Mr. Eisenberg. I hand you Commission Exhibit 557, which also consists of—which consists of two expended shells, and I ask you whether you are familiar with them.
Mr. Nicol. Yes, sir. These are the specimens, the two shells which I used as standards or tests to compare against the other three fired cartridge cases.
Mr. Eisenberg. And you obtained those from what source?
Mr. Nicol. I obtained these from Mr. Eisenberg on the 24th of March here in this office.
Mr. Eisenberg. Again for the record, I obtained these shells from the FBI and turned them over directly to Mr. Nicol, and they have been identified earlier as having been fired by the FBI from Exhibit 139, the rifle found on the sixth floor of the TSBD building.
Now, Mr. Nicol, did you examine the shells in Exhibits 543, 544, and 545 to determine whether they had been fired from the same rifle as fired the shells in Exhibit 557?
Mr. Nicol. Yes; I did.
Mr. Eisenberg. And what was your conclusion?
Mr. Nicol. Based upon the similarity of the firing-pin impressions and the breech-block markings, as well as ejector and extractor marks, it is my opinion that all three of the exhibits, 545, 543, and 544, were fired in the same weapon as fired Exhibit 557.
Mr. Eisenberg. Mr. Nicol, did you take photographs of the various shells under the microscope?