Mr. McCloy. It may be admitted.
Mr. Eisenberg. That will be 561.
(The item identified as Commission Exhibit No. 561 was received in evidence.)
Mr. Eisenberg. Could you proceed with the discussion of the circled marks on this photograph, number 561?
Mr. Frazier. In the case of firing-pin impressions which are shown on Exhibit 561, the marks result from two related sources; excuse me, not sources, but from two related causes, one being the force given to the firing pin driving it into the primer to set off the cartridge, and the second being the force of the powder charge inside the cartridge being driven back—driving the primer back against the firing pin at the same time, so that the metal of the primer is caused to flow or be stamped by the firing pin and pressed against by the gases, so that any irregularities in the firing pin will be impressed into the primer of the cartridge case.
Number 1 consists of a double horizontal line, one a fairly wide coarse line at the top. Immediately under that approximately one-eighth of an inch is a fairly fine horizontal line.
Circled and marked number 2 is a very coarse, wide ridge, very short in length, approximately one-half an inch, and an eighth to a quarter of an inch in height. This ridge is formed by two grooves, a straight groove across the top, and a curved or crescent-shaped groove across the bottom.
Number 3 is a circle drawn around two small raised areas in the primer metal separated by a depression.
Number 4 is a section from a large ridge across the metal of the primer, which has a break in its surface in the lower portion of the circle, and immediately above the break is a groove, and immediately above that again is another ridge which is at a little steeper angle upwards to the left.
Number 5 is a depression, is a portion of a depression appearing at the bottom of the circle with a very short ridge running horizontally across the circle.