Case (cite)
State v. Campbell, 239 N.W. 715 (Iowa 1931)
Note: there are long excerpts in the opinion from the expert’s testimony and the questions he was asked.
“id that portion of the question, asking for the conclusion reached by him from an examination of the pictures and his answer, “The conclusion I reached as a result of a study of these pictures was to the effect that both of these bullets had passed through the same barrel,” invade the province of the jury? We answer in the negative. The jury had the benefit of the expert, scientific study, special training, knowledge, skill, and experience of the witness, and a full explanation of the exhibits. The theory upon which testimony, such as was given by the witness Goddard, is admissible, is that the subject–matter of the inquiry is so peculiarly within the range of scientific knowledge or special training and skill that to exclude it would work a denial of the only proof competent to establish the fact. ”
The conviction or conclusion of an expert or skilled witness is, after all, only his belief, his opinion, or best judgment. The question objected to did not ask for the fact as to whether or not the two bullets passed through the same barrel, and neither did the answer state as a fact that the two bullets passed through the same barrel. The fact was left for the determination of the jury, taking into consideration the opinion of the witness Goddard upon the subject and the credibility which the jury saw fit to give to him as a skilled or expert witness. In Evans v. Commonwealth, 230 Ky. 411, 19 S.W.(2d) 1091, 1096, 66 A. L. R. 360, the court, in passing upon this proposition, said: “The statement made by this witness of which the defendant is complaining was this: ‘I am convinced as a result of this test that the bullet in evidence was fired through the pistol in evidence 376281.’ A reading of that answer shows the witness did not state that as a fact, but stated that, from his observation, he was convinced. In other words, he stated that as his opinion.”
The witness Goddard, as shown by his testimony, has made a special study of and is experienced in the subjects concerning which he was interrogated and is shown to have had suitable instruments and equipment with which to make the test inquired about, and therefore, as such expert or skilled witness, his opinion upon the subject of inquiry is competent, a rejection of which would be a serious impairment of the rights of the state in the investigation of truth.