Sacco's pistol is also claimed to have passed in and out of police custody, and to have been dismantled several times, both in 1924 prior to the gun barrel switch, and again between 1927 and 1961. The main problem with these charges is that the match to Sacco's gun was based not only the .32 pistol, but also to the same-caliber bullet that killed Berardelli, as well as to spent casings found at the scene. In addition to tampering with the pistol, the gun switcher/dismantler would also have had to access police evidence lockers and exchange the bullet from Berardelli's body and all spent casings retrieved by police, or else locate the actual murder weapon, then switch barrel, firing pin, ejector, and extractor, all before Goddard's examination in 1927 when the first match was made to Sacco's gun. However, skeptics of Sacco's guilt have repeatedly pointed to a single anomaly — that several witnesses to the crime insisted the gunman, alleged to be Sacco, fired four bullets into Berardelli. "He shot at Berardelli probably four or five times," one witness said. "He stood guard over him.” If this was true, many ask, how could only one of the fatal bullets be linked to Sacco's gun? In 1927, the defense raised the suggestion that the fatal bullet had been planted, calling attention to the awkward scratches on the base of the bullet that differed from those on other bullets. The Lowell Commission dismissed this claim as desperate but in 1985, historians William Kaiser and David Young made a compelling case for a switch in their book "Post-Mortem: New Evidence in the Case of Sacco and Vanzetti."