I felt close enough to ask him one day, when whispers had reached me concerning Upton Sinclair’s distressing experiences in Boston:
“Carlo, would you feel free to tell me the truth about Sacco and Vanzetti?”
He answered: “Sacco was guilty but Vanzetti was not.”
At that moment some people entered the room where we were talking and I lost the chance to ask more. I lost it permanently, for I had no opportunity to see Carlo again before he was himself shot by an assassin.
The reasons for Tresca’s answer died with him, yet they must have been compelling or he would have skirted the question.
Thirteen years after Tresca’s death a new and conclusive series of ballistics tests was to bear him out. Many times postponed, they were finally conducted in the laboratory of the Massachusetts State Police on October 11, 1961, by Jac Weller, the honorary curator of the West Point Museum, and Colonel Frank Jury, a former head of the Firearms Laboratory of the New Jersey State Police.
The one certain method of determining whether two bullets have passed through the same gun barrel is examination with a comparison microscope, which brings the bullets together in one fused image. If the striations match, the conclusion is that both bullets were fired from the same weapon.
Using a comparison microscope and bullets they themselves had just fired from Sacco’s pistol, Weller and Jury determined beyond dispute that Bullet III had been fired from that pistol. The other five bullets, they found, had all been fired from a single unknown gun. As for the four shells that Bostock had picked up and given to Fraher, three had been fired in an unknown gun. Weller and Jury agreed, after comparing the breechblock markings of Shell W with those of a newly fired test shell, that Shell W had unquestionably been fired in Sacco’s pistol. Thus, the comparison microscope findings of 1961 confirmed the tests made by Major Goddard in 1927.
Turning to the question of a bullet substitution, Weller and Jury found it unlikely that the prosecution or its agents would have attempted to obtain suitable bullets by firing them from Sacco’s pistol into a side of beef; such a deception would not only have been difficult to keep secret, but the method would have offered no certainty of a plausibly lopsided bullet.
Captain Proctor had custody of the bullets and the guns, the bullets from the time of Berardelli’s autopsy until they were offered in evidence at the trial. If any substitution was made, Proctor was the only one with the extended opportunity to accomplish it. Van Amburgh was called to the trial as an outside expert; at that time he would have had neither the motive nor the occasion to make such a substitution.