The controversial US legal case (1920–27) in which two Italian immigrants, Nicola Sacco and Bertolomeo Vanzetti, were found guilty of murder. Many have alleged that their conviction resulted from prejudice against them as immigrants, anarchists, and evaders of military service. Following the trial there were anti-US demonstrations in Rome, Lisbon, and Montevideo, and one in Paris, where a bomb killed 20 people. For six years efforts were made to obtain a retrial without success, although the judge was officially criticized for his conduct; the two men were electrocuted in August 1927. The affair helped to mobilize opinion against the prevailing isolationism and conservatism of the post-war USA. Later evidence pointed to the crime having been committed by members of a gang led by Joe Morrelli.