 of the reporter’s transcript. Not until page 4394 did defense counsel ask Kar to give his opinion as to whether the paints on the metal post and bubble shield matched each other. Part of the intervening testimony involved the effect of “Bremstrahlung radiation” on electron microscopy of materials. Kar testified that the examiner must adjust for the Bremstrahlung effect, which can mask the presence of certain elements and create spurious indications of other elements. When counsel further asked Kar to “illustrate” the Bremstrahlung effect using a projected graph, the court barred the illustration on its own motion, saying, “I don’t need it illustrated. The jury doesn’t require it. Let’s get the matters that are relevant.”
Kar then testified that the prosecution’s paint comparison expert had apparently not adjusted for the Bremstrahlung effect. When counsel asked Kar if the prosecution examiner’s unadjusted data would lead Kar to the same conclusion he had independently reached about the materials, the court objected that counsel was assuming facts not in evidence: no conclusion about the materials had yet been elicited from Kar. The court told counsel, “Now, I don’t know what his conclusion pertains to, so why don’t we get to it, counsel, please.” As defense counsel began to lay the foundation for Kar’s opinion, however, the court periodically interposed, or solicited from the prosecutor, objections to the phrasing of certain questions. After the court again urged counsel to get to “the bottom line,” the following exchange occurred:
“Q. By Mr. Maple: Do you have an opinion, Dr. Kar, as to whether the paint taken from the—
“The Court: By whom?
“Q. By Mr. Maple: —snap ring of the bubble shield—
“The Court: That he took, right? Not the one that Schliebe took; is that correct?