(Testimony of John F. Gallagher)
Mr. Gallagher.
Yes; I did.
Mr. Redlich.
With regard to the rifle cartridges, did you examine the cartridges which were actually found on the sixth floor of the Texas School Book Depository ?
Mr. Gallagher.
Yes; I did.
Mr. Redlich.
And did you determine that the elements barium and antimony were present on those particular cartridges?
Mr. Gallagher.
Yes; I did.
Mr. Redlich.
Are you able to give us your opinion as to the possible effect of the washing of the paraffin casts on the analysis which you performed? Let me rephrase the question. Did the fact that these casts were washed prior to the neutron activation test materially alter, in your opinion, the results of the neutron activation analysis ?
Mr. Gallagher.
I can say that the washing did not remove all the antimony and barium.
Mr. Redlich.
In your Opinion, would the washing of these paraffin casts remove substantial amounts of the elements barium and antimony if they were present on those casts ?
Mr. Gallagher.
Chemical treatment and washing will remove portions of the barium and antimony from these casts. This was determined from test casts which were studied in connection with these analyses, But it did not remove all the barium and antimony.
Mr. Redlich.
Can you describe exactly what you did with these paraffin casts in order to perform a neutron activation analysis ?
Mr. Gallagher.
Do you want me to tell who I worked with here?
Mr. Redlich.
Yes.
Mr. Gallagher.
These casts were taken to the Oak Ridge National Laboratory at Oak Ridge, Tenn., and there, with a Dr. Frank F. Dyer, and Mr. J. F. Emery, work was performed on these casts. The casts were studied under a binocular microscope. The surface of the casts were scraped. These paraffin scraping were put into a small container which was then placed in a pneumatic tube and sent into the heart of the research reactor to be bombarded by neutrons for a 3-minute period. The neutron flux was 6 times 10 to the 13th neutrons per square centimeter per second. After the 3 minutes were up, the container with its contents was discharged from the reactor.
The gamma ray spectrum was studied. And then chemical tests were made to precipitate barium and also to precipitate the antimony. The barium and antimony were quantitatively determined.
Mr. Redlich.
You stated in your answer that--
Mr. Gallagher.
Correction. Were quantitatively determined by studying the gamma rays emitted by the barium isotope 139 and the antimony isotope 122.
Mr. Redlich.
Now, according to your teStimony, you determined that the elements barium and antimony were present in the hand casts in an amount greater than would be expected in the case of a person who had not fired a revolver.
Mr. Gallagher.
Fired or handled a recently fired weapon.
Mr. Redlich.
Confining ourselves for the moment to the hand casts, does such a conclusion enable you to state that the person from whose hands these cases were made had in fact fired a revolver? The question I am asking you, Mr. Gallagher, is one designed to determine the extent to which the neutron activation technique is able to result in definitive judgments. Your initial answer was that the elements barium and antimony were present in these casts in an amount greater than would be expected from a person who had not either fired a weapon or handled a recently fired weapon. Are you able to, on the basis of this, make a judgment as to whether in fact the person from whose hands these casts were made had in your opinion fired a revolver, or handled a fired revolver? Do you understand my question, before you attempt to answer it?
Mr. Gallagher.
Well, first of all I reported that there was more on the hands than would be found on the hands of a normal individual who had not fired or handled a recently fired weapon. Now, I don't quite get the point of your question.
Mr. REDLICH. The point of my question is whether you are able, on the basis of
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