THE TRIAL: II
Of the four bullets taken from Berardelli's body, plus the one removed from Parmenter in the Quincy hospital and the one found in his jacket, five had been fired from a 32-caliber pistol or pistols. The type was determined by measuring the lands (ridges) and the grooves impressed on the bullets by their passage through the barrel. In addition, the rifling had a right-hand twist that also left its mark.
The sixth bullet--the mortal one that Dr. Magrath had cut from Berardelli and marked with three needle scratches--had been fired from a 32-caliber automatic with a left-hand twist. Only the Colt among American automatics had such a twist. The question that four experts debated for several days was simply whether or not this bullet had been fired from the Colt found on Sacco.
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