Mr. Eisenberg. Again there are dissimilar marks on these two pictures, Mr. Frazier?
Mr. Frazier. Yes; there are, for the same reason, that metal does not flow the same in every instance, and it will not be impressed to the same depth and to the same amount, depending on the type of metal, the blow that is struck, and the pressures involved.
Mr. Eisenberg. Is your identification made therefore on the basis of the presence of similarities, as opposed to the absence of dissimilarities?
Mr. Frazier. No, that is not exactly right. The identification is made on the presence of sufficient individual microscopic characteristics so that a very definite pattern is formed and visualized on the two surfaces.
Dissimilarities may or may not be present, depending on whether there have been changes to the firing pin through use or wear, whether the metal flows are the same, and whether the pressures are the same or not.
So I don't think we can say that it is an absence of dissimilarities, but rather the presence of similarities.
Mr. Eisenberg. Any further questions on this cartridge case?
Mr. McCloy. No.
Mr. Eisenberg. Mr. Frazier, you have testified also that you identified the cartridge case which is Exhibit 544 as having been fired from this rifle, in this rifle, to the exclusion of all others. Did you take a photograph of the comparison that you made under the microscope of number 544?
Mr. Frazier. Yes. I again took two photographs, one of the breech-face or bolt-face marks, and one of the firing-pin marks.