Mr. Cunningham. That is approximately 91 times.
Mr. Eisenberg. Are there any dissimilarities on the two—on the test and the suspect cartridge cases, Mr. Cunningham?
Mr. Cunningham. Yes, sir; there are always dissimilarities. However, the similarities so outweigh the dissimilarities that it is an identification. If there are no dissimilarities, I would be suspicious that it would be faked—using the same photograph and just cut and put together.
There are always dissimilarities.
Mr. Eisenberg. Can you explain why there are always dissimilarities when the two cartridge cases are fired in the very same weapon?
Mr. Cunningham. The metal is different; one cartridge case is slightly harder than another; for some reason the cartridge case wasn't driven back, upon firing, into the breech face exactly the same way. In other words, these marks are reproducing, but you don't get exactly the same hit. It would not be possible to get exactly the same hit time after time with different cartridge cases.
Representative Ford. What ratio of similarities and dissimilarities do you have to have?
Mr. Cunningham. There is no ratio. Based upon the examiner's training and experience, he comes to the conclusion that a particular cartridge case or bullet has been fired from a particular weapon. As in this photograph, you can see the dissimilarity is very slight. These are excellent marks.
Representative Ford. There was never any doubt in your mind, then?
Mr. Cunningham. None whatsoever.