For the jury, the experts’ testimony was the most tedious part of the trial—“a wilderness of lands and grooves,” as the Boston Post put it. Through the long sticky days the jurymen fidgeted, fanning themselves as the voices droned on. Captain Proctor of the State Police led off for the prosecution. From the time he had arrived at South Braintree the night of the murders until Katzmann appointed Chief Stewart, he had been in charge of the investigation. At the very beginning he felt that the holdup with its careful timing was a professional job, and after the arrest of Sacco and Vanzetti he told Katzmann that Stewart had got hold of the wrong men. He still felt so. It was not, however, about his theories but as a ballistics expert that the white-haired Proctor now testified. Only three days before taking the stand he and his colleague Charles Van Amburgh and the defense expert James Burns had fired fourteen test bullets through Sacco’s automatic into a box of oiled sawdust. The recovered bullets were compared with the mortal Bullet III. That bullet had a milled groove around it (known as a cannelure) that had been discontinued in more recent Winchester bullets of the same caliber. Burns was unable to obtain any of the older Winchesters corresponding to Bullet III, so used U.S. bullets as most closely resembling the obsolete type.[9] To John Dever, Proctor seemed a reluctant witness. The captain first explained that he was accustomed to testing 38- and 32-caliber revolvers by pushing bullets through the barrel manually. When in his demonstration he showed himself unable to strip the Sacco pistol, Dever was not impressed. Proctor then told the jury that the five right-twist bullets had come from a Savage automatic. When the assistant district attorney asked him if he was sure, he replied: “I can be as certain of that as I can of anything.” However, when Williams asked his opinion as to whether Bullet III had been fired from Sacco’s Colt, Proctor phrased his answer in a much more measured manner. “My opinion is,” he told Williams, “that it is consistent with being fired by that pistol.” In the casual moment the ambiguity of the answer escaped Moore. Thomas McAnarney spotted it at once and nudged his brother, but wise in the ways of the police, he feared a trap. If he should now ask Proctor what he meant by consistent, Proctor might reply that he meant that the bullet had gone through the gun—and this would be so much the worse for the defendants. Thomas therefore said nothing. As for the four shells Bostock had picked up from the gravel walk, Proctor explained that Shell W—with the identifying Winchester W on it—had been fired in one pistol, the other three in another. He compared the indentation made by the firing pin on Shell W with the indentations on the test shells fired in Sacco’s pistol. The marks on both, he said, were consistent—again he used the word—with their being fired in the same weapon.