O’Connor was aware—it was common newspaper knowledge—that the Travelers Insurance Company had insured the South Braintree payroll. Searching the back numbers of Protection, the Travelers publication, he found what he had assumed—an account of the South Braintree crime and a statement that the company had hired the Pinkerton Agency to investigate it. O’Connor realized that the agents must have made day-by-day reports of what they found, but what interested him even more was the obvious fact that these reports, which would have been submitted long before Sacco and Vanzetti were arrested, would be uncolored by preconceptions. If they could be located, O’Connor was certain they would prove to be the raw material of the case.
A week after the May Supreme Court decision O’Connor went to Thompson, then preoccupied with the Madeiros confession. Just what had occurred, he asked—well aware that Thompson did not have the answer—between the evening the Buick was stolen in Needham and the evening almost six months later when Sacco and Vanzetti were picked up on the streetcar? How did it happen they were arrested? All Thompson could do was to gesture helplessly and answer that he did not know. O’Connor then told him about the South Braintree Pinkerton report. Thompson, who had not heard of it before, banged his desk in his excitement.
Some days later, following Thompson’s request, a copy of the report arrived at the Travelers Boston office. Thompson was then away, but O’Connor managed to borrow the report and copy it. As he had hoped, it gave a picture of the case as it appeared before and just after Sacco and Vanzetti were picked up. O’Connor was particularly struck by Henry Hellyer’s notes on the fair brown-haired man Jenny Novelli had seen in the murder car who, by the time Hellyer testified at Dedham, had become black-haired with a dark complexion.
After this report came to light, O’Connor, while going through the files of the Bridgewater Independent, discovered references to a Pinkerton report on the Bridgewater holdup. But this second report, with its even more glaring discrepancies between the immediate impressions of witnesses and the evidence subsequently offered at the Plymouth trial, was not to come to light until 1927.
It had been common knowledge at the Dedham trial that the United States Department of Justice and District Attorney Katzmann’s office had cooperated in getting evidence for the prosecution. What was still not known was the degree of cooperation, for when Thompson raised the issue, the Bureau of Investigation followed its customary policy of refusing to open its files. Thompson increasingly came to feel that there might be evidence in the files indicating that Sacco and Vanzetti were innocent, and in any case he was outraged when he learned that the Bureau had placed spies in the Dedham jail and on the Defense Committee and had even planned to introduce one into Rosina Sacco’s house. He wrote to United States Attorney General John Sargent requesting that William West of the Boston office show him whatever documents and correspondence he had covering the investigations made before, during, and after the trial. In indirect answer to this, Thompson received a call from the Boston Bureau asking what information he was after. When he said that he wanted to go through whatever files the department had on Sacco and Vanzetti, West informed him that this would not be allowed.
If one can judge by a memorandum now in the National Archives and prepared by the Department of Justice at the request of the State Department on October 17, 1921, Sacco and Vanzetti, before their trial, were known merely as subscribers to Galleani’s Cronaca Sovversiva and a New Jersey anarchist paper, La Jacquerie. In the files Thompson particularly wanted to see there were of course the reports of the agents attending the trial, as well as the reports of Harold Zorian, who had infiltrated the committee, and Anthony Carbone, who had been planted in the Dedham jail.
Although he was unable to see the files, Thompson discovered that two former Bureau agents, Lawrence Letherman and Fred Weyand, were willing to sign affidavits as to what had taken place in the Boston office in regard to Sacco and Vanzetti during 1920 and 1921. Weyand explained quite frankly that the purpose of the Boston agents in going to the trial was to obtain enough evidence there to deport the accused as anarchists in case they were not convicted of murder.
Letherman, in his affidavit, corroborated Weyand:
The Department of Justice in Boston was anxious to get sufficient evidence against Sacco and Vanzetti to deport them, but never succeeded in getting the kind and amount of evidence required for that purpose. It was the opinion of Department agents here that a conviction of Sacco and Vanzetti for murder would be one way of disposing of these two men. It was also the opinion of such of the agents in Boston as had any actual knowledge of the Sacco-Vanzetti case, that Sacco and Vanzetti, although anarchists and agitators, were not highway robbers, and had nothing to do with the South Braintree crime. My opinion, and the opinion of most of the older men in the Government service, has always been that the South Braintree crime was the work of professionals.