A payroll robbery, two men dead
On 15 April 1920, two men transporting a payroll in steel cash boxes for the Slater-Morrill Shoe Company in Braintree, Massachusetts were shot and killed by robbers who fled in a stolen car with the stolen money. Nicola Sacco and Bartolomeo Vanzetti, Italian immigrants and self-declared anarchists, were arrested on 5 May while carrying weapons and, according to prosecutors, giving evasive answers, and were indicted for murder that September. The Braintree trial ran from May to July 1921, with prosecutors presenting ballistics evidence linking a bullet to Sacco’s pistol, testimony placing both men near the scene, and their anarchist affiliations as circumstantial evidence of motive, while the defence offered alibi witnesses and challenged the jury selection process.
A cap that didn’t fit
The trial’s evidentiary record has been unusually heavily scrutinised in the century since, partly because of Harvard law professor Felix Frankfurter’s influential contemporary article arguing for a retrial, and partly because of repeated later ballistics re-examinations using improving comparison-microscope technology in 1927, 1935, 1961 and 1983. A cap found at the crime scene and presented as belonging to Sacco became a point of visible courtroom drama when he tried it on and it sat too small and too high on his head, prompting newspaper sketch artists to record the mismatch the next day; a police chief later admitted the cap had been tampered with after its discovery, further complicating its evidentiary value.
A judge who said the quiet part aloud
Trial judge Webster Thayer’s conduct has drawn sustained criticism from historians examining the case, based on reports that he privately remarked he would show that no long-haired anarchist from California could run his court, a statement, if accurately reported, suggesting open prejudgement inconsistent with impartial judicial conduct. Separately, in November 1925, a man named Celestino Medeiros confessed to the robbery and murders as part of a different criminal gang, evidence that defence appeals cited in seeking a new trial, but which Massachusetts courts declined to accept as grounds for reversing the convictions, leaving the confession part of the historical record without translating into legal relief for either defendant.
A confession that changed nothing
Physical evidence in the case remains genuinely disputed rather than clearly resolved in either direction. Ballistics expert William Proctor, who had testified for the prosecution that a bullet matched Sacco’s pistol, later signed an affidavit stating he could not positively make that identification, while a new barrel discovered on Sacco’s pistol in 1924, covered in manufacturer’s rust preventative, raised questions about possible evidence tampering that Judge Thayer investigated without reaching a conclusion. Later re-examinations using improved forensic technology in 1961 and 1983 reaffirmed a match between the fatal bullet and Sacco’s weapon, though historian David Kaiser has argued the bullet in question may have been substituted by the prosecution at some point, a claim that remains contested among specialists rather than settled.
Ballistics that keep getting re-examined
Both men were executed by electric chair just after midnight on 23 August 1927 at Charlestown State Prison, alongside Medeiros, despite worldwide protests in cities across North America, Europe, Asia and South America calling for clemency. Writer John Dos Passos, who reviewed the case for the defence committee, concluded Vanzetti was clearly innocent, while the letters both men wrote from prison, published after their deaths, were widely read as eloquent professions of innocence that shaped public sympathy for decades afterward. On the fiftieth anniversary of the executions in 1977, Massachusetts Governor Michael Dukakis issued a proclamation acknowledging the men had been unfairly tried and convicted, removing what he called the disgrace from their names, though he stopped short of issuing a formal pardon.
A proclamation, not a pardon
The case is worth studying for how thoroughly its evidence has been re-examined without producing consensus, a rare instance where forensic technology improved across five decades of re-testing the same physical exhibits and still left room for genuine disagreement among careful researchers. Reading it also means reading the First Red Scare’s climate directly into the courtroom, since the era’s mass arrests of anarchists and immigrants under Attorney General A. Mitchell Palmer shaped both how the case was investigated and how it was received by a jury and public primed to see foreign-born radicals as inherently suspect. Whether that climate produced a wrongful conviction or merely an unfairly conducted correct one remains, on the physical evidence alone, a genuinely open question.