Mr. Nicol.

621 is placed in a position corresponding to the arrows, a match of the fine striations, the pairs of broad lines as well as the fine lines, can be seen.
The reason that this could not be taken under the comparison microscope is that because of course we cannot divide the cartridge case, so that this had to be done photographically rather than being done on a comparison basis.
Now, this illustrates the fact that the same operation occurred twice on this particular cartridge case.
Do you want to introduce the third at this time?

Mr. Eisenberg.

Yes.
This is a photograph taken by you?

Mr. Nicol.

Yes, sir.

Mr. Eisenberg.

Of the same cartridge case?

Mr. Nicol.

Same cartridge case in a different position, rotated in a different position.

Mr. Eisenberg.

May I have permission to introduce this as 624, Mr. Chairman?

Mr. Dulles.

It may be admitted.
(The photograph described was marked Commission Exhibit No. 624 and was received in evidence.)

Mr. Nicol.

If we compare 624 and 621 in the same general fashion, again we we have a match of the individual characteristics. So that again the same mechanical operation occurred on this cartridge case, 543, three different times, and in a rather random fashion. They are not the angular relationship between each of these sets of patterns--it is not divisible by any particular number. It is just a random occurrence.
Associated with this is another mark that occurs on all three of the positions, however not in any particular relationship to the group. of lines, and perhaps not as definitive. And it was on the basis of the match of these patterns that I would conclude that this cartridge had been introduced into a chamber at least three times prior to its final firing. So that this would represent, you might say, a practice or dry-run loading the gun and unloading it for purpose of either determining its--how it functions, or whether it was in proper function, or just for practice.

Mr. Eisenberg.

Just to review this testimony, Mr. Nicol, this is a mark which occurs on the base of the cartridge case, is that correct?

Mr. Nicol.

That is correct.

Mr. Eisenberg.

And are you able to say definitely whether it is an extractor or an ejection mark or a chambering mark?

Mr. Nicol.

It appears to me to be an extractor mark, although I was not able to identify this as similar to any extractor mark or any other marks on either Q-7 or 544 or any of the tests, 557.

Mr. Eisenberg.

Did extractor marks appear on those other cartridge cases?

Mr. Nicol.

Yes, sir.

Mr. Eisenberg.

And when you say you were not able to identify them, do you mean that they were not identical to or--

Mr. Nicol.

They were absent.

Mr. Eisenberg.

They were absent?

Mr. Nicol.

Absent in all the other cases.

Mr. Eisenberg.

So that extractor marks did not appear in the other cases?

Mr. Nicol.

Extractor marks appeared, but these marks did not appear.

Mr. Eisenberg.

Well, two sets of extractor marks have been put on--

Mr. Nicol.

This would be possible perhaps the violence with which the weapon was activated in this particular incident--or it might be the result of something not associated with the internal mechanism of the weapon, but might be the result of the charger or the cartridge carrier that is introduced into--the way the cartridges are introduced into the magazine.

Mr. Eisenberg.

Now, what led you to the conclusion that this was an ex tractor mark?

Mr. Nicol.

Only that it appears at the location of the cartridge case where an extractor mark would normally be found. That is to say, this would be the mark where the extractor strikes the edge of the case, and then springs around as the cartridge is driven into the chamber.

Mr. Eisenberg.

But you could not definitely say whether it is an extractor