Mr. Barnes. That is what they call the dermal nitrate test, I believe is the correct name that they give it.
Mr. Belin. Does gunpowder generally have included in it some sort of nitrate compound?
Mr. Barnes. Yes.
Mr. Belin. If I were firing a pistol, would this pistol leave a nitrate on my hands that would be detectable by the paraffin test?
Mr. Barnes. It should, unless it is awful tight.
Mr. Belin. What do you mean by "awful tight"?
Mr. Barnes. You could have an automatic which very easily could keep you from having nitrate on your hands.
Mr. Belin. Well, let's assume that we were taking a .38 caliber pistol. You have seen the pistol which Lee Harvey Oswald had in his possession at the time he was apprehended.
Let's assume I were firing that pistol. Would it leave some residue on my hand?
Mr. Barnes. It should.